System for supplying power to consumers of an electric or hybrid vehicle and method for managing the power supply of a vehicle

Abstract

The invention relates to a power supply system (1) for equipment of an electric vehicle, comprising: - a battery (8) supplying an electric powertrain; - power switches (14, 16, 18) for connecting the battery (8) to the electric powertrain; - a DC-DC converter (4, 6) for the operating phase, for supplying an on-board network (50) during operating phases of the vehicle, connected at the input to the battery (8) and at the output to the on-board network (50); and - a DC-DC converter (2) for the inoperative phase, connected at the input to the battery (8) upstream of the power switches (14, 16, 18) and at the output to the on-board network (50), for supplying the vehicle in standby.

Description

Description Title of the invention: Electrical supply system for consumers of an electric or hybrid vehicle and method for managing the power supply of a vehicle

[0001] The present invention relates to the fields of electricity and the automotive industry, and more specifically concerns an electrical power supply system in an electric or hybrid electric vehicle, intended to power the vehicle's equipment.

[0002] Electric or hybrid electric vehicles are very often equipped with a lithium-ion battery or equivalent technology, capable of supplying the energy necessary for an electric motor allowing the traction or propulsion of the vehicle, in possible cooperation with a thermal engine. Such a battery is called high voltage because the maximum no-load voltage at its terminals is generally much higher than that of service batteries, usually of the order of 12V (volts). However, some service batteries deliver a voltage of the order of 48V, this value can also be the maximum no-load voltage of certain "high voltage" batteries.

[0003] In an electric or hybrid electric vehicle, the service battery, often lead-acid, is used to power the vehicle's on-board network to which the vehicle's computers and low-voltage consumers such as windshield wiper actuators, sensors, or small heating resistors are connected. Since the service battery is generally more stable than the high-voltage battery, it also guarantees the power supply of vehicle safety devices such as braking and steering systems, while the high-voltage battery, which discharges more quickly, is intended to power the vehicle's electric motor, and possibly other high-voltage equipment such as an air conditioning compressor. The electrical network to which this equipment is connected is called the vehicle's "high-voltage" network.

[0004] The service battery only needs to be changed every three to four years, and is therefore used to power at least the vehicle's consumers during long periods of inactivity, i.e. when the vehicle is stationary and switched off. It is then said to be "asleep" because in reality during these periods of inactivity, the vehicle's computers have modules that remain activated to monitor the vehicle's environment, such as an alarm, a computer's communication module to receive radio signals from an ignition key, or messages from a remote server via a network of wireless communication, for example, requiring the sending of maintenance data or software updates. This consumption of vehicles during periods of inactivity is also set to increase over time, particularly due to the entry of vehicles into the Internet of Things.

[0005] However, anti-pollution standards will ban lead-acid batteries, which are also heavy and bulky, which will require, for example, replacing them with small lithium-ion batteries, which are very expensive and will need to be recharged very often when the vehicle is not in use, in particular by waking it up to connect a direct current - direct current converter to the high-voltage battery, the converter allowing the small lithium-ion battery to be recharged. This solution is energy-intensive due to waking the vehicle and the procedures for checking the high-voltage network before recharging the small lithium-ion battery.

[0006] There is therefore a need to optimize the electrical architecture of an electric or hybrid electric vehicle, without a lead-acid service battery, ensuring the operation of the vehicle's safety equipment and making it possible to optimize the vehicle's energy consumption during long periods of disuse.

[0007] The present invention aims to remedy at least in part the drawbacks of the technique by providing an electrical power supply system for equipment of an electric or hybrid electric vehicle and a method for managing the power supply of the on-board network of a vehicle equipped with such an electrical power supply system, which make the power supply of the vehicle equipment more reliable, including in standby mode, while minimizing the consumption of the electrical power supply system.

[0008] To this end, the invention proposes a system for supplying electrical power to equipment of an electric or hybrid vehicle, comprising: - a battery, capable of providing the energy necessary for the operation of an electric powertrain of the vehicle, - power switches capable of connecting the battery to the vehicle's electric powertrain, - at least one direct current - direct current converter, called an operating converter, capable of supplying an on-board network of the vehicle during operating phases of the vehicle, the operating converter being connected at the input to a first set of battery cells and at the output to the on-board network of the vehicle, - a direct current - direct current converter, called a rest converter, connected on the one hand at the input to a second set of battery cells upstream of the power switches and on the other hand at the output to the vehicle's on-board network, the rest converter being intended to supply the vehicle when it is in standby mode, - an operating converter control unit, powered by the vehicle's on-board network, and - a rest converter control unit, powered by the vehicle's on-board network.

[0009] In the invention, the battery is capable of operating the electric powertrain, it is therefore a “high voltage” battery or traction battery, that is to say a battery of electric accumulators powering an inverter and an electric motor when the vehicle is running, unlike a service battery of the prior art. The battery in the invention can therefore also be understood as a propulsion battery depending on the electric motor used, this being an electric motor allowing the traction or propulsion of the vehicle, possibly in cooperation with another type of motor if the vehicle is hybrid, understood in the sense of “electric hybrid” in this application.

[0010] Furthermore, it should be noted that the terms "upstream" or "downstream" in this application refer to the relative position of electrical components or assemblies with respect to the direction of the current leaving the battery and heading towards the consumers of the vehicle. Thus, a first component is upstream of a second component if the current leaving the battery first passes through the first component and then the second component before returning to the traction battery, the latter being in discharge.

[0011] Thanks to the invention, the on-board network no longer needs to be powered by a service battery as in the prior art. Indeed, in the invention, whether the power switches are closed or open, the on-board network is powered either by the operating converter or by the rest converter.

[0012] More specifically, when the vehicle is in standby or "asleep" mode, the vehicle's computers are powered at least by the rest converter to allow them to receive, for example, activation messages only. For this purpose, the rest converter is connected upstream of the power switches, which allows it to always be powered by the second set of battery cells. It should indeed be noted that in the invention, the devices connected at the input to a set of battery cells are connected without an intermediate converter. In addition, since the control unit of the rest converter is powered by the on-board network directly at the output of the rest converter, its operation is secure.

[0013] When a vehicle supervision device, for example the vehicle's main computer, receives a message from an external server or a user request such as a request to unlock the vehicle, it reactivates, reactivates the other computer systems of the vehicle and the operating converter which in turn supplies the vehicle's on-board network during this entire phase where the supervision device is reactivated, called the operating phase. This may correspond to a driving phase of the vehicle or a "life on board" phase during which the vehicle is stopped but where a user can use, for example, a multimedia environment of the vehicle. The operating converter is connected to the battery upstream or downstream of the power switches, these then having to be closed during the entire operating phase in the latter case. Preferably the operating converter is connected to the battery upstream of the power switches to avoid this closure, requiring safety checks, when the high voltage network is not otherwise used.

[0014] Preferably in the invention, the rest converter is capable of providing a maximum power to the on-board network less than or equal to a maximum consumption power of the on-board network when the vehicle is in standby mode. This maximum power is determined for example by averaging the power consumed on the on-board network during the entire duration of a standby phase of the vehicle and adding a safety margin. It is significantly lower than the power required when the vehicle is in an operating phase (driving or life on board for example).Indeed, being used only in standby mode of the vehicle, the rest converter is for example sized to provide a few Watts, and at most between 10% and 30% of the nominal power of the on-board network, that is to say of the power consumed by the on-board network in nominal operation, measured for example by averaging the power consumed on the on-board network during the entire duration of an operating phase of the vehicle. This allows savings in terms of material resources (small size of the rest converter) and in energy consumption (better efficiency at low power of the rest converter).

[0015] In one embodiment of the invention, the first set of battery cells is identical to the second set of battery cells and comprises all of the battery cells. This embodiment of the invention makes it possible to dispense with a specific balancing device for the battery cells.

[0016] According to a preferred feature of the invention, the electrical power supply system according to the invention comprises two operating converters, each connected at the input to all of the cells of the battery. This feature makes it possible to ensure safe redundancy of the power supply to the on-board network during the operating phase, and in particular to guarantee the power supply of safety systems such as a braking system or a trajectory control system. The operating converters also operate independently, in particular they each comprise a separate control unit, which means that in the event of a failure of one of the operating converters, this failure does not cause a malfunction of the other operating converter.

[0017] The two operating converters are for example each connected upstream of the power switches, which makes it possible not to have to close the power switches to use them and therefore to supply the on-board network, thus avoiding a safety verification procedure of the high-voltage network when no high-voltage equipment of the vehicle needs to be supplied. In an alternative embodiment, one of the two operating converters is connected to the input downstream of the power switches and the other of the operating converters is connected to the input upstream of the power switches. This alternative makes it possible to use the converter connected to the battery downstream of the power switches, to precharge the input capacitors or inductances of equipment such as a charger or an inverter for controlling an electric machine, before connecting this equipment to the battery.This means that a specific pre-charging system can be dispensed with, especially if the power switches are power relays.

[0018] In an alternative embodiment of the invention, the electrical power supply system according to the invention comprises two operating converters, one connected at the input to the first set of cells of the battery and the other to a third set of cells of the battery, the first set and the third set forming a partition of at least part of the battery. In this alternative, the first set and the third set preferably each comprise half of the cells of the battery. A balancing device makes it possible to discharge each half of the cells in a quasi-identical manner, this balancing device being able to be software and consist of an activation of each of the converters for an identical duration, or so that they each supply the same quantity of energy to the consumers of the on-board network of the vehicle.Of course, other variant embodiments of the invention are conceivable, for example with more than two operating converters, each powered by all the cells of the battery or by a subset of cells of the battery, the subsets being able to form a partition of the cells of the battery. The first, second and third sets of cells of the battery can in particular be entirely superimposed or two by two, or form a partition of all the cells of the battery.

[0019] According to a preferred characteristic of the invention, each of the operating converters is capable of supplying a nominal power to the on-board network strictly lower than a maximum consumption power of the on-board network when the vehicle is in the operating phase. Thus, when the consumers of the on-board network consume little electrical energy, only one of the operating converters, consuming little operating energy (because they are optimized in their design for small loads of the on-board network, which is the most common case in the use of a vehicle), is used to supply the on-board network. For example The operating converters are each sized to provide half of the maximum consumption power of the on-board network, which is the electrical power supplying the on-board network required by the vehicle to operate in all conditions. This maximum power is measured, for example, during a driving phase when all the consumers of the on-board network are activated, and in particular the air conditioning, in extreme weather conditions. In another example, their respective nominal powers are between 50 and 90% of the maximum consumption power of the on-board network when the vehicle is in the operating phase. These are, for example, operating converters that can vary from 2kW to 4kW (kiloWatt) of nominal power. Limiting them to 2kW instead of 4kW also saves hardware resources while ensuring the safety redundancy mentioned above.

[0020] The electrical power supply system according to the invention further preferably comprises an electrical energy storage member connected to the on-board network upstream of a fuse box to which consumers of the on-board network are connected. This energy storage member is for example a supercapacitor integrated in the battery pack according to the invention. It makes it possible to reduce the amplitude of current draws on the on-board network, and to smooth the current during transient phases such as in particular a switch to standby mode, in the operating phase or a change of operating converter to supply the on-board network. Alternatively, this energy storage member is a small lead-free battery such as a small lithium battery.

[0021] The invention also relates to a battery pack for an electric or hybrid vehicle, comprising a housing housing an electrical power supply system according to the invention, the battery pack comprising two high-voltage connection terminals and one low-voltage connection terminal. In addition to the advantages linked to the electrical power supply system according to the invention, the battery pack has the advantage of securing it, by electrically isolating the high-voltage components of the electrical power supply system from the chassis of the vehicle, and by protecting them from impacts. The operating converters and their controls are in particular protected in the battery pack, from the vibration and thermal stresses of the engine compartment. Optionally, when the electrical power supply system according to the invention comprises an operating converter downstream of the power switches, this is arranged outside the battery pack.Finally, when the electrical power supply system according to the invention comprises two operating converters and one is dedicated to supplying the safety systems, the other being dedicated to supplying non-safety systems of the vehicle, the battery pack comprises two low voltage connections, i.e. a low voltage connection for supplying the safety systems. safety systems and the other for powering non-safety systems. It should be noted that the battery pack is also connected to the vehicle's ground, to connect one of the outputs of each operating or resting converter.

[0022] The invention also relates to a method for managing the power supply of the on-board network of a vehicle equipped with a vehicle supervision device, capable of managing the consumption of vehicle equipment during operating phases, the vehicle being equipped with an electrical power supply system according to the invention, and / or equipped with a battery pack according to the invention, the method comprising steps of: - waking up of the supervision device, the supervision device being powered by the rest converter, - activation of said at least one operating converter, - supply of electrical power to at least one consumer of the vehicle's on-board network.

[0023] Prior to the wake-up step, the vehicle is asleep and the supervision device is only powered to receive a request from, for example, vehicle equipment, an external server or a vehicle unlocking key. The subsequent activation of the operating converter corresponds to the waking up of its control unit, thus enabling the operation of the operating converter, and therefore the current conversion, as soon as the on-board network voltage measured by the control unit is lower than a voltage setpoint imposed by the control unit. The operating converter can thus supply the consumers of the on-board network, which includes the vehicle supervision device.

[0024] Optionally, when the request is linked to a need to activate high-voltage equipment of the vehicle, the supply step is followed by a step of detecting a request to activate the high-voltage equipment of the vehicle, and a step of closing the power switches following the detection step.

[0025] When the electrical power supply system according to the invention comprises two operating converters, preferably in the supply step, when each of the two operating converters is capable of supplying on its own the electrical power requested by said at least one consumer, then only one of the two operating converters operates simultaneously, a first of the two converters being regulated according to a first voltage setpoint, and a second of the two converters being regulated according to a second voltage setpoint, the first voltage setpoint alternating between a high voltage setpoint value and a low voltage setpoint value, the second voltage setpoint taking the low voltage setpoint value when the first voltage setpoint takes the high voltage setpoint value, and conversely taking the high voltage setpoint value. setpoint when the first voltage setpoint takes the low setpoint voltage value. The high setpoint voltage value is strictly greater than the low setpoint voltage value, these high and low voltage values ​​being included in the nominal voltage range of the on-board network. For example, the high voltage value is taken equal to a maximum value of the nominal voltage range of the on-board network while the low voltage value is taken equal to the minimum value of the nominal voltage range of the on-board network. This alternation makes it possible in particular to stress the operating converters in a similar way and therefore to extend their service life, and to easily detect a failure of one of the operating converters.

[0026] Furthermore, in the supply stage, when the electrical power requested by said at least one consumer is greater than the maximum power that can be supplied by one of the two operating converters, then the two operating converters operate simultaneously. This makes it possible to undersize each of the operating converters in relation to a maximum power consumption of the on-board network, as mentioned above.

[0027] According to a preferred characteristic of the method for managing the power supply of the on-board network according to the invention, the latter comprises a step of monitoring a battery voltage, the monitoring step triggering: - when the battery voltage falls below a first low threshold, a step of deactivating said at least one operating converter, and - when the battery voltage falls below a second low threshold strictly lower than the first low threshold, a step of deactivating the rest converter.

[0028] It should be noted that these thresholds are never reached during a nominal operating or resting phase of the vehicle, but only in the event of a very long rest period (several months) leading to a slow but progressive discharge of the battery. They are therefore defined to avoid any deep discharge of the battery.

[0029] These deactivations prevent the operation of the converters concerned, their control units being asleep but able to receive a message allowing them to be woken up.

[0030] This additional feature allows a minimum voltage level in the battery to be extended as much as possible, reducing its consumption in standby mode, which can allow the vehicle to be restarted without having to connect a restart device to the on-board network. This restart device is in fact necessary to wake up the vehicle's monitoring device and recharge the battery from a charging station, for example, when the battery is completely discharged.

[0031] The invention finally relates to a vehicle equipped with an electrical power supply system according to the invention, integrated for example in the battery pack according to the invention. The vehicle further comprises a monitoring device capable of managing the consumption of vehicle equipment during operating phases. The monitoring device and the electrical power supply system according to the invention comprise means for implementing the management method according to the invention.

[0032] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0033] [Fig.l] represents an electrical power supply system according to the invention, for equipment of an electric or hybrid vehicle, in one embodiment of the invention,

[0034] [Fig.2] represents a first variant embodiment of the electrical power supply system of [Fig.l],

[0035] [Fig.3] represents a second variant embodiment of the electrical power supply system of [Fig.l],

[0036] [Fig.4] represents the evolution over time of the regulation setpoint voltages of two operating converters and one idle converter of an electrical power supply system of [Fig.l], 2 or 3,

[0037] [Fig.5] represents the evolution as a function of time of a voltage of a battery of the electrical power system of [Fig.l], 2 or 3, the battery discharging while the vehicle comprising the electrical power system is in a period of prolonged standby, and

[0038] [Fig.6] represents steps of a method for managing the power supply of an on-board network of the vehicle comprising the electrical power supply system of [Fig.l], 2 or 3.

[0039] According to an embodiment of the invention shown [Fig.l], an electrical power supply system 1 of an electric or hybrid vehicle comprises a battery 8 of electrical accumulators connected in series, these accumulators being, for example, cells using Lithium-ion technology. Of course, other technologies can be used, for example that of Nickel metal hydride batteries. The battery 8 of the electrical power supply system 1 is a so-called traction battery, therefore “high voltage”, free of lead, the power of which allows an electric powertrain of the vehicle to operate. Its maximum no-load voltage is, for example, between 200V and 800V, in this embodiment.

[0040] Battery 8 is housed in a battery pack 3, which is a crash-resistant enclosure. Battery pack 3 has two high-voltage outputs 12 and 22 connected to a network high voltage of the vehicle. In particular, the electric powertrain is connected as an input to these outputs, which are on the one hand a positive high voltage connection terminal 12, connected to one of the ends of the battery 8 via a fuse 15 and a positive power switch 14, connected in series, and on the other hand a negative high voltage connection terminal 22, connected to the other of the ends of the battery 8 via a pyroswitch 17 and a negative power switch 16, connected in series. The fuse 15 and the pyroswitch 17 are connected upstream of the power switches 14 and 16 respectively. A precharging system is also connected in parallel with the power switch 14, this precharging system comprising in series a precharging resistor 1 and a precharging switch 18.The pre-charging system makes it possible to avoid the formation of an excessively high current draw when connecting the battery 8 to a battery charger or to a charging terminal comprising input inductances or capacitances. Alternatively, in particular when the positive 14 and negative 16 power switches are made by MOSFET transistors (for "metal-oxide-semiconductor field-effect transistor"), the electrical power supply system 1 does not include a pre-charging system and / or fuse devices 15, 17.

[0041] The power switches 14, 16, 18 as well as the precharging system and the fuse devices 15, 17 are elements of the electrical power supply system 1 which are integrated into the battery pack 3, which allows them to be electrically isolated in the engine compartment of the vehicle, and to protect them in the event of a crash.

[0042] In order to supply 14V to low voltage consumers of the vehicle, connected by electrical connections 92 to a fuse box 90, the electrical supply system 1 comprises, in the battery block 3:

[0043] - a first direct current converter - direct current 4 or first "operating converter", connected at the input in parallel to the battery 8 upstream of the power switches 14, 16, 18 and at the output to an on-board network 50 of the vehicle. More precisely, a first output of the first operating converter 4 is connected to a low voltage output 14V of the battery pack 3, this low voltage output 14V being connected to the on-board network 50, itself connected to the fuse box 90, and a second output of the first operating converter 4 is connected to a ground of the vehicle.

[0044] - and a second direct current converter - direct current 6 or second "operating converter", connected in parallel to the battery 8 upstream of the power switches 14, 16, 18 and in output to the on-board network 50 of the vehicle. A first output of the second operating converter 6 is connected to the low voltage output 14V of the battery pack 3, and a second output of the second converter operating terminal 6 is connected to the vehicle ground.

[0045] The first and second operating converters 4, 6 supply the on-board network 50 when the vehicle is "awake", i.e. in the operating phase. In this state, a supervision device 10 of the vehicle, for example a main computer, manages the consumption and activation of the various equipment of the vehicle, which may be low-voltage consumers such as a car radio or specific computers, as well as power devices such as an air conditioning compressor or an electric traction motor. In this embodiment of the invention, each of the first and second operating converters 4, 6 is sized to deliver 2kW in maximum operation, i.e. half of a total consumption on the on-board network 50, estimated at 4kW (these values ​​are a function of the vehicle equipment). In other words, the efficiency of each of the operating converters 4, 6 is optimal between 0 and 2kW.

[0046] The nominal power of each operating converter 4, 6 is thus substantially equal to half the power of a standard electric vehicle converter, and provides at most 2KW in nominal operation, i.e. for example 150 amps at 12.5V. This nominal power of a single operating converter 4, 6 is thus sufficient to power the safety systems of the vehicle and allow an emergency stop in the event of a breakdown, in particular it is greater than 1KW, and can provide at least 100A at 12.5V.

[0047] These choices allow for two operating converters that, in cost, volume and weight, save compared to two standard electric vehicle converters. Alternatively, each operating converter 4, 6 has a nominal power greater than 2kW but less than 3kW.

[0048] To supply at least the on-board network 50 when the vehicle is in standby mode, i.e. when stopped without using vehicle equipment for an extended period, the electrical power supply system 1 also comprises in the battery pack 3, a direct current - direct current converter 2 called a "rest converter", connected at the input in parallel to the battery 8 upstream of the power switches 14, 16, 18 and at the output to the on-board network 50 of the vehicle. A first output of the rest converter 2 is connected to the low voltage 14V output of the battery pack 3, and a second output of the rest converter 2 is connected to the ground of the vehicle.

[0049] The rest converter 2 allows the vehicle's computers, through the low voltage it supplies to the on-board network 50, for example 1 IV, to receive requests triggering their wake-up. Being intended for the vehicle's standby power supply, it is sized to supply a few tens of milliamps in nominal operation, i.e. for example between 0.5 and 5 Watts. In other words, the efficiency of the rest converter 2 is optimized for a few Watts. Its operation is provided by a control unit 20 powered directly at the output of the idle converter 2, therefore always activated. The control unit 20 is not subject to an external deactivation device, which contributes to the reliability of its power supply. The control unit 20 is for example a microcontroller.

[0050] The operating converters 4, 6 are activated during a transient wake-up phase of the vehicle, by the supervision device 10 which sends an activation message to corresponding control units 40, 60. The respective operation of each operating converter 4, 6 is in fact ensured by the respective control unit 40, 60 powered by the first output of the corresponding operating converter 4, 6, inside the battery pack 3 which secures these power supplies. The control units 40, 60 are for example microcontrollers.

[0051] The battery pack 3 integrates, in addition to the control units 20, 40, 60 of the rest converters 2 and operating converters 4, 6, a battery management module 32, monitoring, via sensors, the temperature and voltage of the battery cells. The management module 32 is in particular capable of opening the power switches 14, 16, 18 in the event of a fault in the battery 8. The management module 32 is hardware and software, and may in particular include temperature sensors and / or one or more pre-programmed electronic circuits.

[0052] The battery pack 3 comprises a CAN bus (from the English "Controller Area Network") output 70 to which the control units 20, 40, 60 and the management module 32 of the battery 8 are connected. The CAN bus output 70 is connected to a CAN bus of the vehicle, bus to which the supervision device 10 is connected, which is located outside the battery pack 3. Thus the supervision device 10 can in particular send CAN messages to the control units 40, 60 to activate them in the transient phase of waking up the vehicle, or to deactivate them in the transient phase of putting the vehicle to sleep. The CAN bus also allows the supervision device 10 to communicate with the management module 32 when a user connects the vehicle to a charging terminal.

[0053] When the control units 20, 40, 60 are activated, each is capable of operating its respective converter 20, 40, 60 so that it provides a low voltage current at its output when the voltage of the on-board network 50 is lower than a regulation setpoint voltage of the respective control unit 20, 40 or 60, as will be detailed later in relation to [Fig. 4]. The voltage of the on-board network 50 is measured independently by each control unit 20, 40, 60, for example the control unit 40 uses a voltage sensor 42 at the output of the first operating converter 4, and the control unit 60 uses a separate voltage sensor 62 at the output of the second operating converter 6.

[0054] The power supply system 1 also includes, integrated in the block battery 3, a supercapacitor 24, for example of the DLC type (from the English "Double Layer Capacitance"), connected in parallel to the outputs of the rest converters 2 and operating converters 4, 6. This supercapacitor 24 makes it possible to smooth the current draws on the on-board network 50 while always guaranteeing a stable voltage on the on-board network 50, for example in the range 10.5V to 15V. The supercapacitor 24 also makes it possible to secure certain transient phases, which are for example the waking up or sleeping of the vehicle, or the moment between the appearance of an electrical fault in one of the converters 2, 4, 6 and the melting of a fuse device internal to these components. The integration of this in the battery pack 3 makes it possible to secure the electrical power supply system 1, but also to simplify the electrical wiring of the electrical power supply system 1 and therefore its cost.

[0055] Furthermore, when there is a short circuit at the fuse box, the fuse corresponding to the faulty consumer causing this short circuit melts thanks to the electric current of several hundred amperes supplied over a short interval (less than one second) by at least one of the operating converters 4, 6 and / or the supercapacitor 24. As a variant, a pyroswitch is arranged on one of the electrical connections 92, preferably serving several consumers, which avoids oversizing the supercapacitor 24 or the operating converters 4, 6. In yet another variant, a current sensor detects such a short circuit and acts on a switch, for example a transistor, to cut the electrical connection 92 concerned.

[0056] The rest converters 2 and operating converters 4, 6 being connected upstream of the power switches 14, 16, 18, the electrical supply system 1 of [Fig.l] makes it unnecessary to close the power switches 14, 16 in order to be able to supply the on-board network 50 via the rest converters 2 or operating converters 4, 6.

[0057] [Fig. 2] shows a power supply system 11 according to the invention, which is a first variant embodiment of the embodiment of [Fig. 1]. The power supply system 11 comprises elements common to the power supply system 1 which are referenced in the same way and not re-detailed. The components of the power supply system 11 are integrated in a battery pack 30 similar to the battery pack 3. The battery pack 30 differs only from the battery pack 3 in that it does not comprise a pre-charging system, and in that the second operating converter 6 is connected to the battery 8 downstream of the power switches 14, 16, while the first operating converter 4 is connected upstream of the power switches 14, 16. Thus in this first variant embodiment:

[0058] - when the vehicle is in standby mode, the on-board network 50 is powered by the rest converter 2 only,

[0059] - when the vehicle is awake but the power switches are open, the on-board network 50 is powered by the first operating converter 4 only, and

[0060] - when the vehicle is awake but the power switches are closed, the on-board network 50 is powered by the first operating converter 4 and / or the second operating converter 6.

[0061] In this first embodiment, the second operating converter 6 is reversible, that is to say capable of electrically supplying the high voltage network of the vehicle from the on-board network 50, which means that a pre-charging system is not required. Indeed, for example, when a charger comprising an input capacitor is connected to the high voltage network, it must be pre-charged before closing the power switches 14, 16 if it is desired to avoid an electric arc that could stick these power switches, when these are electrical relays.

[0062] Thanks to this first embodiment variant, the second operating converter 6 uses the energy from the on-board network 50, supplied by the first operating converter 4, to precharge this capacity before the relays 14, 16 close.

[0063] In this first embodiment, the second operating converter 6 and its control unit 60 are preferably integrated into the battery pack 30 to secure them, but they may possibly be arranged outside the battery pack 30, for example for reasons of space requirement in the battery pack 30.

[0064] [Fig. 3] shows a power supply system 111 according to the invention, which is a second alternative embodiment of the embodiment of [Fig. 1]. In this second alternative, the elements common to the power supply system 1 are referenced in the same way and not re-detailed. The components of the power supply system 111 are integrated into a battery pack 300 similar to the battery pack 3. The battery pack 300 differs only from the battery pack 3 in that the battery is a storage battery 80 partitioned into two blocks 81 and 82 of electric storage batteries, between which a connection terminal called a midpoint makes it possible to split the power supply of the two operating converters 4, 6 into two independent power supplies.Thus the first operating converter 4 is powered by the block 81 by being connected at the input to the midpoint and to the end of the battery 80 connected to the positive high voltage connection terminal 12 via the fuse 15 and the positive power switch 14. The second operating converter 6 is powered by the block 82 by being connected at the input to the midpoint and to the end of the battery 80 connected to the negative high voltage connection terminal 22 via the pyroswitch 17 and the negative power switch 16.

[0065] The electrical power supply system 111 thus makes it possible to secure the power supply to the on-board network 50 by a redundancy of energy sources. Thus, in the event of failure of one of the accumulator blocks 81, 82, the on-board network 50 is powered by the other of the blocks 81, 82, which allows the safety systems of the vehicle to be functional while a driver of the vehicle parks it on the shoulder. The first and second operating converters 4, 6 are identical in this second embodiment, to allow balancing of the battery 80. In addition, the first and second operating converters 4, 6 each supply the same quantity of energy to the on-board network 50 to allow this balancing, for example by means of alternating operation now presented in relation to [Fig. 4].

[0066] [Fig. 4] shows an example of regulation setpoint voltages of the rest converters 2 and operating converters 4, 6 of the electrical power supply systems 1, 11 or 111 when the vehicle is in an operating phase and therefore awake. During this operating phase, the rest converter 2 having a setpoint voltage Vt2 of 11.5V is activated, in the sense that its control unit 20 is able to operate it as soon as the voltage of the on-board network 50 drops below 11.5V. However, during this operating phase, the rest converter 2 does not operate, the voltage of the on-board network 50 being maintained at 14V by one of the rest converters 4, 6 throughout this operating phase, in this example of use of the invention.

[0067] It is further assumed that during this operating phase, the on-board network 50 consumes little, and that only one of the operating converters 4, 6, the output current of which is limited to a maximum current value of 150A (amperes) to avoid overheating of the operating converter 4, 6, is capable of supplying the energy required by the consumers of the on-board network 50. As a result, only one of the converters 4, 6 operates alternately, for example for a duration of one hour h each, to supply the on-board network 50.Thus during the first hour of the operating phase, the first operating converter 4 is regulated by its control unit 40 to a setpoint voltage Vt4 of 14V, taken equal to a high setpoint voltage value allowing the nominal operation of the consumers of the on-board network 50, while the second operating converter 6 is regulated by its control unit 60 to a second setpoint voltage Vt6 of 12V, taken equal to a low setpoint voltage value strictly lower than the high setpoint voltage value. The following hour, the first operating converter 4 is regulated by its control unit 40 to the low setpoint voltage value while the second operating converter 6 is regulated by its control unit 60 to the high setpoint voltage value. The high setpoint voltage value and the value. low setpoint voltage differ by at least one volt to avoid untimely operation of the two operating converters 4, 6 simultaneously.

[0068] During this operating phase, the supercapacitor 24 filters the voltage oscillations on the on-board network 50, in particular between two setpoint voltage transitions of the converters 4, 6.

[0069] Of course, other ways of alternating the use of the operating converters 4, 6 are conceivable, for example one of the operating converters 4, 6 operates alone over a complete operating phase of the vehicle, then the other of the operating converters 4, 6 operates alone over the next operating phase of the vehicle. When the durations of the operating phases of the vehicle differ significantly, one of the operating converters 4, 6 is for example used alone over two successive operating phases to compensate for these differences.

[0070] Furthermore, when the electrical power required on the on-board network 50 is greater than the maximum power that can be supplied by one of the two operating converters 4, 6, then the two operating converters 4, 6 operate simultaneously, each being regulated to the high set voltage value.

[0071] After a phase of vehicle operation, the supervision device 10 triggers the vehicle to go to sleep, and therefore to switch it to standby mode, for example following the locking of the vehicle doors. It then deactivates the two operating converters 4, 6, in the sense that it commands the control units 40, 60 of these converters 4, 6 to no longer control their operation by supervising a voltage of the on-board network 50, but to manage only the reception of CAN messages. It also puts most of the computers, the management module 32 and itself into standby mode. Once in standby mode, the on-board network 50 is therefore only powered by the rest converter 2. Its efficiency is optimized to avoid any waste of energy when the vehicle is asleep.

[0072] After a certain time, if the vehicle is asleep for too long or not recharged, the state of charge of the battery 8, 80 becomes low when the vehicle goes to sleep, and it may happen that the battery 8, 80 discharges completely. To avoid damaging the battery 8, 80, the control unit 20 of the rest converter 2 then implements steps of a method 100 for managing the power supply of the on-board network 50 according to the invention, presented in FIGS. 5 and 6.

[0073] The management method 100 comprises a step of monitoring the voltage Vb of the battery 8, 80, this step being implemented continuously by the management module 32 in the operating phase, or by the control unit 20 in standby mode.

[0074] The first period Tl of time in [Fig.5] corresponds to an operating phase 140 of the vehicle, during which the rest converters 2 and the converters operating converters 4, 6 are awakened or active. When the voltage Vb of the battery 8, 80 falls below a first low voltage threshold Vbl, for example 180V (for a battery with a nominal voltage of 400V), the supervision device 10 triggers 190 the vehicle to go to sleep, during which it deactivates 200 the operating converters 4, 6, and we move on to a second time period T2.

[0075] The second period T2 corresponds to a phase during which the vehicle is asleep, and during which the operating converters 4, 6 are inactive, only the rest converter 2 supplying the on-board network 50. The battery 8, 80 therefore discharges less quickly during the second period T2 than during the first period T1. During the second period T2, the control units 40, 60 have a minimum operating voltage, for example less than 20% of their nominal operating voltage, a value imposed by the rest converter 2.

[0076] The third time period T3 corresponds to a phase during which the vehicle is asleep, and where the battery voltage 8.80 has fallen below a second low voltage threshold Vb2, for example 140V.

[0077] When the battery voltage falls below this second low voltage threshold Vb2, the rest converter 2 self-deactivates 220, the supply voltage of its control unit 20 dropping to zero voltage after the storage device 24 has been completely discharged. For this, the rest converter 2 comprises a battery voltage sensor 8, 80, or receives a message from the management module 32, when the latter integrates a reverse wake-up function triggered by a too low voltage of the battery 8, 80. The discharging of the battery 8, 80 by electrical loads is stopped during the third period T3. The rest converter 2 being deactivated, it no longer operates, the on-board network 50 no longer being supplied.

[0078] When the battery 8, 80 is completely discharged, two electrical terminals on the on-board network 50 allow an external 14V charger to be connected 230, in order to wake up the supervision device 10 and allow the battery 8, 80 to be recharged by connecting the vehicle to an external charging terminal, and / or sufficient recharging of the battery 8, 80 using one of the operating converters 4, 6 to allow the starting of a thermal engine of the vehicle when the latter is a hybrid vehicle. The 14V charger is left connected until the voltage Vb of the battery 8, 80 allows at least the power supply of the on-board network 50 via the rest converter 2, that is to say the power supply of its control unit 20 at its nominal voltage level.

[0079] [Fig.6] further presents other steps of the method 100 for managing the power supply of the on-board network 50 of the vehicle, implemented according to the steps concerned, by the supervision device 10 of the vehicle, the control units 20, 40, 60 of the converters of the electrical power supply system 1, 11 or 111, the converters of the power supply system 1, H or 111 themselves, the battery 8, 80, the management module 32 of the battery 8, 80, or several of these elements in cooperation with each other.

[0080] A state 110 prior to the implementation of a first step 120 of waking up the vehicle, corresponds to a standby mode of the vehicle, during which the on-board network 50 is powered by the rest converter only, the supervision device 10 of the vehicle being asleep.

[0081] The vehicle wake-up step 120 is triggered by the reception, by the supervision device 10, of a request from a piece of vehicle equipment, an external server or a vehicle unlocking key.

[0082] The next step 130 is then the activation by the supervision device 10 of the operating converters 4, 6, corresponding to the sending of a CAN wake-up message to their respective control units 40, 60. These therefore wake up and one of them controls the operation of at least one of the operating converters 4, 6. During this transient phase of waking up the operating converters 4, 6, the supercapacitor 24 supplies the current necessary to the on-board network 50 to power the components already woken up, such as for example the vehicle's computers, while one of the operating converters 4, 6 supplies 14V to the on-board network 50. The supervision device 10 also activates, after its waking step 120, other equipment of the vehicle.

[0083] The next step 140 is the power supply of the on-board network 50 by one or other of the operating converters 4, 6, or by both operating converters 4, 6 simultaneously, depending on the power required by the consumers connected to the on-board network 50. An alternation of regulation setpoint voltages is implemented when only one of the operating converters 4, 6 is able to provide this required power, as described previously in relation to [Fig. 4]. This alternation is for example implemented by the supervision device 10, the control units 40, 60 and the operating converters 4, 6. In addition, the rest converter 2 does not operate during this step, being regulated at 11.5V, except possibly in the event of failure of one of the operating converters 4, 6 and high consumption on the on-board network 50.

[0084] The step 140 of supplying the on-board network 50 comprises a step 150 of detection by the supervision device 10 of a request for activation of high-voltage equipment of the vehicle. In the case where such an activation request is received by the supervision device 10 (branch Y in [Fig. 6]), the following step 160 is the closing of the power switches 14, 16 by the supervision device 10. The closing of the positive power switch 14 is preceded by a closing and then an opening of the precharge switch 18 when the system power supply 1, 111 comprises such a precharge switch.

[0085] The next step 170 is then the power supply of the high voltage network of the vehicle by the battery 8, 80. When the high voltage network is no longer requested by a piece of equipment of the vehicle, we move on to the next step 180 of opening the power switches 14, 16, implemented by the supervision device 10, and the management method 100 loops back to the step 150 of detecting a request to activate a piece of high voltage equipment of the vehicle.

[0086] When, on the contrary, in the step 140 of supplying the on-board network 50, the supervision device 10 does not detect a request for activation of high-voltage equipment of the vehicle (branch N), the management method 100 moves to a step 190 of detecting conditions for falling asleep of the vehicle. These conditions are, for example, the locking of the vehicle while it is stationary, without requesting consumers of the on-board network 50 other than the vehicle's computers.

[0087] When the conditions for putting the vehicle to sleep are not met (branch N of step 190), the management method 100 loops back to step 150 of detecting a request to activate high-voltage equipment of the vehicle.

[0088] When, on the contrary, the conditions for putting the vehicle to sleep are met or when the voltage Vb of the battery 8, 80 falls below the first low voltage threshold Vbl (branch Y of step 190), the supervision device 10 triggers the putting the vehicle to sleep, and the next step is the deactivation 200 of the operating converters 4, 6 as described previously in relation to [Fig. 5]. Then, the control unit 20 of the rest converter supervises 210 the battery voltage Vb. If the battery voltage Vb falls below the second low voltage threshold Vb2 (branch Y of step 210) before the vehicle wakes up during a new step 120 of waking up the vehicle, the rest converter 2 deactivates 220 as also mentioned in relation to [Fig. 5], and the next waking up 120 of the vehicle will require the use 230 of an external 14V charger.

[0089] On the contrary, if the battery voltage Vb has remained above the second low voltage threshold Vb2 during a next wake-up 120 of the vehicle (branch Y of step 210), this next wake-up 120 is carried out without an additional step after step 210 of supervision of the battery voltage Vb by the control unit 20 of the rest converter 2.

[0090] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the characteristics of the different variant embodiments of the invention envisaged in this application can be combined to achieve the invention, insofar as these variants are not incompatible with each other.

Claims

Claims

1. Electrical power supply system (1, 11, 111) for equipment of an electric or hybrid vehicle, comprising: - a battery (8, 80), capable of supplying the energy necessary for the operation of an electric powertrain of the vehicle, - power switches (14, 16, 18) capable of connecting the battery (8, 80) to the electric powertrain of the vehicle, - at least one direct current - direct current converter (4, 6), called operating converter, capable of supplying an on-board network (50) of the vehicle during operating phases of the vehicle, the operating converter (4, 6) being connected at the input to a first set (8, 81, 82) of cells of the battery (8, 80) and at the output to the on-board network (50) of the vehicle, - a direct current - direct current converter (2), called a rest converter, connected on the one hand at the input to a second set (8, 80) of cells of the battery (8, 80) upstream of the power switches (14, 16, 18) and on the other hand at the output to the on-board network (50) of the vehicle, the rest converter being intended to supply the vehicle when it is in standby mode, - a control unit (40, 60) of the operating converter (4, 6), powered by the on-board network (50) of the vehicle, and - a control unit (20) of the rest converter (2), powered by the on-board network (50) of the vehicle.

2. Electrical power supply system (1, 11, 111) according to claim 1, wherein the rest converter (2) is capable of supplying a maximum power to the on-board network (50) less than or equal to a maximum consumption power of the on-board network (50) when the vehicle is in standby mode.

3. Electrical power supply system (1, 11, 111) according to claim 1 or 2, further comprising an electrical energy storage member connected to the on-board network upstream of a fuse box to which consumers of the on-board network are connected.

4. A power supply system (1, 11, 111) according to any one of claims 1 to 3, wherein the first set of battery cells is identical to the second set of battery cells and comprises all of the battery cells (8, 80).

5. Power supply system (1, 11, 111) of claim 4, comprising two operating converters (4, 6), each connected as input to all the battery cells (8, 80).

6. A power supply system (11) according to claim 5, wherein one (6) of the two operating converters (4, 6) is connected as an input downstream of the power switches (14, 16, 18) and the other (4) of the operating converters (4, 6) is connected as an input upstream of the power switches (14, 16, 18).

7. Power supply system (1, 11, 111) according to any one of claims 1 to 3, comprising two operating converters (4, 6), one connected at the input (6) to the first set (82) of cells of the battery (8, 80) and the other (4) to a third set (81) of cells of the battery (8, 80), the first set (82) and the third set (81) forming a partition of at least a part of the battery (8, 80).

8. Electrical power supply system (1, 11, 111) according to any one of claims 5 to 7, in which each of the operating converters (4, 6) is capable of supplying a nominal power to the on-board network (50) strictly lower than a maximum consumption power of the on-board network (50) when the vehicle is in the operating phase.

9. Battery pack (3, 30, 300) for an electric or hybrid vehicle, comprising a housing housing an electrical power supply system (1, 11, 111) according to any one of claims 1 to 8, the battery pack (3, 30, 300) comprising two high voltage connection terminals (12, 22) and a low voltage connection terminal.

10. Method for managing (100) the power supply of the on-board network (50) of a vehicle equipped with a vehicle supervision device (10), capable of managing the consumption of vehicle equipment in operating phases, the vehicle being equipped with an electrical power supply system (1, 11, 111) according to any one of claims 1 to 8, and / or equipped with a battery pack (3, 30, 300) according to claim 9, comprising steps of: -waking up (120) of the supervision device (10), the supervision device (10) being powered by the rest converter (2), - activation (130) of said at least one operating converter (4, 6), - supply (140) of electrical power to at least one consumer of the on-board network (50) of the vehicle.

11. Method for managing (100) the power supply of the on-board network (50) according to claim 10 taken in dependence on any one of claims 5 to 8, wherein in the supply step (140), when each of the two operating converters (4, 6) is capable of supplying on its own the electrical power requested by said at least one consumer, then only one of the two operating converters (4, 6) operates simultaneously, a first of the two converters (4) being regulated according to a first voltage setpoint (Vt4), and a second of the two converters (6) being regulated according to a second voltage setpoint (Vt6), the first voltage setpoint (Vt4) alternating between a high voltage setpoint value and a low voltage setpoint value, the second voltage setpoint (Vt6) taking the low voltage setpoint value when the first voltage setpoint (Vt4) takes the high voltage setpoint value,and conversely taking the high value of the set voltage when the first voltage set point (Vt4) takes the low value of the set voltage.,

12. Method for managing (100) the power supply of the on-board network (50) according to claim 10 or 11 taken in the dependency of claim 8, in which in the supply step (140), when the electrical power requested by said at least one consumer is greater than the maximum power that can be supplied by one of the two operating converters (4, 6), then the two operating converters (4, 6) operate simultaneously.

13. Method for managing (100) the power supply of the on-board network (50) according to any one of claims 10 to 12, comprising a step of monitoring a battery voltage (Vb), the monitoring step triggering: - when the battery voltage (Vb) becomes lower than a first low threshold (Vbl), a step of deactivating (200) said at least one operating converter (4, 6), and - when the battery voltage (Vb) becomes lower than a second low threshold (Vb2) strictly lower than the first low threshold (Vbl), a deactivation step (220) of the rest converter (2).

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