Control system and control method of hybrid electrical vehicle (HEV)

Hybrid electric vehicle control system and control method technical field

[0001] The present invention relates to the field of automobile technology, and in particular to a control system of a hybrid electric vehicle and a control method of a hybrid electric vehicle.

Background technique

[0002] A hybrid electrical vehicle (Hybrid Electrical Vehicle, HEV for short) refers to a vehicle equipped with two power sources, namely, a thermal power source (generated by a traditional gasoline engine or a diesel engine) and an electric power source (generated by a battery and a motor). By using electric motors in hybrid vehicles, the power system can be flexibly adjusted according to the actual operating conditions of the vehicle, while the engine is kept working in the area with the best overall performance, thereby reducing fuel consumption and emissions.

[0003] Some of the existing hybrid vehicles use a series hybrid system, which is characterized in that the internal combustion engine system and the motor drive system each have a set of mechanical transmission mechanisms, and the two sets of mechanisms are combined with a planetary wheel structure to comprehensively adjust The direct speed relationship between the internal combustion engine and the electric motor.

[0004] However, the traditional hybrid vehicle has a single drive mode, and the driver cannot select the drive mode based on personal driving habits and long-term fixed driving conditions. For example, according to the habits of Asians, living is more concentrated, and the driving route to and from get off work is relatively fixed every day, and the distance is mostly within 50km. This special working condition is very suitable for short-to-medium-distance pure electric driving. The design concept of traditional hybrid electric vehicles is to reduce fuel consumption through motor-assisted adjustment of the engine instead of completely eliminating fuel consumption. Therefore, manual EV (pure electric) mode switching functions are often not available. Even if there is, pure electric driving continues due to battery capacity limitations. The mileage is short.

[0005] At the same time, the traditional hybrid electric vehicle does not use high-power, high-torque motors and engines due to the purpose of reducing fuel consumption, which will result in poor vehicle dynamics and reduced driving pleasure. For example, the acceleration time of some hybrid vehicles exceeds 10s per 100 kilometers, and the high-speed performance is also poor.

[0006] Furthermore, some hybrid electric vehicles adopt a hybrid structure and its control method, and there is no strategy of independent driving of the engine. Even when the engine is in a relatively economical working area, the battery will be charged by the first motor MG1. At the same time, it is necessary to adjust the engine speed through MG1 to realize gear shifting; and under heavy load acceleration conditions, limited by battery capacity, part of the engine power must drive MG1 to generate electricity before it can work with the battery to provide electric power to the second motor MG2. Both points reduce the driving efficiency of the engine. Moreover, in the engine start-off strategy, the set required power and vehicle speed limit are too small, and the vehicle speed switching condition is set to point instead of interval, which will cause the engine to start prematurely and frequently.

[0007] In addition, some existing hybrid vehicles do not adopt a plug-in structure due to their small battery capacity. The battery power is converted from gasoline, which increases the cost of use. At the same time, the hybrid structure is more complex, and ECVT (Electronic Continuously) is adopted. Variable Transmission, electronically controlled continuously variable automatic transmission) is difficult to match, and the cost is high.

Summary of the invention

[0008] The present invention is based on the following knowledge and discovery by the inventor:

[0009] In the related art, the powertrain control strategy of a typical hybrid electric vehicle in the HEV mode is roughly as follows: when the SOC of the power battery is high, the whole vehicle is purely electric under the starting conditions, starting conditions, and low speed conditions. Run, ECU (Electronic Control Unit) monitors the SOC value of the power battery, the actual power demand of the vehicle and other information in real time, and flexibly adjusts the engines

Start and stop; when the engine is started, planetary gears are used to achieve stepless speed change, which comprehensively adjusts the speed relationship between the engine and the motor. The hybrid vehicle has two motors, and MG1 performs speed control to adjust the speed ratio of the engine to the wheel end. MG2 performs torque control, provides torque and responds to driver and battery charging requirements.

[0010] However, when the SOC of the power battery is high, it is necessary to consider the power demand of the vehicle to switch between pure electric and hybrid power, which is likely to cause frequent start and stop of the engine, reduce the life of the starter, increase driving noise, and reduce Driving comfort: ECVT is used in the transmission mechanism, which has a high idle speed, high idle noise, fuel consumption and emissions. The addition of MG1 is used to adjust the engine speed and increase the cost of the motor. The ECVT has a complex structure, high process requirements, and difficulty in matching. , It also greatly increases the hardware and software costs of the transmission mechanism; under heavy-load acceleration conditions, limited by battery capacity, some of the engine power must drive MG1 to generate electricity before it can work with the battery to provide electric power to MG2. The number of energy conversions increases and reduces effectiveness.

[0011] The purpose of the present invention is to solve at least one of the above-mentioned technical defects.

[0012] To this end, an object of the present invention is to provide a control system for a hybrid electric vehicle. The engine power subsystem and the motor power subsystem in the control system of the hybrid electric vehicle are in parallel, so that the power is easily matched and the conversion efficiency is high. High, reduce fuel consumption and emissions, simple structure, short transmission matching cycle, and greatly reduce costs. In addition, the degree of reduction of the engine start and stop frequently, thereby increasing the life of the starter, reducing traffic noise, improve the driving comfort adaptability.

[0013] Another object of the present invention is to provide a control method for a hybrid electric vehicle.

[0014] In order to achieve the above objective, an embodiment of the present invention proposes a hybrid electric vehicle control system, including: a transmission device, the transmission device is used to drive the wheels of the hybrid vehicle; engine power subsystem, so The engine power subsystem is connected to the transmission device; the electric motor power subsystem is connected to the transmission device; and a controller that controls the engine power subsystem and the motor power sub The system controls the hybrid electric vehicle to enter the hybrid economic mode, and when the current gradient signal detected by the hybrid electric vehicle is less than or equal to the lower gradient threshold, and the soc of the power battery in the motor power subsystem is greater than or equal to the second power When the threshold and the maximum allowable discharge power of the power battery are greater than or equal to the first power threshold, the controller controls the hybrid electric vehicle to operate in an economical manner.

[0015] According to the control system of the hybrid electric vehicle according to the embodiment of the present invention, the engine power subsystem and the motor power subsystem are connected in parallel, which can effectively improve energy utilization compared with the existing hybrid electric vehicle power system adopting a series connection mode. At the same time, the parallel structure is relatively simple, avoiding the cumbersome ECVT matching of the parallel connection method, reducing the risk of irregularity caused by poor matching, greatly reducing the cost, and greatly improving the economic performance of the vehicle under the premise of ensuring the dynamic performance of the vehicle. In addition, the engine starting point is set higher, which can reduce the proportion of the engine involved in driving in urban working conditions and reduce fuel consumption and emissions. In addition, the frequent start and stop of the engine is avoided, thereby prolonging the life of the starter, reducing driving noise, and improving driving comfort.

[0016] In order to achieve the above objective, another embodiment of the present invention proposes a control method for a hybrid electric vehicle, wherein the hybrid electric vehicle includes a transmission device, an engine power subsystem, and a motor power subsystem. The device is respectively connected to the engine power subsystem and the motor power subsystem, and the control method includes the following steps: when the hybrid electric vehicle is running, the engine power subsystem and the motor power subsystem are controlled to control the vehicle. The hybrid electric vehicle enters the hybrid economic mode; the working state of the power battery in the motor power subsystem is detected, and the current gradient signal of the hybrid electric vehicle is detected; when the current gradient signal detected by the hybrid electric vehicle is less than or equal to When the slope lower limit threshold, the soc of the power battery is greater than or equal to the second power threshold, and the maximum allowable discharge power of the power battery is greater than or equal to the second power threshold, the hybrid electric vehicle is controlled to operate in an economical manner.

[0017] According to the control method of the hybrid electric vehicle of the embodiment of the present invention, the selectable working mode can meet the driving demand of the user under different working conditions, which can meet the electricity-only demand of urban working conditions, and can also meet the needs of suburban workers. The dynamic requirements of the situation, truly realize that the whole vehicle is driven by the user's subjective operation intention as the guide, and the driving pleasure is improved. In addition, the engine start point is set higher, which can reduce the proportion of the engine involved in driving in urban conditions and reduce fuel consumption and emissions. In addition, the frequent start and stop of the engine is avoided, thereby prolonging the life of the starter, reducing driving noise, and improving driving comfort.

[0018] Additional aspects and advantages of the present invention will be partly given in the following description, and part of them will become obvious from the following description, or be understood through the practice of the present invention.

Description of the drawings

[0019] The above and/or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0020] FIG. 1A is a block schematic diagram of a control system of a hybrid electric vehicle according to an embodiment of the present invention;

[0021] FIG. 1B is a block schematic diagram of a control system of a hybrid electric vehicle according to an embodiment of the present invention;

[0022] FIG. 2 is a schematic diagram of a signal flow of a hybrid electric vehicle according to an embodiment of the present invention;

[0023] FIG. 3 is a flowchart of a control method of a hybrid electric vehicle when the hybrid electric vehicle is operating in a pure electric economy mode according to an embodiment of the present invention;

[0024] FIG. 4 is a flowchart of a control method of a hybrid electric vehicle when the hybrid electric vehicle is operating in a pure electric sport mode according to another embodiment of the present invention;

[0025] FIG. 5 is a flowchart of a control method of a hybrid electric vehicle when the hybrid electric vehicle is operating in a hybrid economic mode according to another embodiment of the present invention;

[0026] FIG. 6 is a flowchart of a control method when the hybrid electric vehicle is operating in an economical manner when the hybrid electric vehicle is in a hybrid economic mode according to another embodiment of the present invention;

[0027] FIG. 7 is a schematic diagram of a working area of an engine when a hybrid electric vehicle is in a hybrid economic mode according to another embodiment of the present invention;

[0028] FIG. 8 is a schematic diagram of the corresponding curve relationship between the generated power of the motor and the SOC value of the power battery according to an embodiment of the present invention;

[0029] FIG. 9 is a flowchart of a control method when the hybrid electric vehicle is operating in a low-power mode when the hybrid electric vehicle is in a hybrid economic mode according to another embodiment of the present invention;

[0030] FIG. 10 is a flowchart of a control method of a hybrid electric vehicle when the hybrid electric vehicle is operating in a hybrid sport mode according to another embodiment of the present invention; and

[0031] FIG. 11 is a flowchart of a control method of a hybrid electric vehicle according to an embodiment of the present invention.

Detailed ways

[0032] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary, and are only used to explain the present invention, but cannot be construed as limiting the present invention.

[0033] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numerals and/or letters in different examples. This heavy

The repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and/or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the applicability of other processes and/or the use of other materials. In addition, the structure in which the first feature is "on" the second feature described below may include an embodiment in which the first and second features are formed in direct contact, or may include another feature formed between the first and second features. In the embodiment, the first and second features may not be in direct contact.

[0034] In the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, they may be mechanically connected or electrically connected. It may be the internal communication between the two elements, may be directly connected, or may be indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms can be understood according to specific circumstances.

[0035] These and other aspects of the embodiments of the present invention will be clear with reference to the following description and drawings. In these descriptions and drawings, some specific implementations of the embodiments of the present invention are specifically disclosed to show some ways of implementing the principles of the embodiments of the present invention, but it should be understood that the scope of the embodiments of the present invention is not This restriction. On the contrary, the embodiments of the present invention include all changes, modifications and equivalents falling within the scope of the spirit and connotation of the appended claims.

[0036] The following describes the control system and control method of a hybrid electric vehicle according to an embodiment of the present invention with reference to the accompanying drawings.

[0037] FIG. 1A is a schematic block diagram of a control system of a hybrid electric vehicle according to an embodiment of the invention. As shown in FIG. 1A, the control system of the hybrid electric vehicle includes a transmission device 10, an engine power subsystem 20, a motor power subsystem 30 and a controller 40.

[0038] Wherein, the transmission device 10 is used to drive the wheels 2a and 2b of the hybrid electric vehicle, the engine power subsystem 20 is connected to the transmission device 10, and the motor power subsystem 30 is connected to the transmission device 10. The controller 40 controls the hybrid vehicle to enter the hybrid economic mode by controlling the engine power subsystem 20 and the motor power subsystem 30, and when the current gradient signal detected by the hybrid vehicle is less than or equal to the lower gradient threshold, and the motor power When the SOC of the power battery in the subsystem 30 is greater than or equal to the first power threshold, and the maximum allowable discharge power of the power battery is greater than or equal to the second power threshold, the controller 40 controls the hybrid vehicle to operate in an economical manner.

[0039] According to an embodiment of the present invention, as shown in FIG. 1B, the engine power subsystem 20 includes an engine 3, a transmission 4, and the motor power subsystem 30 includes a motor 5, a reducer 6, a power battery 7, and an inverter 8. . Among them, the engine 3 is connected to the transmission device 10 through the transmission 4, the motor 5 is connected to the transmission device 10 through the reducer 6, and a power battery 7o that supplies power to the motor 5

[0040] In an embodiment of the present invention, the above-mentioned hybrid vehicle is a plug-in dual-mode hybrid vehicle, wherein the engine 3 is a high-efficiency turbocharged direct injection engine capable of outputting driving power, and the transmission 4 In order to transmit the output power of the engine 3 to the dual-clutch transmission, the power battery 7 is connected to the power electronic unit inverter 8 through a DC bus, and the inverter 8 is connected to the motor 5 through an AC three-phase line. The electric power and fuel power are at the transmission device 10. The coupling is carried out and transmitted to the wheels 2a and 2b. The user can select the working mode of the hybrid electric vehicle through the EV mode selection button, the HEV mode selection button, and the operation mode selection knob button.

[0041] According to an embodiment of the present invention, the working mode of a hybrid electric vehicle includes a pure electric mode and a hybrid economic mode, wherein the pure electric mode includes a pure electric economic mode (EV-eco mode) and a pure electric sports mode (EV -s mode), hybrid modes include hybrid economic mode (HEV-eco mode) and hybrid sports mode (HEV-s mode). Among them, the EV mode selection button is used to manually select the EV mode, the HEV mode selection button is used to manually select the HEV mode, and the operating mode selection knob button is used to manually switch between eco mode or Sport mode.

[0042] In the embodiment of the present invention, the manually switchable EV and HEV working modes, the manually switchable eco and Sport sports modes, the working mode states EV and HEV, whichever is one, and the sports mode states eco and Sport. Choose one of them, and use the mutual switching between modes to obtain four drive modes, namely EV-eco, EV-s, HEV-eco, HEV-s_oAmong them, the EV mode puts the vehicle in a pure electric energy consumption mode and keeps the engine inoperative; the HEV mode puts the vehicle in a hybrid energy consumption mode, and the motor cooperates with the engine or auxiliary drive or adjusts the engine to keep the overall performance at the highest level. Work in the best area; the eco mode limits the maximum output of the motor, engine, and power battery to ensure that the motor, engine, and power battery work in the most economical area; the Sport mode gives priority to meeting the power requirements of the vehicle without limiting the maximum output of the motor, engine, and power battery The output can obtain all the energy of the power system.

[0043] FIG. 2 is a schematic diagram of a signal flow of a hybrid electric vehicle according to an embodiment of the present invention. Referring to Figure 2, the gear controller SCU is responsible for collecting the gear signal and the EV/HEV/eco/Sport mode signal, and sends these two signals to the motor controller ECN. The motor controller ECN responds to the received EV/HEV/ The eco/Sport mode signal is verified and forwarded to the battery manager BMS, the engine controller ECM, the transmission controller TCU, and the combination instrument. At the same time, it executes the corresponding power system control plan according to different mode strategies and sends it to the engine controller ECM Engine start and stop commands and engine target torque signals; the battery manager BMS verifies the received EV/HEV/eco/Sport mode signals and executes energy management strategies; the engine controller ECM executes the engine system control plan and indicates the current engine torque Send it to the transmission controller TCU; the transmission controller ECN collects accelerator, brake, and vehicle speed signals, and executes gear shifts according to the transmission shift strategy; the combination instrument is used to display the current EV/HEV/eco/Sport mode.

[0044] In an embodiment of the present invention, the controller controls the hybrid vehicle to operate in a pure electric economy mode, a pure electric sport mode, a hybrid economy mode, and a hybrid electric vehicle according to the operating state of the hybrid electric vehicle and/or the working state of the power battery. Switch between hybrid sports modes.

[0045] Specifically, in an embodiment of the present invention, as shown in FIG. 3, when the hybrid electric vehicle is in the pure electric economy mode, if it is determined that the SOC of the power battery is less than or equal to the first power threshold, for example, 20% , Or when the maximum allowable discharge power of the power battery is less than or equal to the first power threshold, for example, 12KW, or the current gradient signal detected by the hybrid vehicle is greater than or equal to the gradient upper limit threshold, for example, 15%, the controller 40 controls the hybrid vehicle to switch to Hybrid economic model.

[0046] That is to say, in this embodiment, as shown in FIG. 3, the hybrid electric vehicle is driven in the EV-eco mode, and the power battery is used to power the motor to drive the vehicle without triggering the mode switching condition. Drive and keep the engine off. When the HEV button is manually pressed, the working mode of the hybrid electric vehicle is switched to HEV-eco mode; when the button is manually rotated to Sport, the working mode of the hybrid electric vehicle is switched to EV-s mode; when the mode button has no manual input, If the charge S0C of the power battery is less than or equal to the lower threshold of S0C, such as 20%, or the maximum allowable discharge power of the power battery is less than or equal to the lower threshold of power, such as 12KW, or the slope signal is greater than the upper threshold of slope, for example, 15%, the controller 40 automatically controls the hybrid power. The car switches to HEV-eco mode. Among them, in the EV-eco mode, in order to improve the efficiency of power consumption and extend the driving range, the maximum output power of the motor is limited, and the acceleration performance of the vehicle in this mode is considered, and the maximum output torque of the motor is not limited, that is, When the hybrid electric vehicle is in the pure electric economy mode, the controller 40 controls the hybrid electric vehicle to operate with limited power.

[0047] In another embodiment of the present invention, as shown in FIG. 4, when the hybrid electric vehicle is in the pure electric sport mode, if it is determined that the SOC of the power battery is less than or equal to the first power threshold, for example, 20%, or the power battery When the maximum allowable discharge power is less than or equal to the first power threshold 12KW, or the current gradient signal detected by the hybrid vehicle is greater than or equal to the upper gradient threshold, for example, 15%, the controller 40 controls the hybrid vehicle to switch to the hybrid sports mode.

[0048] That is to say, in this embodiment, as shown in FIG. 4, a hybrid electric vehicle running in the EV-s mode is driven, and the power battery provides power to the motor to drive the vehicle without triggering the mode switching condition. Drive and keep the engine off. When the HEV button is manually pressed, the working mode of the hybrid electric vehicle is switched to HEV-s mode; when the button is manually rotated to eco, the working mode of the hybrid electric vehicle is switched to EV-eco mode; when the mode button has no manual input, If the battery charge SOC of the power is less than or equal to the lower SOC threshold, such as 20%, or the maximum allowable discharge power of the power battery is less than or equal to the lower power threshold, such as 12KW, or the gradient signal is greater than the upper gradient threshold, such as 15%, the controller 40 automatically controls the mixing The powered car switches to HEV-s mode. Among them, in the EV-s mode, the first task is to obtain better power, so the motor output power is not limited.

[0049] As shown in FIG. 3 and FIG. 4, when the hybrid electric vehicle is in the pure electric economy mode or the pure electric sport mode, if the mode switching instruction of the user is received, that is, the mode switching condition is triggered, the controller controls the hybrid electric vehicle to switch To the target mode corresponding to the user's mode switching instruction.

[0050] Therefore, in the embodiment of the present invention, by selecting the EV operating mode and the eco/Sport operating mode, the hybrid electric vehicle can be in the EV-eco I operating mode or the EV-sI operating mode. Since the hybrid electric vehicle adopts a pluggable power battery charging structure, the power battery capacity is increased, and the motor with larger power and torque is selected, the hybrid electric vehicle can obtain strong power in the EV mode and can cope with all urban workers. It does not automatically switch to the HEV mode unless the slope signal is greater than the upper slope threshold, such as 15% (maximum grade of the EV mode). Unless manually switched, the HEV mode is kept running. . In the EV-eco working mode, the maximum output power of the motor is limited, and the maximum output torque of the motor is not limited to ensure low-speed climbing performance and high-speed economic performance. In the EV-sI operation mode, the maximum output power and maximum output torque of the motor are not limited to ensure the strongest power in the EV mode. The control system of the hybrid electric vehicle of the embodiment of the present invention ensures the power performance and driving range of the pure electric operation of the hybrid electric vehicle, and at the same time, it avoids long-term high-power electricity consumption to improve the efficiency of electricity consumption under the premise of meeting the dynamic requirements of the entire vehicle. . And to ensure that the hybrid vehicle continues to continue when the charge is low, the maximum allowable battery discharge power is insufficient, or the slope is large. The ability to operate normally, to avoid the situation that the power performance is degraded due to certain factors. At the same time, only one automatic mode switch is performed to avoid frequent start and stop of the engine, which plays an important role in improving the life of the starter, reducing noise, and improving driving comfort.

[0051] In yet another embodiment of the present invention, as shown in FIG. 5, when the hybrid electric vehicle is in the hybrid economy mode, after receiving the switching instruction to switch to the pure electric economy mode, the controller determines that the power battery When the SOC is greater than or equal to the second power threshold, for example, 30%, and the current speed of the hybrid vehicle is less than or equal to the first speed threshold, for example, 150km/h, the controller controls the hybrid vehicle to switch to the pure electric economy mode.

[0052] And, when the hybrid electric vehicle is in the hybrid economy mode, wherein, if the current gradient signal detected by the hybrid electric vehicle is less than or equal to the lower gradient threshold value, such as 5%, and the SOC of the power battery is greater than or equal to the second power threshold value, such as 30% , The maximum allowable discharge power of the power battery is greater than or equal to the second power threshold, such as 30KW, the controller controls the hybrid electric vehicle to operate in an economical manner; if the current gradient signal detected by the hybrid electric vehicle is less than or equal to the lower gradient threshold, such as 5%, and the S0C of the power battery Less than or equal to the first power threshold, such as 20%, or the current gradient signal detected by the hybrid vehicle is less than or equal to the lower gradient threshold, such as 5%, and the maximum allowable discharge power of the power battery is less than or equal to the first power threshold, such as 12KW, and the controller controls the hybrid vehicle Running in a low-power mode, wherein the second power threshold is greater than the first power threshold, and the second power threshold is greater than the first power threshold. It should be noted that, in the embodiments of the present invention, the low-power mode refers to that the engine drives the motor to quickly generate electricity, so as to get rid of the low-power state, so that the motor has the ability to adjust the working range of the engine again, thereby ensuring the economy of the entire vehicle.

[0053] In this embodiment, as shown in FIG. 6, when the hybrid electric vehicle is operating in an economical manner, if the vehicle speed of the hybrid electric vehicle is less than or equal to the second speed threshold, for example, 15 km/h, the controller controls the hybrid electric vehicle purely Electric driving. Moreover, when the hybrid electric vehicle is operating in an economical manner, if the vehicle speed of the hybrid electric vehicle is greater than or equal to the third speed threshold, for example, 30km/h, where the vehicle torque demand of the hybrid electric vehicle (the vehicle is running normally in the current state) When the required torque is greater than the preset torque upper limit curve of the engine, the controller controls the engine to output torque according to the preset torque upper limit curve, and controls the motor to make up the torque; when the vehicle torque demand of the hybrid electric vehicle is less than the engine's preset torque limit When the torque lower limit curve is set, the controller controls the engine to output torque according to the preset torque lower limit curve, and controls the motor to generate electricity; when the vehicle torque demand of the hybrid electric vehicle is less than or equal to the preset torque upper limit curve of the engine and greater than or equal to the engine When the torque lower limit curve is set, the controller controls the engine to meet the torque demand of the entire vehicle for torque output, and controls the motor to generate electricity. In this embodiment, the upper limit curve of the preset torque of the engine and the lower limit curve of the preset torque of the engine are shown in FIG. When the torque lower limit curve is between, the corresponding curve relationship between the generated power of the motor and the SOC value of the power battery is shown in Figure 8.

[0054] In this embodiment, as shown in FIG. 9, when the hybrid electric vehicle is running in a low-electric mode, if the current gear of the hybrid electric vehicle is in the non-P gear, the torque of the hybrid electric vehicle is When the demand is greater than the preset torque upper limit curve of the engine, the controller controls the engine to output torque according to the preset torque upper limit curve, and controls the motor to make up the torque; when the vehicle torque demand of the hybrid electric vehicle is less than the preset torque lower limit curve of the engine , The controller controls the engine to output torque according to the preset torque lower limit curve, and controls the motor to generate power; when the hybrid vehicle's entire vehicle torque demand is less than or equal to the engine's preset torque upper limit curve and greater than or equal to the engine's preset torque lower limit curve , The controller controls the engine to meet the vehicle torque demand for torque output, and controls the motor to generate electricity. Moreover, when the hybrid electric vehicle is running in a low-power mode, if the current gear of the hybrid electric vehicle is in the P gear, the controller controls the hybrid electric vehicle to enter the idle start-stop mode.

[0055] That is, in this embodiment, as shown in FIG. 5, when driving a hybrid electric vehicle running in the HEV-eco mode, when the EV button is manually pressed, only when the SOC of the power battery is greater than or equal to the SOC When the upper threshold is 30% and the current vehicle speed is less than or equal to the first speed threshold, such as 150km/h, the hybrid electric vehicle is allowed to switch to the EV-eco mode. Otherwise, the working mode is not switched; when you manually rotate the button to Sport, then The working mode of the hybrid electric vehicle is switched to the HEV-s mode; when the mode button has no manual input, the working mode of the hybrid electric vehicle remains the same as the HEV-eco mode, according to the power battery charge and the maximum allowable discharge power area of the power battery Divided, engine and motor are matched according to economic strategy and low power strategy respectively. As shown in Figure 6, the economic strategy requires that when the current speed of the hybrid vehicle is less than or equal to 15km/h, the hybrid vehicle is driven by pure electric power. When the current speed of the hybrid vehicle is greater than or equal to 30km/h, the engine participates in the drive until the vehicle speed drops. It resumes to pure electric drive only at 15km/h. If the motor alarms at this stage and the drive capacity is insufficient, the engine will be started. As shown in Figure 9, the low-power strategy cancels low-speed pure electric power, and adds the P-gear engine start-stop function. Among them, the low-power strategy and economic strategy control method after the engine is started. As shown in Figure 7, the curve design principle is that the area between the upper and lower limit curves contains the most economical area of the engine as much as possible, because the engine is in the upper and lower limit curves. In addition, the economy is poor. The motor assists the engine in this area. The engine will output the lower limit curve under the premise of meeting the demand of the whole vehicle when running at a small load. The excess torque is used for power generation. When running at a high load, the engine will output according to the upper limit curve. The motor is supplemented. If the motor is limited by itself or the power battery and the charging and discharging capacity is insufficient, the motor is charged and discharged according to the maximum allowable capacity of itself and the power battery, and the upper and lower limits of the engine output are cancelled at the same time. The engine outputs according to the demand of the whole vehicle;

The motor is mainly involved in power generation, and the power generation is a certain functional relationship with the current SOC value, as shown in Figure 8, but the total output torque of the engine does not exceed the limit of the upper limit curve. If the motor is limited by itself or the battery, the charging capacity is insufficient. When the motor is charged according to the maximum allowable capacity of itself and the battery; and the above-mentioned HEV-eco mode drive strategy is executed when the gradient signal does not exceed the upper gradient threshold, such as 15%, and when the gradient signal exceeds the upper gradient threshold, such as 15 %, in order to meet the vehicle climbing performance requirements, it is stipulated that the engine must be started at this time, and the upper and lower limit curve limits of the engine and the power limit of the motor are cancelled until the gradient signal is less than the lower gradient threshold, such as 5%, and the original execution strategy is restored.

[0056] In the embodiment of the present invention, in terms of the assembly structure of the control system of the hybrid electric vehicle, the control system of the hybrid electric vehicle of the embodiment of the present invention adopts one engine and one motor in parallel through a dual-clutch transmission, and related technologies The hybrid electric vehicle in the power system adopts one engine, one MG1, and one MG2 through planetary gear hybrid connection; in terms of engine start-stop strategy, the control system of the hybrid electric vehicle in the embodiment of the present invention does not consider the power demand of the whole vehicle. Within the gradient, only the vehicle speed starts and stops the engine and the vehicle speed switching point is relatively high. The engine always runs when the gradient is large, and the power system of the hybrid vehicle in the related technology also considers the vehicle speed, battery charging power demand, and vehicle drive power demand. , The vehicle speed switching point is low; from the perspective of the definition of the SOC value of the low-power strategy, the control system of the hybrid electric vehicle in the embodiment of the present invention defines less than 20% to enter the low-power strategy, while the power system definition of the hybrid electric vehicle in the related technology 45% or less; from the perspective of the idle start-stop strategy in the P gear, the control system of the hybrid electric vehicle of the embodiment of the present invention will stop the engine as long as the vehicle speed is 0, the gear is in the P gear, and the SOC value is not less than 20%. The power system of the hybrid electric vehicle in the technology should also consider the engine water temperature and the SOC value at a relatively high level; during the operation of the whole vehicle, the control system of the hybrid electric vehicle in the embodiment of the present invention will be more practical in terms of road conditions and economic strategies. Switch back and forth between low-power strategies, and The power balance is not always maintained, and the power system of the hybrid electric vehicle in the related technology enters the equilibrium state after a short period of operation; during the operation of the engine, the control strategy is determined by the difference in the assembly structure. There is a big difference. The control system of the hybrid electric vehicle of the embodiment of the present invention can keep the engine in a larger economic working area. It can be known from the universal characteristics of the engine that if the engine is to work in the most efficient area, the engines The load is large, the vibration and noise of the vehicle are significantly increased, and the comfort is greatly reduced. The control system of the hybrid electric vehicle of the embodiment of the present invention makes the engine work range wide, so this effect is reduced to a lower level. The engine working area of the power system of a hybrid electric vehicle is narrow. At this time, the engine load is large, and the vehicle's NVH (Noise, Vibration, Harshness (noise, vibration and harshness) has decreased significantly. The MG1 of the hybrid vehicle power system in the related art needs to adjust the speed at all times to adjust the engine speed, and the engine idling speed is as high as 1200rpm, while the engine idling speed in the hybrid vehicle control system of the embodiment of the present invention is about 800rpm, and Only use the dual-clutch 6 gears, the gear shift matching is relatively simple; the power of the engine in the control system of the hybrid electric vehicle in the embodiment of the present invention is either fully driven or partially driven and partly generated to the battery, while the hybrid in the related technology When the power system of a powered vehicle is running at medium to large loads, a part of the engine's energy is always first generated by MG1 and then given to MG2 to drive the hybrid vehicle.

[0057] Therefore, due to the limited battery and motor capabilities of the power system of the hybrid vehicle in the related art, the vehicle power and vehicle speed switching points for engine start and stop are set low, which will cause the engine to start and stop prematurely and frequently, and the engine runs. The increase in the proportion is not conducive to reducing fuel consumption and emissions under urban operating conditions, and the control system of the hybrid electric vehicle of the embodiment of the present invention has a relatively strong pure electric driving capability and can meet most of the driving requirements, so the engine start point is relatively set High, which can reduce the proportion of the engine involved in driving in urban operating conditions, and achieve the purpose of reducing fuel consumption and emissions in urban operating conditions. At the same time, the user operates the accelerator to make the vehicle power demand change more and more frequently, thereby avoiding the judgment of the vehicle power, reducing the frequent start and stopping of the engine, which is beneficial to extend the life of the starter motor, reduce noise, improve comfort, and also reduce the high throttle. The power shock at the moment the engine starts when accelerating and climbing improves driving safety and comfort. The power of hybrid electric vehicles in related technologies

The system needs to consider the S0C value of the power battery and the water temperature of the engine when the system is at idle and P gear idle speed. It is not directly controlled by humans, which is not conducive to the customer's grasp of the operating rules. The S0C value is too large due to the small battery capacity. It is easy to cause the engine to wait for the red light to hang the P gear without stalling. At this time, the parking noise is increased, and the comfort is greatly reduced; at the same time, the engine idling speed is limited by the transmission mechanism to 1200rpm, and the engine noise and fuel consumption are higher than ordinary fuel vehicles. In most cases, the control system of the hybrid electric vehicle of the embodiment of the present invention will stall the engine when the P gear is at rest, which is helpful for the user to master the operating rules, reduce the noise during parking, and improve the parking comfort. The idling speed of the engine is comparable to that of traditional fuel. The car is quite. In addition, the battery power in the control system of the hybrid electric vehicle in the embodiment of the present invention is not made into a balance strategy, and the operating state of the entire vehicle will automatically switch between the economic strategy and the low-power strategy according to the actual working conditions, which can further highlight that the motor adjusts the engine. The function of the working area is conducive to further reducing the emission and fuel consumption, and the transmission mechanism of the control system of the hybrid electric vehicle in the embodiment of the present invention adopts a dual-clutch transmission, which has a simple structure and a short transmission matching period, thereby greatly reducing costs; when the engine is driven by hybrid power The motors are connected in parallel, the control strategy is easier to match, and the power conversion efficiency is high. Finally, the power generation strategy of the control system of the hybrid electric vehicle in the embodiment of the present invention adopts the dynamic change associated with the power battery SOC to make the whole The car can maintain a high battery level during normal low-to-medium load driving.

[0058] In yet another embodiment of the present invention, as shown in FIG. 10, when the hybrid electric vehicle is in the hybrid sports mode, after the controller receives the switching instruction to switch to the pure electric sports mode, if it determines that the power battery When the S0C of is greater than or equal to the second power threshold, for example, 30%, and the current speed of the hybrid vehicle is less than or equal to the first speed threshold, for example, 150km/h, the controller controls the hybrid vehicle to switch to a pure electric sport mode.

[0059] Moreover, when the hybrid electric vehicle is in the hybrid sports mode, if the current gear of the hybrid electric vehicle is in the P gear, the controller controls the hybrid electric vehicle to enter the idle start-stop mode. When the hybrid electric vehicle is in the hybrid sports mode, if the current gear of the hybrid electric vehicle is in the non-P gear, among which, when the vehicle torque demand of the hybrid electric vehicle is greater than the preset peak torque of the engine, the controller controls the engine according to The preset peak torque is used for torque output, and the motor is controlled to make up the torque; when the vehicle torque demand of the hybrid electric vehicle is less than or equal to the preset peak torque of the engine, the controller controls the engine to meet the vehicle torque demand for torque output, and controls the motor To generate electricity.

[0060] That is to say, in this embodiment, as shown in FIG. 10, when driving a hybrid electric vehicle running in HEV-s mode, when the EV button is manually pressed, only when the power battery's charge SOC is greater than or equal to SOC ±Limit threshold, such as 30%, and the vehicle speed is less than or equal to the first speed threshold, such as 150km/h, the hybrid electric vehicle is allowed to switch to the EV-s mode, otherwise it will not switch to the working mode; when the button is manually turned to eco, then The working mode of the hybrid electric vehicle is switched to the HEV-eco mode; when the mode button has no manual input, the working mode of the hybrid electric vehicle remains the same as the HEV-s mode. The HEV-s mode strategy is similar to the HEV-eco low-power strategy. The low-speed pure electric is cancelled, and the P gear engine start-stop function is added, the power limit of the motor is cancelled, and the upper and lower limits of the engine torque are cancelled. Both the engine and the motor can have peak output. This working mode can obtain the best power performance.

[0061] In the embodiment of the present invention, when the engine starts to run, a dual-clutch transmission is used to transmit engine power and perform gear shifting. When the whole vehicle is in HEV-eco mode and HEV-s mode, two sets of shifting strategies are matched respectively. HEV-eco mode focuses on reducing fuel consumption. The matching principle of shifting strategies is to make the engine work in a high-efficiency area as much as possible. The shift point will be slightly advanced, and the engine will mostly work in the speed range of 1500~2000rpm during driving; HEV-s mode focuses on power, the matching principle of shift strategy is to make the torque transmitted by the engine to the wheel end as large as possible to obtain better For driving performance, the shift points of each gear will lag slightly, and for full throttle acceleration, the shift point is set at the maximum torque point of the engine's inherent characteristics calibrated in each gear, and the acceleration performance can be maximized.

[0062] In an embodiment of the present invention, when the hybrid electric vehicle is in the pure electric economy mode,

The upper limit of the current output power of the power battery is less than the first preset power; when the hybrid electric vehicle is in the pure electric sport mode, the upper limit of the current output power of the power battery is less than the second preset power, wherein the The second preset power is greater than the first preset power; when the hybrid electric vehicle is in the hybrid economic mode, the current output power upper limit of the power battery and the current output power upper limit of the engine are both less than all The first preset power, and the upper limit of the current output torque of the engine is less than the first torque threshold; when the hybrid electric vehicle is in the hybrid sport mode, the upper limit of the current output power of the power battery is less than the first torque threshold; 2. The power is preset, and the engine allows the current output torque upper limit and the current output power upper limit to output. In an example of the present invention, the first preset power may be 70KW, the second preset power may be 110KW, and the first torque threshold may be 185N·Mο [0063] That is, the The pure electric economy mode is that the hybrid electric vehicle is in the pure electric energy consumption mode, the current output power upper limit of the power battery is less than the economic mode power upper limit, for example, 70KW, and the power battery works in the most economical area; the pure electric sports mode is , The hybrid electric vehicle is in the pure electric energy consumption mode, and the current output power upper limit of the power battery is less than the sports mode power upper limit, for example, 110KW; the hybrid economic mode is hybrid power When the car is in hybrid energy consumption mode, the current output power limit of the power battery is less than the economic mode power upper limit, such as 70KW, and the current engine output power limit is also less than the economic mode power upper limit, such as 70KW, and the current engine output torque upper limit is less than The upper limit of the torque in the economy mode is 185N·M, which makes the engine and power battery work in the most economical area; the hybrid sports mode is that the hybrid electric vehicle is in the energy consumption mode of the hybrid power, and the current output power upper limit of the power battery is less than the power of the sports mode The upper limit is for example 110KW, and the engine allows the current upper limit of torque and power of the engine to output.

[0064] It should be noted that in the embodiment of the present invention, the most economical area in the pure electric mode means that as the discharge power of the power battery increases, the working efficiency of the power battery decreases correspondingly, so the vehicle power performance ( Under the premise of operating performance and acceleration performance), the power battery preferentially uses a lower discharge power to work. The most economical area in the hybrid mode means that as the discharge power of the power battery increases, the working efficiency of the power battery decreases accordingly. Therefore, on the premise of meeting the vehicle dynamics (operating performance and acceleration performance), the power battery is preferred to be used. Work with low discharge power. The most economical area of the engine is determined by the torque and speed of the engine. As shown in Figure 7, the abscissa represents the engine speed, and the ordinate represents the engine torque. It can be seen from the figure that at different speeds, With appropriate torque, the most economical area of the current engine can be obtained. If the engine torque is too high at this time, the engine torque will be reduced and the motor will provide torque supplement; if the engine torque is too low, the engine will be increased accordingly Torque. At this time, the vehicle does not need the increased engine torque for driving, so the energy generated by the increased engine torque is recovered and used for electric motor power generation.

[0065] In addition, the economic mode power upper limit can be understood as the upper limit of the output power in the most economical area where the power battery or the engine keeps working. The upper limit of the power of the sport mode is of its own unique nature. The power battery or engine output is output according to the current maximum torque or power of the engine or the current maximum power of the power battery. At this time, the power system provides power or torque output for the vehicle with the maximum energy.

[0066] In addition, it can be understood that the working mode when the hybrid electric vehicle is started is still the working mode when the hybrid electric vehicle was turned off last time. In addition, the hybrid electric vehicle also has a fuel-only mode, and the fuel-only mode is a failure mode.

[0067] According to the control system of the hybrid electric vehicle of the embodiment of the present invention, the engine power subsystem and the motor power subsystem are connected in parallel, which can effectively improve energy utilization compared with the existing hybrid electric vehicle power system adopting a series connection. At the same time, the parallel structure is relatively simple, avoiding the cumbersome ECVT matching of the parallel connection method, reducing the unevenness risk caused by poor matching, greatly reducing the cost, and greatly improving the economic performance of the vehicle under the premise of ensuring the dynamic performance of the vehicle. and

In addition, the power performance and driving range of the pure electric operation of the whole vehicle are guaranteed, and long-term high-power electricity consumption is avoided on the premise of meeting the power requirements of the whole vehicle to improve power consumption efficiency. In addition, the frequent start and stop of the engine is avoided, thereby prolonging the life of the starter, reducing driving noise, and improving driving comfort. Finally, because the engine starting point is set higher, the proportion of the engine involved in driving in urban conditions can be reduced, fuel consumption and emissions can be reduced, and it will be more energy-saving and environmentally friendly.

[0068] Hereinafter, the control method of the hybrid electric vehicle proposed according to the embodiment of the present invention will be further described with reference to FIGS. 3 to 11. Wherein, the hybrid vehicle includes a transmission device, an engine power sub-system and a motor power sub-system, and the transmission device is connected to the engine power sub-system and the motor power sub-system respectively.

[0069] FIG. 11 is a flowchart of a control method of a hybrid electric vehicle according to an embodiment of the present invention. As shown in FIG. 11, the control method of the hybrid electric vehicle includes the following steps:

[0070] S1, when the hybrid electric vehicle is running, control the engine power subsystem and the motor power subsystem to control the hybrid economic mode of the hybrid electric vehicle.

[0071] According to an embodiment of the present invention, the working mode of a hybrid electric vehicle includes a pure electric mode and a hybrid mode, wherein the pure electric mode includes a pure electric economic mode and a pure electric sport mode, and the hybrid mode includes a hybrid economic mode And hybrid sports mode.

[0072] S2, detecting the working state of the power battery in the motor power subsystem, and detecting the current gradient signal of the hybrid electric vehicle.

[0073] S3, when the current gradient signal detected by the hybrid electric vehicle is less than or equal to the lower gradient threshold, and the power battery

When the S0C is greater than or equal to the second power threshold, and the maximum allowable discharge power of the power battery is greater than or equal to the second power threshold, the hybrid electric vehicle is controlled to operate in an economical manner.

[0074] In an embodiment of the present invention, as shown in FIG. 3, the control method of the hybrid electric vehicle when the hybrid electric vehicle is operating in the pure electric economy mode includes the following steps:

[0075] S101. Acquire manual mode button switching information, which may be HEV mode button switching operation, Sport mode button switching operation, or modeless button switching operation, that is, it is judged whether to perform manual switching, if yes, go to step S102; if No, go to step S103o

[0076] S102, receiving a mode button switching operation, switching the working mode, switching to another working mode, and executing a corresponding power system control strategy. That is to say, when the hybrid electric vehicle is in the pure electric economy mode, if the user's mode switching instruction is received, the controller controls the hybrid electric vehicle to switch to the target mode corresponding to the user's mode switching instruction.

[0077] S103, the modeless button switching operation is received, and the working mode is not switched. At this time, the current SOC value of the power battery, the maximum allowable discharge power Pb of the power battery, and the detected gradient signal i of the hybrid electric vehicle are combined with the three The set thresholds are compared separately, that is, the lower limit of the S0C threshold S0C_downFor example, 20%, the lower limit threshold Pbdm of the maximum allowable discharge power of the power battery, for example 12KW, the upper limit threshold of the slope i_upFor example, 15%, and judge whether it meets SOC W S0C_dom.Pb W Pb_down. iup W i °

[0078] S104, if at least one of the three conditions in step S103 is met, the working mode of the hybrid electric vehicle is automatically switched to the HEV-eco mode, that is, if the SOC of the power battery is less than or equal to the first power threshold, for example, 20%, Or when the maximum allowable discharge power of the power battery is less than or equal to the first power threshold, such as 12KW, or the current gradient signal detected by the hybrid vehicle is greater than or equal to the upper gradient threshold, such as 15%, the hybrid vehicle is controlled to automatically switch to the hybrid economy mode.

[0079] S105: If none of the three conditions in step S103 are met, then the HEV-eco mode is not automatically switched, and the hybrid operation is not performed.

Limo keeps running in EV-eco mode.

[0080] When the hybrid electric vehicle is driven in the EV-eco mode, the motor is always driven as a single power source when the manual or automatic mode is not switched. The primary purpose of this working mode is to save electricity on the premise of meeting the power requirements of the vehicle. Long-term high-power electricity consumption should be avoided to improve electricity efficiency. Therefore, the maximum output power of the motor is limited to π%, such as 70KW, while meeting the requirements. The climbing performance of the vehicle does not limit the maximum output torque of the motor, that is, when the hybrid electric vehicle is in the pure electric economy mode, the hybrid electric vehicle is controlled to run at a limited power.

[0081] From the embodiment of the control method when the hybrid electric vehicle is in the EV-eco mode, it can be seen that the hybrid electric vehicle is controlled to automatically switch to the HEV by judging the SOC value of the power battery, the maximum allowable discharge power of the power battery, and the gradient value. The eco-mode strategy ensures the ability of the vehicle to continue to operate normally and avoids the possibility of a decrease in power performance due to certain factors. In summary, the above control method when the hybrid electric vehicle is in the EV-eco mode ensures that the motor battery always works in the high-efficiency area under the premise of satisfying the dynamics of the whole vehicle, so as to realize the long range of pure electric hybrid electric vehicle, low operating cost, and emission. dramatically drop.

[0082] In another embodiment of the present invention, as shown in FIG. 4, the control method of the hybrid electric vehicle when the hybrid electric vehicle is running in the pure electric sport mode includes the following steps:

[0083] S201. Acquire manual mode button switching information, which may be HEV mode button switching operation, eco mode button switching operation, or no mode button switching operation, that is, it is judged whether to perform manual switching, if yes, go to step S202; if No, go to step S203o

[0084] S202, receiving the mode button switching operation, switching the working mode, switching to other working modes, and executing the corresponding power system control strategy. That is to say, when the hybrid electric vehicle is in the pure electric sport mode, if the user's mode switching instruction is received, the hybrid electric vehicle is controlled to switch to the target mode corresponding to the user's mode switching instruction.

[0085] S203, the modeless button switching operation is received, and the working mode is not switched. At this time, the current SOC value of the power battery, the maximum allowable discharge power Pb of the power battery, and the detected gradient signal i of the hybrid electric vehicle are combined with the three The set thresholds of SOC are compared separately, namely the lower limit of SOC threshold SOC_downFor example, 20%, the lower limit threshold Pbdm of the maximum allowable discharge power of the power battery, for example 12KW, the upper limit threshold of the slope i_upFor example, 15%, and judge whether it meets SOC W SOC_dom.Pb W Pb_down. iup W i °

[0086] S204, if at least one of the three conditions in step S203 is met, the working mode of the hybrid electric vehicle is automatically switched to the HEV-s mode, that is, if the SOC of the power battery is less than or equal to the first power threshold, for example, 20%, Or when the maximum allowable discharge power of the power battery is less than or equal to the first power threshold, such as 12KW, or the current gradient signal detected by the hybrid vehicle is greater than or equal to the upper gradient threshold, such as 15%, the hybrid vehicle is controlled to automatically switch to the hybrid sports mode.

[0087] S205, if none of the three conditions in step S203 are met, then the automatic switching of the HEV-s mode is not performed, and the hybrid electric vehicle keeps running in the EV-s mode.

[0088] When the hybrid electric vehicle is driven in the EV-s mode, the motor is always driven as a single power source when the manual or automatic mode is not switched. This working mode does not limit the maximum output torque and power of the motor, and can obtain the maximum capacity of the motor to drive, meeting the user's higher dynamic requirements in the EV mode (such as overtaking acceleration, fast climbing, etc.).

[0089] From the embodiment of the control method when the hybrid electric vehicle is in the EV-s mode, it can be seen that the hybrid electric vehicle is controlled to automatically switch to the HEV by judging the SOC value of the power battery, the maximum allowable discharge power of the power battery, and the gradient value. The S-mode strategy ensures the continuous and normal operation of the whole vehicle and avoids the deterioration of power performance due to certain factors.

may. In summary, the above-mentioned control method for hybrid electric vehicles in EV-s mode is suitable for users who want both pure electric operation and a better sense of power. The working mode is more flexible and changeable, so that users can get more driving pleasure. .

[0090] In another embodiment of the present invention, as shown in FIG. 5, the control method of the hybrid electric vehicle when the hybrid electric vehicle is operating in the hybrid economic mode includes the following steps:

[0091] S301. Acquire EV mode key switch information, and determine whether to manually switch the EV mode, if yes, go to step S302 or step S303; if not, go to step S306.

[0092] S302, receiving the EV mode button switch operation, compare the current SOC value of the power battery with the set SOC upper threshold SOC®, for example 30%, to determine whether the SOCup W SOC is satisfied, and if so, proceed to step S303; if not, go to step S305o

[0093] S303. Compare the current vehicle speed with a set vehicle speed threshold, such as 150km/h, that is, the maximum vehicle speed that allows the HEV mode to be switched to the EV mode, and determine whether vWV^ is satisfied, and if so, go to step S304; if not, Then go to step S305o

[0094] S304, control the hybrid electric vehicle to switch to the EV-eco mode and execute the corresponding power system control strategy.

[0095] That is, when the hybrid electric vehicle is in the hybrid economy mode, after the controller receives the switching instruction to switch to the pure electric economy mode, if it determines that the SOC of the power battery is greater than or equal to the second power threshold, for example, 30%, And when the current vehicle speed of the hybrid electric vehicle is less than or equal to the first speed threshold, for example, 150km/h, the controller controls the hybrid electric vehicle to switch to the pure electric economy mode.

[0096] S305, the hybrid electric vehicle keeps running in the HEV-eco mode.

[0097] S306, after receiving the no-EV mode button switching operation, acquire the Sport mode button switching information, and determine whether to manually switch the Sport mode, if yes, proceed to step S307; if not, proceed to step S308.

[0098] S307, after receiving the sport mode button switching operation, control the hybrid electric vehicle to switch to the HEV-s mode and execute the corresponding power system control strategy.

[0099] S308, when the switch operation of the non-Sport mode button is received, the working mode of the hybrid electric vehicle is not switched, and the slope information is obtained, and the current slope value i and the set slope upper and lower limit thresholds are set, for example, 15%. 5% is compared, and the interval of i value is judged.

[0100] S309: Determine whether i W id^n, and proceed to the next step S310.

[0101] S310. Compare the current SOC value of the power battery and the maximum allowable discharge power Pb of the power battery with the set thresholds of the two respectively, that is, the upper and lower SOC thresholds SOC® such as 30%, SOCd^ such as 20%, the power battery The maximum allowable discharge power upper and lower limit threshold P% such as 30KW, Pb_downFor example, 12KW, judge the interval of SOC and Pb.

[0102] S311, determine that SOCup W SOC and Pb® W Pb, and proceed to step S312.

[0103] S312, the hybrid electric vehicle is controlled according to an economic strategy workflow.

[0104] That is, when the hybrid electric vehicle is in the hybrid economy mode, if the current gradient signal detected by the hybrid electric vehicle is less than or equal to the lower gradient threshold value, for example, 5%, and the SOC of the power battery is greater than or equal to the second power threshold value, for example, 30% , The maximum allowable discharge power of the power battery is greater than or equal to the second power threshold, such as 30KW, and the controller controls the hybrid electric vehicle to operate in an economical manner.

[0105] S313, determine the SOC_up>SOC>SOC_dom And Pb_up W Pb, or SOC_up W SOC and Pb_up>Pb>Pb_down, Go to step S314o

[0106] S314, the hybrid electric vehicle is controlled according to the original strategy workflow, that is, it is still executed according to the economic strategy flow when it was originally operated in an economical mode, and the low electricity strategy process is still executed when it was originally operated in a low power mode.

[0107] S315, determine SOC W S0C_dom Or Pb W goes to step S316.

[0108] S316, the hybrid electric vehicle is controlled according to the low-power strategy workflow.

[0109] That is to say, when the hybrid electric vehicle is in the hybrid economic mode, if the current gradient signal detected by the hybrid electric vehicle is less than or equal to the lower gradient threshold value, such as 5%, and the SOC of the power battery is less than or equal to the first power threshold value, such as 20%, Or the current gradient signal detected by the hybrid vehicle is less than or equal to the lower gradient threshold, such as 5%, and the maximum allowable discharge power of the power battery is less than or equal to the first power threshold, such as 12KW. The controller controls the hybrid vehicle to run in a low-power mode, where the second The power threshold is greater than the first power threshold, and the second power threshold is greater than the first power threshold.

[0110] S317, determine i_up>i>i_dom, Go to step S318o

[0111] S318, the hybrid electric vehicle is controlled according to the original strategy workflow, that is, the control strategy when i W i ^ n or W i is maintained respectively.

[0112] S319, determine GWi, go to step S320o

[0113] S320, controlling the hybrid electric vehicle to execute the work flow of canceling low-speed pure electric, canceling the upper limit of the engine, and canceling the upper limit of the motor on the basis of economic operation.

[0114] It should be noted that, in the embodiment of the present invention, the low-power mode refers to the engine driving the motor to quickly generate electricity, so as to get rid of the low-power state, so that the motor has the ability to adjust the working range of the engine again, thereby ensuring the economy of the entire vehicle. .

[0115] In this embodiment, as shown in FIG. 6, the control method of the hybrid electric vehicle when the hybrid electric vehicle is operating in an economical manner includes the following steps:

[0116] S401. Acquire current vehicle speed information of the hybrid electric vehicle, and compare the current vehicle speed with a set upper and lower vehicle speed threshold v_upFor example, 30km/h, for example 15km/h are compared to determine the interval of ν value.

[0117] S402, determine VupWv, go to step S403o

[0118] S403, when it is determined that the torque demand of the entire vehicle is greater than the torque upper limit curve as shown in FIG. 7, go to step S404. [0119] S404, determine whether the power system of the hybrid electric vehicle is faulty, and if so, perform step S406 ; If not, go to step S405o

[0120] S405: If the power system has no fault, the engine is controlled to output according to the torque upper limit curve, and the remaining torque demand is supplemented by the motor, that is, when the hybrid electric vehicle is operating in an economical manner, if the hybrid electric vehicle's speed is greater than or equal to the third speed For example, when the threshold is 30km/h, when the vehicle torque demand of the hybrid electric vehicle is greater than the preset torque upper limit curve of the engine, the controller controls the engine to use the preset torque upper limit curve for torque output, and controls the electric motor to make up the torque. [0121] S406: If a fault occurs in the power system, fault processing is performed.

[0122] S407: When it is determined that the torque demand of the whole vehicle is less than the lower limit curve of torque as shown in FIG. 7, step S408 is entered.

[0123] S408. Determine whether the power system of the hybrid electric vehicle is faulty, if yes, execute step S410; if not, execute step S409.

[0124] S409: If the power system has no fault, the engine will output according to the lower torque limit curve, and the excess power will be used for motor power generation, that is, when the hybrid electric vehicle is operating in an economical manner, if the hybrid electric vehicle speed is greater than or equal to the third speed For example, when the threshold is 30km/h, when the vehicle torque demand of the hybrid electric vehicle is less than the preset torque lower limit curve of the engine, the controller controls the engine to output torque according to the preset torque lower limit curve, and controls the motor to generate electricity.

[0125] S410: If a fault occurs in the power system, fault processing is performed.

[0126] S411, it is determined that the torque demand of the whole vehicle is between the upper and lower limit curves of the torque as shown in FIG. 7, and the step is entered

S412o

[0127] S412: Determine whether the power system of the hybrid electric vehicle is faulty, if yes, perform step S414; if

No, go to step S413o

[0128] S413, the engine preferentially meets the torque requirement of the whole vehicle, and outputs a part of the torque for power generation. When h, when the vehicle torque demand of the hybrid electric vehicle is less than or equal to the engine's preset torque upper limit curve and greater than or equal to the engine's preset torque lower limit curve, the controller controls the engine to meet the vehicle torque demand for torque output, and controls the motor to perform torque output. Power generation. Among them, the principle of power generation follows the curve relationship between the generated power and the S0C value as shown in Figure 8, and the following two prerequisites must be met at the same time: 1The generated torque converted to the motor end does not exceed Tm^; 2The total output torque of the engine does not exceed the figure. In the torque upper limit curve shown in 7, if the engine torque calculated from the power generation curve exceeds any of the above two conditions, the above two conditions are used as the upper limit to jointly restrict the part of the engine torque used for power generation.

[0129] S414: If a fault occurs in the power system, fault processing is performed.

[0130] S415, determine v_up>v>v_dom, Go to step S416.

[0131] S416: Determine whether the power system of the hybrid electric vehicle is faulty, if yes, execute step S418; if not, execute step S417.

[0132] S417: If the power system is not faulty, the power system is controlled according to the original strategy workflow, that is, the original motor is driven alone and still runs in this mode, and if the original motor assists the engine to drive or generate electricity, it still runs in this mode.

[0133] S418: If a fault occurs in the power system, fault processing is performed.

[0134] S419: Determine vWvd. ^, go to step S420.

[0135] S420, judge whether the power system of the hybrid electric vehicle is faulty, if yes, execute step S422; if not, execute step S42L·

[0136] S421, if the power system has no fault, the motor is driven alone and the engine is turned off, that is, when the hybrid vehicle is operating in an economical manner, if the vehicle speed of the hybrid vehicle is less than or equal to the second speed threshold, for example, 15km/h, The controller controls the pure electric driving of the hybrid electric vehicle, that is, the pure electric operation of the hybrid electric vehicle.

[0137] S422: If a fault occurs in the power system, fault processing is performed.

[0138] In this embodiment, as shown in FIG. 9, the control method of the hybrid electric vehicle when the hybrid electric vehicle is running in a low-electricity mode includes the following steps:

[0139] S501. Obtain shift mode information, and determine the current execution gear of the hybrid electric vehicle.

[0140] S502, when it is determined that the hybrid electric vehicle executes the non-P gear, go to step S503o

[0141] S503, it is determined that the vehicle torque demand is greater than the torque upper limit curve as shown in FIG. 7, and step S504o is entered.

[0142] S504, determine whether the power system of the hybrid electric vehicle is faulty, if yes, execute step S506; if not, execute step S505.

[0143] S505: If the power system has no fault, the engine will output according to the torque upper limit curve, and the remaining torque demand will be supplemented by the motor. That is to say, when the hybrid electric vehicle is running in low-electricity mode, if the current gear of the hybrid electric vehicle is not In P gear, when the vehicle torque demand of the hybrid electric vehicle is greater than the preset torque upper limit curve of the engine, the controller controls the engine to output torque according to the preset torque upper limit curve, and controls the motor to make up the torque.

[0144] S506: If a failure occurs in the power system, perform failure processing.

[0145] S507: When it is determined that the torque demand of the entire vehicle is less than the torque lower limit curve as shown in FIG. 7, step S508 is entered.

[0146] S508, determine whether the power system of the hybrid electric vehicle is faulty, if yes, execute step S510; if not, execute step S509.

[0147] S509, if the power system is not faulty, the engine will output according to the lower torque limit curve, and the excess power will be used for electric power generation. That is to say, when the hybrid electric vehicle is running in low-electricity mode, if the current gear of the hybrid electric vehicle is not In P gear, when the vehicle torque demand of the hybrid electric vehicle is less than the preset torque lower limit curve of the engine, the controller controls the engine to output torque according to the preset torque lower limit curve and controls the motor to generate electricity.

[0148] S510: If a failure occurs in the power system, perform failure processing.

[0149] S511. Determine that the torque demand of the vehicle is between the upper and lower limit curves of the torque as shown in FIG. 7, and proceed to step

S512o

[0150] S512, judge whether the power system of the hybrid electric vehicle is faulty, if yes, execute step S514; if not, execute step S513.

[0151] S513, the engine preferentially meets the torque requirements of the entire vehicle, and outputs a part of the torque for power generation. When the vehicle torque demand of the hybrid electric vehicle is less than or equal to the preset torque upper limit curve of the engine and greater than or equal to the preset torque lower limit curve of the engine, the controller controls the engine to meet the vehicle torque demand for torque output, and controls the motor to generate electricity. Among them, the power generation principle follows the curve relationship between the generated power and the S0C value as shown in Figure 8, and the following two prerequisites must be met at the same time: 1 The generated torque converted to the motor end does not exceed Tm_fflax 2The total output torque of the engine does not exceed the torque upper limit curve shown in Figure 7. If the engine torque calculated from the power generation curve exceeds any of the above two conditions, the above two conditions shall be used as the upper limit for joint restriction. The part of the engine torque used to generate electricity.

[0152] S514: If a failure occurs in the power system, perform failure processing.

[0153] S515, when it is determined that the hybrid electric vehicle executes the P gear, go to step S516o

[0154] S516, execute the P gear idle start-stop strategy, that is, when the hybrid electric vehicle is running in low power mode, if the current gear of the hybrid electric vehicle is in the P gear, the controller controls the hybrid electric vehicle to enter the idle start-stop Mode, in this mode, when the hybrid electric vehicle meets the idle start and stop conditions, the engine stops.

[0155] When the HEV-eco mode drives the hybrid electric vehicle to run, the motor and the engine cooperate with each other to improve energy utilization. The general direction is that when the vehicle is working in the non-economic area of the engine, the use ratio of the motor is greatly increased. When the whole vehicle is working in the engine economic zone, the engine will generate a part of the electricity to charge the battery, and the lower the electricity, the higher the generating power. At the same time, the entire strategy of this mode limits the output power of the motor to a short term to avoid long periods. Time and high-power use of electricity ensures that the battery power is always maintained at a high level, prompting the motor to always have electrical energy to adjust the engine to work in a high-efficiency area, so that the final effect is to reduce the fuel consumption of hybrid drive as much as possible , To ensure economic performance and emission performance. When the whole vehicle needs a large load output, the electric motor can assist the engine to drive together, and the power performance is greatly improved compared with the EV mode. This mode can be used when the user needs to travel long distances and wants to reduce fuel consumption as much as possible.

[0156] In still another embodiment of the present invention, as shown in FIG. 10, the control method of the hybrid electric vehicle when the hybrid electric vehicle is running in the hybrid sport mode includes the following steps:

[0157] S601. Acquire EV mode key switch information, and determine whether to manually switch the EV mode, if yes, go to step S602 or step S603; if not, go to step S606.

[0158] S602. After receiving the EV mode button switch operation, compare the current SOC value of the power battery with the set SOC upper threshold SOC®, such as 30%, to determine whether the SOCup W SOC is satisfied, and if so, proceed to step S603; if not, go to step S605o

[0159] S603: Compare the current vehicle speed with a set vehicle speed threshold, such as 150km/h, that is, the maximum vehicle speed that allows the HEV mode to be switched to the EV mode, and determine whether the VW Vmax is satisfied, and if so, go to step S604; if not, then Advance

Go to step S605o

[0160] S604: Control the hybrid electric vehicle to switch to the EV-s mode and execute the corresponding power system control strategy.

[0161] That is, when the hybrid electric vehicle is in the hybrid sports mode, after the controller receives the switching instruction to switch to the pure electric sports mode, if it is determined that the SOC of the power battery is greater than or equal to the second power threshold, for example, 30%, And when the current vehicle speed of the hybrid electric vehicle is less than or equal to the first speed threshold, for example, 150km/h, the controller controls the hybrid electric vehicle to switch to a pure electric sport mode.

[0162] S605, the hybrid electric vehicle keeps running in the HEV-s mode.

[0163] S606, after receiving the no-EV mode key switch operation, obtain eco mode key switch information, and determine whether to manually switch the eco mode, if yes, go to step S607; if not, go to step S608.

[0164] S607, receiving the eco mode button switching operation, control the hybrid electric vehicle to switch to the HEV-eco mode and execute the corresponding power system control strategy.

[0165] S608: When the switch operation of the non-eco mode button is received, the working mode of the hybrid electric vehicle is not switched, the shift mode information is acquired, and the current execution gear of the hybrid electric vehicle is determined.

[0166] S609, when it is determined that the hybrid electric vehicle executes the P gear, go to step S610.

[0167] S610, execute the P gear idle start-stop strategy, that is, when the hybrid electric vehicle is in the hybrid sports mode, if the current gear of the hybrid electric vehicle is in the P gear, the controller controls the hybrid electric vehicle to enter the idle start-stop mode.

[0168] S611, when it is determined that the hybrid electric vehicle executes the non-P gear, go to step S612o

[0169] S612, compare the vehicle demanded torque with the engine peak torque, and determine whether the vehicle demanded torque>the engine peak torque is met, if yes, execute step S613; if not, execute step S614.

[0170] S613, the engine outputs according to the peak torque, and the remaining torque demand is supplemented by the motor. When the motor is limited by the current capacity of the motor or the power battery, it is driven according to the current maximum capacity of the motor and the power battery. That is to say, when the hybrid electric vehicle is in the hybrid sports mode, if the current gear of the hybrid electric vehicle is in the non-P gear, among which, when the vehicle torque demand of the hybrid electric vehicle is greater than the preset peak torque of the engine, control The engine controls the engine to output torque according to the preset peak torque, and controls the motor to make up the torque.

[0171] S614, the engine preferentially meets the torque requirement of the whole vehicle, and outputs a part of the torque for power generation, that is, when the hybrid electric vehicle is in the hybrid sports mode, if the current gear of the hybrid electric vehicle is in the non-P gear, When the vehicle torque demand of the hybrid electric vehicle is less than or equal to the preset peak torque of the engine, the controller controls the engine to meet the vehicle torque demand for torque output, and controls the motor to generate electricity. Among them, the power generation principle follows the corresponding curve relationship between the generated power and the SOC value as shown in Figure 8, and the following two prerequisites must be met at the same time: 1 The generated torque converted to the motor end does not exceed Ding._!£ 2The total output torque of the engine does not exceed the peak engine torque as shown in Figure 7. If the engine torque calculated from the power generation curve exceeds any of the above two conditions, the above two conditions shall be used as the upper limit for joint restriction. The part of the engine torque used to generate electricity.

[0172] When driving a hybrid vehicle in HEV-S mode, when the shift mode is non-P gear, the engine is always in the starting state. Only when the shift mode is P gear and the P gear idle start-stop conditions are met, The engine will stall. The entire strategy of the HEV-S mode no longer limits the maximum output torque and power of the engine and motor, and can exert the maximum driving capacity of the power system. It is the best power performance among the four driving modes, but due to the fact that the engine is driving It runs all the time, either in conjunction with the motor or driving the sideband motor to generate electricity (when the power of the power battery is below a certain value), so the fuel consumption is relatively high, and the economic performance cannot be guaranteed. The HEV-s mode is suitable for users who have high requirements on driving dynamics, and can have sufficient power equivalent to large-displacement luxury fuel vehicles, and maximize the user's acceleration pleasure.

[0173] In the embodiment of the present invention, four different working modes of EV-eco, EV-s, HEV-eco, and HEV-s can be obtained by switching the four buttons of EV, HEV, eco, and Sport, according to The vehicle dynamics and economy have different definitions of the four working modes, and the focus of the driving strategy of the power system is different. In addition, the power system of hybrid electric vehicles adopts parallel mode instead of series or hybrid connection. In addition, the engine start point has been optimized in the driving strategy, the vehicle speed judgment point has been increased, the slope judgment has been added, and the demand power judgment has been cancelled. In the economic strategy of HEV-eco mode, the engine working area is limited between the upper and lower torque curves, and the generating power adopts the dynamic change curve with the S0C value as the independent variable.

[0174] According to the control method of the hybrid electric vehicle of the embodiment of the present invention, a variety of selectable working modes can meet the user's driving needs under different working conditions, which can meet the electricity-only demand of urban working conditions, and can meet The dynamic requirements of suburban working conditions can truly achieve the driving of the whole vehicle to be guided by the user's subjective operation intentions, and to improve driving pleasure. Among them, the control system of the hybrid electric vehicle adopts the parallel mode. Compared with the multi-step energy conversion of the series mode, it can effectively improve the energy utilization rate. At the same time, the parallel structure is relatively simple, avoiding the cumbersome ECVT matching of the hybrid mode, and reducing the problems caused by poor matching. The risk of irregularities. In addition, the optimization of the starting point of the engine in the driving strategy avoids the premature and over-frequency start of the engine, which can effectively reduce the starting noise, increase the life of the starting system and the risk of frequent low-voltage power reduction due to frequent starting, and ensure the normal operation of other low-voltage electrical equipment At the same time, the engine working area is optimized to ensure that the engine always works in the high-efficiency area, and the power generation is optimized to ensure a higher power balance point during driving, which is conducive to the economic strategy of the entire vehicle most of the time , Can effectively reduce fuel consumption and reduce emissions. In addition, this control method can ensure the power and driving range of the vehicle's pure electric operation, avoid long-term high-power power consumption on the premise of meeting the power requirements of the vehicle to improve power efficiency, and also avoid frequent engine start-ups. Stop phenomenon, thereby extending the life of the starter, reducing driving noise, and improving driving comfort.

[0175] Any process or method description described in the flowchart or described in other ways herein can be understood to mean a module of code including one or more executable instructions for implementing specific logical functions or steps of a process, Fragments or parts, and the scope of the preferred embodiments of the present invention includes additional implementations, which may not be in the order shown or discussed, including the functions involved in a substantially simultaneous manner or in a reverse order according to the functions involved. This should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0176] The logic and/or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequence table of executable instructions for realizing logic functions, and can be embodied in any computer readable In the medium, for use by an instruction execution system, device, or device (such as a computer-based system, a system including a processor, or other systems that can fetch instructions from the instruction execution system, device, or device and execute the instructions), or execute in combination with these instructions System, device or equipment. For this purpose, a computer-readable medium may be any device that can contain, store, communicate, propagate, or transmit a program for use by the instruction execution system, apparatus, or device or in combination with these instruction execution systems, apparatus, or devices. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections (electronic devices) with one or more wiring, portable computer disk cases (magnetic devices), random access memory (RAM), Read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), optical fiber device, and portable CD-ROM read-only memory (CDR0M)_oIn addition, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because it can be used, for example, by optically scanning the paper or other media, and then editing, interpreting, or other suitable media if necessary. The program is processed in a way to obtain the program electronically and then stored in the computer memory.

[0177] It should be understood that each part of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be stored in a memory and executed by software executed by a suitable instruction execution system.

Or firmware to achieve. For example, if it is implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of the following technologies known in the art: Discrete logic circuits, application-specific integrated circuits with suitable combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0178] A person of ordinary skill in the art can understand that all or part of the steps carried in the method of the foregoing embodiments can be implemented by a program instructing related hardware to complete, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0179] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, or each unit may exist alone physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or software functional modules. If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0180] The aforementioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

[0181] In this description, descriptions with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean the description in conjunction with this embodiment or example Specific features, structures, materials or characteristics are included in at least one embodiment or example of the present invention. In this context, the schematic representations of the above-mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0182] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it will be understood that various changes can be made to these embodiments without departing from the principle and spirit of the present invention. Modifications, substitutions and variations, the scope of the present invention is defined by the appended claims and their equivalents.