Method for managing a system for supplying a vehicle electrical system with electrical energy

MANAGEMENT PROCESS OF A SYSTEM TO SUPPLY NETWORK BOARD A VEHICLE INTO ELECTRICAL ENERGY

[Oooi] The present invention claims priority of French application 1259670 filed Oct. 10, 2012, the content (text, drawings and claims) is incorporated herein by reference.

[OOo2] The present invention relates generally to a method of managing a system for supplying an onboard network of a vehicle into electrical energy.

[OOO3] Figure 1 illustrates a known system for feeding an onboard network of a vehicle into electrical energy. The system 1 comprises a generator 3 (for example, an alternator, an alternator or a DC / DC converter (DC / DC)), an electrical energy storage device of example 5 by a 12V battery, a board network 7 including the all electrical and electronic components of the vehicle, a set 9 including a switch K and a DC / DC converter 11, and an additional electrical energy storer 13, which is connected to the assembly 9 and the DC / DC converter 11.

[Ooo4] The operation of the system 1 can be divided into two phases:

[Ooo5] Phase 1: the switch K (MOS, electromechanical relay, diode) is closed. The generator 3 is driven by a vehicle engine and generates electric energy. This electrical energy to recharge the battery 5, to power all electrical and electronic components of board 7 network and charge the additional storage device 13 via the DC / DC converter 11 integrated across 9.

[Ooo6] Phase 2: the switch K is open. The generator 3 and the battery 5 are isolated from other organs by switch K. The generator 3 may be trained and produce electrical energy to recharge the battery 5 or be shut down and therefore the battery 5 imposes its terminal voltage of the generator 3. The DC / DC 1 1 all the Additional stocker 9 and 13 used to provide electrical energy to the edge 7 network while ensuring a satisfactory voltage onboard network needs from the edge of the network (eg 13.5V). Then when the additional storage device 13 no longer has enough energy, the DC / DC 1 1 integrated in all nine stops working, the switch K is closed and the generator 3 and the battery 5 becomes the source main energy to the edge 7 network.

[Ooo7] These two phases are repeated periodically.

[Ooo8] However, during the transition from Phase 2 to Phase 1, the stop of the DC / DC 1 1 all 9 can generate a voltage drop seen by the board network 7 causing such , decreased intensity of fires or reset some vehicle computers. This is illustrated in Figures 2A and 2B.

[Ooo9] For example, assume that the edge network represents a power consumption of 50A.

[Ooi o] The switch K is off, isolating the generator 3 and 5 of the battery DC / DC 1 1 additional stocker 13 and the onboard network.

[Ooi i] 3 When the generator is off, the voltage of the battery 5 is imposed on the generator terminals 3. The DC / DC 1 1 and 13 provide the additional storage device 50A to the onboard network 7 while regulating the voltage terminal board network (eg 13.5V). [0012] When the DC / DC 1 converter 1 stops operating, the switch K closes and the consumption of the network edge 7 is therefore directly imposed on the generator 3 and the battery 5. The generator 3 and the battery 5 therefore see this 50A consumption imposed as a strong call current. The battery provides 5 temporarily need this energy to the network before the generator 7 3 resumes hand and become the main energy source. When the supply of energy from the battery 5 following the judgment of the DC / DC converter 1 1 a voltage drop can be imposed on the edge 7 network (Figure 2B).

[0013] This voltage drop could deprive energy safe function of the vehicle.

[0014] An object of the present invention is to meet the drawbacks mentioned above and in particular, to propose a method for managing the power system of a vehicle electrical system with electrical energy for supplying a stable voltage which n 'not impede safe function of the vehicle.

[0015] To this end a first aspect of the invention relates to a method of managing a system for supplying an onboard network of a vehicle into electrical energy, the system comprising:

• an onboard network including electrical or electronic elements of the vehicle;

• a storer of electric power;

• electric power generator connected to the storekeeper of electric power;

• an additional electric power storage device; and

• an assembly comprising a switch and a DC / DC converter, all being connected to the storekeeper of electric power, the electric power generator and the onboard network when the switch is closed, and connected to additional storer of electric power and the onboard network when the switch is open; [0016] the method comprising the steps of:

• supplying the electrical energy onboard network via the additional electrical energy storage device and the DC / DC converter when the switch is open;

• regulating the electric energy generator for supplying a voltage less than that imposed by the DC / DC converter and higher than a voltage of the electric energy storage device;

• closing the switch so that the DC / DC converter requires a voltage to upper edge network to that of the storage device electric power and an electric power generator;

• applying to the edge of a network voltage of the electric power generator superior to the DC / DC converter to power the on-board network into electrical energy through the electrical power generator; and

• disabling the DC / DC converter.

[0017] Such a process management avoids a voltage drop that occurs when the deactivation of the DC / DC converter and the additional storage device, and helps provide a stable voltage which does not impede the safe function of the vehicle.

[Ooi 8] Very advantageously, during the step of applying a voltage of the electric power generator superior to the DC / DC converter, the voltage of the electric power generator is increased to exceed that of DC / DC converter. [0019] A particularly advantageous embodiment consists in that the voltage of the electric power generator is increased gradually.

[0020] Advantageously, during the step of applying a voltage of the electric power generator superior to the DC / DC converter, the voltage of the DC / DC converter is decreased to fall below that of electric power generator.

[0021] Advantageously, the voltage of the DC / DC converter is gradually reduced.

[0022] Very advantageously, in the step of feeding the electrical energy onboard network via the additional electrical energy storage device and the DC / DC converter when the switch is opened, the generator electric power is shut down and restarted when the step of controlling the electric power generator for supplying a voltage less than that imposed by the DC / DC converter and higher than a voltage of the electrical energy storage.

[0023] Very advantageously, in the step of feeding the electrical energy onboard network via the additional electrical energy storage device and the DC / DC converter when the switch is opened, the generator electrical energy is activated and controlled to provide a voltage lower than that imposed by the DC / DC converter.

[0024] Very advantageously, the electric power generator is controlled to provide a voltage lower than that imposed by the DC / DC converter and higher than a voltage of the electric energy storage device when the level of discharge of the additional storage device of electric power reaches a predetermined value.

[0025] According to a second aspect, the present invention relates to a system for supplying an onboard network of a vehicle into electrical energy comprising: • an onboard network including electrical or electronic elements of the vehicle;

• a storer of electric power;

• electric power generator connected to the storekeeper of electric power;

• an additional electric power storage device;

• an assembly comprising a switch and a DC / DC converter, the assembly being connected to the storage device of electric power, the electric power generator and the edge of network in a manner to supply the vehicle electrical system with electrical energy by through the power generator when the switch is closed, and connected to the additional storage device of electricity and on-board system in a way to power the onboard network in electric power through the additional storage device electric power and DC / DC converter when the switch is open;

[0026] characterized in that it further comprises a controller configured to regulate the electric power generator for supplying a voltage less than that imposed by the DC / DC converter and higher than a voltage of the electric energy storage when the switch is open, and for supplying on-board system voltage of the electric power generator superior to the DC / DC converter when the switch is closed.

[0027] According to a third aspect, the present invention relates to a motor vehicle comprising the system as defined above.

[0028] Other features and advantages of the present invention appear more clearly on reading the following detailed description an embodiment of the invention given by way of non-limiting example and illustrated by the accompanying drawings, wherein:

• Figure 1 illustrates a system for supplying an onboard network of a vehicle with electric power of the prior art; · Figures 2A and 2B illustrate a drop in voltage seen by the vehicle electrical system due to the deactivation of the DC / DC converter of the system illustrated in Figure 1;

• Figure 3 illustrates a system for supplying an onboard network of a vehicle with electric energy according to the present invention; and

• Figures 4A and 4B illustrate the improvement provided by the system for supplying an onboard network of a vehicle with electric power of the present invention and of the system management method. [0029] Figure 3 illustrates a system 100 for supplying an onboard network of a vehicle with electric energy according to the present invention. The system 100 comprises an electric power generator 103 such as an alternator, an alternator or a DC / DC converter (for example, a converter DC / DC or a DC voltage converter), an electrical energy storer 105 such as an electrochemical battery (12V for example), an onboard network 107 including electric or electronic elements of the vehicle, an assembly 109 comprising a switch K and a DC / DC converter (DC / DC) 1 1 1 (by example, a current converter DC / DC or a DC voltage converter), an additional electrical storer énergie 1 13 as a supercapacitor or a battery and a control device 1. 15 [0030] The power generator 103 is connected to the negative terminal of the battery 105 and the positive terminal of the battery 105 is connected to the switch K M. The mass is electrically connected on one side to the negative terminal of the battery 105 (and the electric power generator 103) and the other side in series with the electrical system 107. the DC / DC converter 1 1 1 is electrically connected on one side between the switch K and the edge of network 107 and it is electrically connected across the additional storer electrical energy storer 1 13. the additional electrical energy 1 13 is also electrically connected to the earth M. the control device 1 15 is connected to the assembly 109, the electric power generator 103, the storer of electrical energy storer 105 and the additional electrical énergie 1. 13

[0031] The switch K can be, for example, an MOS switch, an electromechanical relay or a diode. [0032] The power generator 103 is, for example, adapted to be driven by an engine of the vehicle to generate electric energy. This electrical energy to recharge the electrical energy storage device 105, to supply all the electrical and electronic components of board network 107 and charge the additional storekeeper January 13 via the DC / DC converter 1 1 1.

[0033] The control device 1 15 is adapted to close the switch K for feeding the edge of network 107 into electrical energy via the electric energy storage device 105 or the electric power generator 103 and to recharge the additional storage device 1 13. the controller 1 15 is also able to enable and disable the DC / DC converter 1 1 1 and open the switch K to power the onboard network 107 into electrical energy through the additional storage device electrical énergie 1 13 and the DC / DC converter 1 1 1. [0034] The control device 1 15 is further configured to receive from the additional storekeeper January 13 a value of a discharge level of the Additional storekeeper January 13 and a voltage value applied by the DC / DC 1 1 1 on-board system 107. It is further configured to receive from the electrical energy storage device 105 a voltage value provided by the electrical energy storage device 105.

[0035] There is further configured to regulate the electric power generator 103 for supplying a voltage less than that imposed by the DC / DC converter 1 1 1 and greater than a voltage of the electric energy storage device 105 when the switch K is open.

[0036] It is configured to regulate the electric power generator 103 for supplying such a voltage when the discharge level of the additional storage device 1 13 reaches a predetermined value, e.g., 85%, or 90% or 95%. [0037] The control device 1 15 is further configured to enforce the edge of a network voltage of the electric power generator 103 higher than the DC / DC converter 1 1 1 when the switch K is closed.

[0038] The control device 1 15 is further configured to gradually increase the voltage of the electric power generator 103 is to exceed that of the DC / DC converter 1 1 1, and to gradually decrease the voltage of the DC / DC 1 1 1 to fall below that of the electric power generator 103.

[0039] A system management method 100 according to the present invention will now be described (Figures 4A and 4B).

[0040] In Phase 2 (described above), switch K is set in the open position and the electric power generator 103 and the storekeeper Electric Power 105 are isolated from other organs by switch K.

[0041] The electric power generator 103 is driven to produce a voltage lower than the DC / DC converter 1 1 1, or stopped. [0042] The DC / DC converter 1 1 1 of the assembly 109 and the additional storage device 1 13 provide electrical energy to the onboard network 107 while ensuring a satisfactory voltage vehicle electrical system to the needs of on-board network ( eg 13.5V).

[0043] When one wants to use the electric power generator 103 or the electrical energy storage device 105 to provide electrical power to the onboard network 107 or when the discharge level of the Additional storekeeper January 13 reaches a predetermined value for example, 85% or 90% or 95%, the switch K is kept in an open position, the electric power generator 103 is activated if required and is controlled to provide a voltage lower than that imposed to the network edge 107 by the DC / DC converter 1 1 1 and greater than the voltage of the electric energy storage device 105.

[0044] The switch K is then closed and the DC / DC 1 1 1 imposes its voltage at the edge of network 107 because this voltage is greater than the electrical energy storage device 105 and that produced by the generator 103 electrical energy.

[0045] A voltage of the electric power generator 103 higher than the DC / DC converter 1 1 1 is then applied to the onboard network 107, for example, by increasing the voltage of the electric power generator 103 to exceed that of the DC / DC converter 1 1 1 or decreasing the voltage of the DC / DC converter 1 1 1 to fall below that of the electric power generator 103. the power generator 103 becomes the source 'primary energy for the edge network 107. [0046] The DC / DC converter 1 1 1 can be turned off when the voltage of the electric power generator 103 becomes higher than that of the DC / DC converter 1 1 1. Additional storekeeper January 13 no longer supplies power to the onboard network 107. [0047] The voltage of the electric power generator 103 is, for example, and gradually increased the voltage of the DC / DC converter, for example, less gradually.

[0048] With the present invention, the voltage drop imposed on the edge of the network and due to the deactivation of the DC / DC converter is removed so that the quality of the onboard network is improved, a stable voltage is always supplied to board network and continuous operation of the security functions of the vehicle is insured.

[0049] It is understood that various modifications and / or improvements obvious to those skilled in the art can be made to various embodiments of the invention described herein without exceeding the scope of the invention defined by the appended claims.