System and method for the controlled transfer of energy in networks comprising sectors that are powered by two different batteries

ES 2 192 467 A1

DESCRIPTION

System and method for a controlled energy transfer in networks with sectors fed from two different batteries.

Field of the invention

The present invention concerns a system and a method applied to provide a controlled energy transfer in networks with several sectors fed from two different batteries, applicable to motor vehicles, with an architecture comprising a first battery B1 and a second battery B2, in operating at differentiated voltage levels (Dual Voltage or DV system) that can be charged from a generator G, both batteries B1 being equipped, B2 of a control module for its state of charge and health SOC, SOH. Batteries B1, B2 feed respective networks where various loads are included, a first one comprising at least one starting device and a second one that integrates security and supervision or waiting modules. The energy is distributed to said networks from the aforementioned batteries B1, B2, from several distribution boxes that include a management microcontroller, and the system integrates a communications bus for a global management of the same, centralized or decentralized. In general, there are several of said power distribution boxes located in different parts of the vehicle.

Such DV systems typically comprise a first 14 V network used to power low consumption loads, for example for lighting and supply of control signals, capable of being fed in turn, from the second network at a higher voltage, typically 42V, through an electrical DC / DC converter or from a first battery B1. For its part, said second 42 V network is used to supply high consumption loads such as the starter motor, heating system, control of electromagnetic valves, motors, such as those of the window regulators, devices for position adjustment, fans, etc. and is powered from a generator G (vehicle alternator) or from a second battery B2.

The invention is inscribed by the above within the architectures implemented in the automotive sector to achieve a sectorization of power, according to the principle of which a series of zones are defined in the vehicle in each of which there is an "intelligent" node or power distribution box with a microcontroller and management programs implemented on the basis of it, which locally controls the loads and switches and detectors, sending and receiving information through a data bus, which allows a great reduction not only in the number of cables but also in their length, without forgetting the decrease in the number of cables that pass from one area of ​​the vehicle to another, whose parameter has a significant impact on the ease of wiring assembly.

The invention provides this field with a new functionality implemented through a method that comprises algorithms executed by the aforementioned microcontrollers of said power distribution boxes that allow the energy available at any time in a system with at least one to be managed in a highly optimized way. least two batteries B1 and B2 with a permanent control of their state of health and charge, as well as the energy flows supplied by each of said batteries B1, B2.

Background of the invention

GB-A-2 302 622 discloses a dual battery vehicle management system comprising: a first battery B1 intended to supply a series of loads of a first service network that is connected to one of the terminals of said battery B1, to which a generator is also connected; a second battery B2 destined to power a second network essentially dedicated to starting functions and a switch governed by a control unit or module that, depending on the state of charge of both batteries B1 and B2 and the demands of the charges of said respective networks, it enables the passage of current between batteries B1, B2 and corresponding networks, in any of the directions, always giving priority to the starting functions.

Other patents such as DE-A-196 45 944 A1 and US-A-6,232,674 describe architectures and systems intended for the same purpose explained and that provide similar features.

DV systems for motor vehicles, in the field of which the invention finds a particular application, are described in numerous patent documents and patent applications, and the following may be cited: US 5 334 926, US

232 674, EP 337155, EP 539982, EP 1033804, WO 99/22434 and WO 00/76812.

Patent application GB-A-2 342 515 describes a DV architecture with two networks fed from batteries B1, B2, for motor vehicles, where the use is proposed, in addition to a conventional DC / DC converter, generally unidirectional. , to supply the low voltage network from the higher voltage network, a second bidirectional converter for, from a control of the state of charge of the two batteries B1 and B2, be able to adjust the power flows between its inputs / outputs. Said second DC / DC converter is used when, in addition to normal operation (feeding the lower voltage level network from the network to a higher voltage level), the low voltage network is fed from the battery connected to the higher voltage branch. , the higher voltage network is fed from the two batteries B1, B2 or when the battery B1, which feeds the low voltage branch, is charged from the higher voltage network.

Patent US-B1-6232674 refers to a control device for mounting in a motor vehicle with at least two batteries that can be charged from a generator and supply various loads. The control device is sandwiched between the two batteries and includes a mains supply element, a microcontroller associated with a communication bus, a DC / DC converter and a final short-circuit verification stage. Based on various information sent to said microcontroller, relative to the energy supply requirements of the re2

ES 2 192 467 A1 des, the electrical control system establishes a connection between the two batteries and after disconnection it enters a standby mode.

International application ES00 / 00393, of the applicant himself describes a modular set connected to a battery for monitoring its status and protection, comprising in a housing that can be attached to the terminals of said battery: a first module applied to a disconnection of the energy supply from said battery, a second electronic module applied to a dynamic measurement of the state of health (SOH) and state of charge (SOC) of the battery and a third electronic module destined to a control and management of all or part of the loads that power said battery.

Patent applications WO-A-95/13470 and EP-A-0892486 describe DV electrical current distribution systems with the participation of DC / DC converters, generally unidirectional.

The international application ES00 / 00173 of the applicant himself concerns a dual voltage electrical distribution system, where the integration of DC / DC converters in power distribution boxes, as referred to at the beginning, is proposed, having provided that the microcontroller included in these boxes, it controls both the operation of the converter and the control signal flows and the flow of energy to the loads.

Although the architecture of the electrical power distribution system of the present invention is similar to that of the cited international application ES00 / 00173 and the batteries of said system include modules similar to that described in international application ES00 / 00393, the functionalities of the present invention cannot be achieved with these, or other referred antecedents.

Presentation of the invention

The present system was invented with an architecture such as the one referred to in the initial paragraph of this report, although the two aforementioned batteries B1 and B2 could be of the same voltage level, and implanted on a vehicle, such as a car, are characterized by additionally comprising a device for detecting a voltage level and / or polarity of an external power supply capable of being connected to at least one of the terminals of one of the two batteries B1 or B2, and controlled switching devices for routing said external energy flow towards one of said two batteries B1 or B2, predetermined. On the other hand, said power distribution boxes towards the loads, with a microcontroller, are interconnected with each other and connected to said control modules of the batteries B1, B2, in order to carry out permanent monitoring of the state of health and charge of said batteries. two batteries B1 and B2 and provide a controlled transfer of energy between them, at any time, even when the vehicle engine ignition key is closed, independent of consumption and to anticipate future demands.

According to a first aspect of the invention, the two batteries B1 and B2 have tension levels differentiated by Ex. 12 V and 36 V, respectively, and each of the aforementioned power distribution boxes includes a DC / DC converter, at least one of said DC / DC converters being bidirectional, and allowing said energy transfer from one to the other. of said batteries B1, B2, in any sense, follow the result of the aforementioned monitoring of the state of charge and health of the same.

In a preferred embodiment of the invention, there are three of the aforementioned power distribution boxes, one of them to feed loads from the front area of ​​the vehicle, a second to supply a central area of ​​the same, and a third to supply power to the rear of the vehicle. According to said preferred embodiment, a first of said boxes is fed from battery B1 at a lower voltage level and includes said bidirectional converter allowing loads to be fed to said first voltage level and to a second, higher voltage level. the two remaining power distribution boxes being connected to battery B2 at a higher voltage level and integrating a unidirectional converter that only enables the supply of power at said first, lower voltage level.

According to the invention, each of the B1, B2 batteries comprises a power disconnection device or BCO (Battery Cut Off) applied to the automatic disconnection of the corresponding B1, B2 battery from its network, in the event of an accident or by instructions received. from one of the microcontrollers of the distribution boxes or from the control module itself. To allow the carrying out of diagnostic tasks or repairs on the electrical networks and electronic systems of the vehicle, it has been foreseen to integrate a switch accessible by a user to enable or disable said BCO disconnection devices.

The invention also provides a method based on the use of the energy distribution system explained, a method characterized by permanent monitoring of the health (SOH) and charge (SOC) of each of said two batteries B1, B2 and at the same time the voltage or polarity of an external power supply capable of being connected to one of the terminals of one of said batteries B1, B2, and by an actuation by means of the aforementioned microcontrollers (either of the power distribution boxes or of the modules associated with each battery) to ensure an energy transfer between said two batteries B1, B2, at any desired time.

The system and method follow the invention, implemented in a DV architecture for a vehicle, such as the aforementioned and including control means, allow the following functions to be carried out:

a) 14 V power supply for safety and standby or alert functions (Stand-By). If necessary, the system will convert a power flow from 42 V to 14V even though the vehicle key is in the off position, thus reducing the chances of power interruption.

ES 2 192 467 A1 tion of the safety and Stand-By modules that are powered at 14V; Through the switches of the aforementioned BCO disconnection devices, the general disconnection of the system has been provided in the event of power loss that does not cause the fuse to blow (ohmic short-circuits, power devices such as faulty FETs, etc.);

b) automatic start-up from only the system implemented on the vehicle or internal, allowing the charging of the battery B2 of 36 V through the battery B1 itself, of 12 V in a controlled way; The system verified that the SOC / SOH of the 12 V battery B1 is correct, since otherwise said internal start-up would not be allowed; The discharge cycles of the 14V B1 battery were also controlled (eg X sec. every Y minutes) and to guarantee the efficiency of the 36 V battery charging it is also necessary to ensure that the 12 V battery does not supply power to unnecessary loads (by disconnecting the corresponding BCO disconnection devices from each of the batteries B1 and B2;

c) starting the vehicle with external assistance from another vehicle; The system will allow the connection of energy from an external source of both 14 V and 42 V, detecting which voltage level is automatically and transferring the energy to the appropriate B1 or B2 battery, in each case; To avoid connections between batteries of different voltages, a polarized connection system was used;

d) diagnostic or repair mode: when the vehicle is in a dealership or workshop for its electrical-electronic diagnosis or for its repair, the system has been provided with a switch that activates the BCOs in such a way as to avoid having You have to disassemble the terminal or separate the module associated with the battery, this switch also fulfilling the function of transport fuse;

It should be noted that despite the modifications implied by the system and method of the invention (making the BCOs play an auxiliary role in some cases), the disconnection functionality of both batteries B1 and B2 provided by the switches of the batteries was maintained. respective BCO disconnection devices in the event of a vehicle impact.

For a better understanding of the characteristics of the invention, it was described on the basis of an example of a possible execution illustrated in the attached drawing sheets, which should be considered merely illustrative and not limiting.

Brief explanation of the drawings

In these drawings:

Fig. 1 schematically shows an exemplary architecture of a practical implementation of the principles of the invention.

Fig. 2, details in a simplified way, a possible implementation of the polarized connection and / or with voltage detection, in the case of connection of the electrical power distribution system to an external supply source, allowing that whatever the nature of the same (vehicle at 14 V or 42 V) said connection and external power supply is directly managed by the system without any disturbance to the integrity of the same and essentially of its at least two batteries B1 and B2, in this example at different voltage levels 12 V and 36 V, respectively.

Detailed explanation of an example of implementation of the invention

In Fig. 1 an architecture for implementation of the system and method according to the invention can be seen. Said system comprises a first 12 V battery B1 and a second 36 V battery B2 that supply respective networks 17 (14 V) and 18 (42 V) according to a topical structure of "Dual Voltage" hereinafter DV. The aforementioned batteries B1 and B2 each have corresponding control units CB1 and CB2 that basically comprise a module 10, 11 for monitoring the SOC charge status and the SOH health status of the corresponding battery, a monitoring device 13, 14 of the batteries B1, B2 were disconnected from their respective networks 17, 18 and a block 15, 16 of fuses, of main hierarchy with respect to other fuses included in the networks that feed said batteries B1, B2. Each CB1, CB2 unit has an external switch 13a, 14b to act directly on those disconnection devices 13, 14, if necessary, avoiding the physical disconnection of the corresponding network terminal, linked to a battery terminal.

As shown in Fig. 1, the 12 V battery B1 feeds the 14 V network 17 through the CB1 control unit, which includes a series of security and standby or Stand-By modules (arrow on the left of Fig. starting from said network 17), which can remain powered even though the BCO device 13 disconnects the battery from its network 17. In this network 17 at a voltage of 14 V there were various resistive loads, generally lamps of various kinds and other low-consumption devices. Network 17 is connected to an SDN1 power distribution box or “smart” node (Smart Distribution Node) located in the engine compartment. The distribution box SDN1 houses a bidirectional DC / DC converter 25, to which the 14 V network 17 converges and which has an output connected to the second 42 V network 18, allowing for example. charging the 36 V battery, B2, through the 12 V battery B1, if necessary and in a controlled manner. The aforementioned bidirectional converter 25 has another output that links to an actuator module on loads or MAC from which two outputs are derived at 14 V and at 42 V that pass through a block of fuses FJI of a hierarchy lower than block 15 of the CB1 unit. As its name indicates in English, the SDN1 box includes a microcontroller 1, linked by a communication bus 19, such as a CAN bus, for example, with a microcontroller that has not been illustrated in such a way.

ES 2 192 467 A1 differentiated, in charge of said unit CB1. The microcontroller 1 of the SDN1 box acts on its MAC to conveniently manage the energy to be supplied to the various loads.

In Fig. 1 two other SDN2 and SDN3 boxes for energy or power distribution are shown, with similar components to those referred to when describing the SDN1 box, although the DC / DC converters 26 and 27 that they include are unidirectional since Said SDN2 and SDN3 boxes are connected to the 42V network 18, with which the only functionality of said DC / DC converters 26 and 27 is the supply of power to the 14V loads or to the network 17. The microcontrollers integrated in each of said boxes SDN2 and SDN3, respectively, have been indicated with 2 and 3.

It can be seen in Fig. 1 that in the 42 V network 18 there are at least two branches 18a, 18b with direct output to some power loads without passing through the respective MAC module of one of the SDN2 or SDN3 distribution boxes.

By means of the architecture explained and carrying out a permanent monitoring of the state of charge and health of the batteries B1, B2, as well as the power requirements of the different parts of the system, including some possible sources of supply (essentially for the start-up of the system). vehicle) and supervising the voltage or polarity of an external power supply that can be connected to one of the terminals of one of said batteries B1, B2, and by an actuation by means of microcontrollers of the SDN1, SDN2 or SDN3 boxes, a transfer of energy to the loads and between said two batteries B1, B2, at any desired moment, of perfectly controlled magnitude is ensured.

This allows:

a) powering the battery B1 from the battery B2, using the DC / DC converter 25 of the SDN1 box;

b) charge battery B2 (which has starting functions) from battery B1, also using the DC / DC converter 25 of the SDN1 box;

c) disconnect the networks 17, 18, maintaining a connection between the batteries B1, B2 using the disconnection devices 13,

14.

In Fig. 2 the solution adopted to ensure effective control over an external power source has been schematically detailed, for example in the case that a first vehicle, which has the system implemented according to the invention, must resort to a second one. vehicle, to aid in the starting task, making a connection between the electrical systems of both vehicles.

According to a preferred embodiment of the invention, a special terminal 30 has been provided, to which the connection must be made by an external battery. Said terminal 30 has associated a voltage or polarity detecting device 31 and the information thereof is managed, for example, by a microprocessor 32, with two outputs connected to respective power switches 33, 34, which in Fig. they have been schematized as power relays, appreciating their coils 33a, 34a and their switches 33b, 34b, although they could be implemented by means of a solid state semiconductor device or the like.

Through said power switches 33, 34 and depending on the voltage or polarity detected in the auxiliary terminal 30, a routing of the power of the external battery was established towards one or the other of the batteries B1 or B2, mentioned.

Having described the invention in a sufficient way to be able to be carried out by a technician in the field, it is sought to extend its object to those variations of detail, in particular the use of devices with equivalent functionality in different points of the architecture explained. that do not alter its essentiality which is summarized in its essential aspects in the following claims.