ELECTRICAL POWER TRANSFER SYSTEM FOR AN ELECTRIFIED VEHICLE

Abstract

The present invention relates to an electrical power transfer system (1) for a vehicle comprising a power battery (2), a charging interface (3), a battery charger (5), an electrical load (7) operating at alternating voltage, a means (8) for measuring the current consumed by the load (7), a power junction device (9) between the charger (5), the charging interface (3) and the load (7), said junction device (9) being controllable and adapted to operate at least a first connection configuration in which power is transferred from the charging interface (3) simultaneously to the load (7) and the charger (5), and a controller (6) configured to control a maximum charging current setpoint for the battery (2) as a function of a remaining current calculated based on the current consumed by the load. Figure 1.

Description

Title of the invention: ELECTRICAL POWER TRANSFER SYSTEM FOR AN ELECTRIFIED VEHICLE

[0001] The field of the invention relates to an electrical system for a vehicle allowing the simultaneous charging of a battery and an on-board consumer operating in alternating voltage.

[0002] Plug-in electric vehicles include a power interface designed for connecting a charging station. The traction battery of a vehicle is recharged using an on-board charger that includes a voltage converter to transform alternating current into direct current.

[0003] Vehicle manufacturers are seeking to develop an on-board electrical system capable of powering an on-board load operating at alternating voltage from the battery. Electrical architectures are known that include a bidirectional on-board charger that recharges the battery from the external terminal and powers an on-board load from the energy stored in the traction battery. However, the load cannot be powered during a battery charging operation because the bidirectional converter is already being used for AC / DC conversion. One way to solve this problem is to add a dedicated DC / AC converter to power the on-board load from the energy stored in the battery. However, this solution increases the cost of the electrical system.

[0004] It is also necessary to ensure that the current demands of the on-board charger and the consumer do not exceed the current limits of the charging station, otherwise its electrical protections may be triggered.

[0005] Patent document CN115267307A describing an electrical measuring device protected against overcurrents and temperature rises is known. Patent document US-A1-2020086743 describing a vehicle electrical system comprising an on-board generator supplying a power outlet for connecting an alternating current device is also known. A controller implements an electrical protection solution configured to control the current delivered by the generator according to the temperature of the power outlet. This electrical system is limited in power by the capacity of the vehicle's on-board generator and may be insufficient to power high-power equipment for extended periods, such as a refrigeration system. It also does not allow the battery to be recharged simultaneously with the operation of the power outlet.

[0006] There is therefore a need to address the aforementioned problems. One objective of the invention is to provide an electrical system for an electrified vehicle that allows a battery to be charged at a charging station simultaneously with the power supply to a load operating at alternating voltage. Another objective is to provide a monitoring system that prevents the risk of triggering the electrical protection devices of the charging station.

[0007] More specifically, the invention relates to an electrical power transfer system for a vehicle comprising:

[0008] - a power battery,

[0009] - a charging interface for connecting an external power source designed to operate on alternating voltage.

[0010] - a battery charger comprising a bidirectional power converter,

[0011] - an electrical consumer operating on alternating voltage,

[0012] - a means of measuring the current consumed by the consumer.

[0013] According to the invention, the system further comprises:

[0014] - a power junction device between the charger, the charging interface and the consumer, said junction device being controllable and adapted to operate at least one initial connection configuration in which power is transferred from the charging interface simultaneously to the consumer and the charger,

[0015] - a configured controller, when the first connection configuration is performed, For :

[0016] - determine a maximum charging current deliverable by the energy source external,

[0017] - measure the current consumed by the consumer,

[0018] - calculate a remaining current for the battery charging requirements as a function of the Maximum current and current consumption

[0019] - and in which the charger is configured to drive a current setpoint of maximum battery charge depending on the remaining current when the battery is charged.

[0020] According to one variant of the system, the controller is configured, when the first connection configuration is operated, to determine if the current consumed by the electrical consumer is greater than the maximum current deliverable by the external energy source, and, if a need for additional current is detected, to control the bidirectional power converter so that the battery delivers the additional current required by the consumer.

[0021] According to one variant of the system, the controller is configured to limit the current consumed by the consumer if it is detected that the current consumed reaches a maximum current that can be delivered simultaneously by the external power source and by the battery.

[0022] According to one variant of the system, the junction device is adapted to operate a second connection configuration in which the charger is controlled to transfer power from the charging interface to the battery and in which the junction device is controlled to disconnect the consumer in the event of detection of a lack of use of the consumer.

[0023] According to one variant of the system, said junction device is adapted to transfer power from the charging interface to the consumer and in which the bidirectional power converter is controlled so that the battery injects power towards the external power source.

[0024] According to one variant of the system, said junction device is adapted to operate a third connection configuration in which the charging interface is not connected to an external power source and in which the bidirectional power converter is controlled so that the battery transfers power to the consumer.

[0025] An electrified motor vehicle is also envisaged, comprising a traction chain that is at least partially electrified and including an electrical system according to any of the preceding embodiments.

[0026] The invention further provides a method for controlling an electrical power transfer system as defined by any one of the preceding embodiments, comprising the following steps when the first connection configuration is established:

[0027] - the determination of a maximum charge current deliverable by the source external energy,

[0028] - the measurement of the current consumed by the consumer,

[0029] - the calculation of a remaining current for the battery charging requirements as a function of the maximum current and the current consumed,

[0030] - controlling the maximum battery charging current setpoint as a function of the remaining current when the battery is being charged.

[0031] According to one variant, the method further comprises:

[0032] - the verification consisting of determining if the current consumed by the consumer is greater than the maximum current deliverable by the external power source,

[0033] - and, if a need for additional current is detected, the control of the bidirectional power converter so that the battery delivers the additional current needed by the consumer.

[0034] According to one variant, the method further includes limiting the current consumed by the consumer in the event of detection that the current consumed reaches a maximum current that can be delivered simultaneously by the external energy source and by the battery.

[0035] According to the invention, a controller is provided comprising means specifically configured to implement the control method according to any one of the preceding embodiments.

[0036] According to the invention, a computer program is provided comprising instructions which, when the program is executed by a controller of the electrical system, lead the latter to implement any one of the embodiments of the control method.

[0037] It is further provided a computer-readable recording medium comprising instructions which, when executed by a computer, lead the latter to implement the control method according to the invention.

[0038] The electrical system allows power to be delivered to an on-board vehicle load operating at alternating voltage simultaneously with an alternating voltage battery charging operation. The invention avoids the need for a dedicated DC / AC converter to power the load from the battery. This solution reduces the cost of the power function.

[0039] Other features and advantages of the present invention will become more apparent upon reading the following detailed description, which includes embodiments of the invention given by way of non-limiting examples and illustrated by the accompanying drawings, in which:

[0040] [Fig-1] represents the electrical power transfer system according to the invention.

[0041] [Fig.2] represents a first electrical system connection configuration according to the invention.

[0042] [Fig.3] represents a second electrical system connection configuration according to the invention.

[0043] [Fig.4] represents a third electrical system connection configuration according to the invention.

[0044] [Fig.5] represents the power transfer control method according to the invention.

[0045] The invention applies to electrified vehicles, that is to say, comprising a traction chain at least partially electrified, preferably motor vehicles, but not only such as aircraft, trucks, tractors, bicycles, ships.

[0046] In [Fig. 1], the electrical system 1 for an electrified vehicle according to the invention is schematically represented by a block diagram. The electrical system 1 comprises a power battery 2, a charging interface 3 for connecting an external power source 4 operating at alternating voltage, a battery charger 5 including a bidirectional power converter 51, a electrical consumer 7 operating in alternating voltage, a means of measuring 8 the current consumed by the consumer 7, a power junction device 9 between the charger 5, the charging interface 3 and the consumer 7.

[0047] More specifically, the battery 2 is an energy storage system designed for the needs of the electric traction system (not shown in [Fig. 1]) comprising a plurality of electrochemical energy storage elements. The battery delivers an electrical voltage adapted for the associated electric traction machine and which can range from several tens to several hundreds of volts, for example, 48 volts, 400 volts, or 800 volts. An electrochemical energy storage element, also called an electrochemical cell, is a storage element having two electrical connection terminals and a voltage of a few volts, most often between approximately 2.3V and 4.2V.The cells can be of the Lithium-ion type (lithiumized Nickel Manganese Cobalt oxide (NMC) or lithium iron phosphate (LFP) are examples of active materials for the positive electrode), Nickel Cadmium (Ni-Cd), Nickel Metal Hydride (Ni-MH), Sodium-ion, Lead-acid, or even fuel cell type, for example. More precisely, a lithium-ion cell is mainly composed of a porous positive electrode, a porous negative electrode, a separator, and an electrolyte (which can be liquid, polymeric, or solid). The operating principle of a Lithium-ion cell is based on the reversible exchange of Lithium ions between the two porous electrodes.

[0048] The charger 5 includes power electronics comprising at least one bidirectional power converter 51 enabling the conversion of alternating voltage to direct voltage for charging the battery and the conversion of the battery's direct voltage to alternating voltage, in particular for powering the electric machine, for powering the consumer 7, or for transferring power to the charging interface in order to inject power into a power distribution network or a domestic electrical network. The charger 5 further includes a controller 52 designed for communication between the charger 5 and one or more vehicle controllers and adapted in particular for communication with an external power source via the charging interface 3.The controller 52 is adapted to manage communication information between the power source 4 and the charger 5, including the maximum charging current setpoint commanded by the charger 5, and the maximum charging current deliverable by the power source 4. Typically, the charger 5 is adapted for power loads up to 350 kW.

[0049] More specifically, the junction device 9 includes power lines and controlled power relays for opening and closing the power lines and to establish several power connection configurations between the charger 5, the charging interface 3 and the consumer 7.

[0050] The junction device 9 is controllable to operate at least one first connection configuration, illustrated in [Fig.2], where the charger 5, the consumer 7 and the charging interface 3 are electrically connected by power lines and in which power (represented by the dashed arrows) is transferred from the charging interface 3 simultaneously to the consumer 7 and the charger 5.

[0051] This first configuration allows them to be powered simultaneously when the converter 51 of the charger 5 is driven in charging mode and avoids integrating a specific converter dedicated to transferring power from the battery to the consumer 7. The invention further provides a current control function to guarantee the electrical needs of the consumer 7 when it is powered during charging and to prevent the electrical protections of the external source from tripping by controlling the current demanded by the vehicle in relation to the capacities of the external source 4. This control function will be described in more detail later in the description.

[0052] In this first configuration, the converter 51 of the charger 5 can be operated in a discharge mode to inject power from the battery 2 to the charging interface 3, in order to inject power into the distribution network (V2G for "Vehicle To Grid"), to a home network (V2H for "Vehicle To Home"), to an external load via an adapter (V2L for "Vehicle To Load"), or to a building's power supply network (V2B for "Vehicle To Building"). These operating modes are generically designated by the acronym V2X for "Vehicle To Everything". Simultaneously, the discharge mode can supply power to the load 7 if needed.

[0053] Furthermore, the device 9 can be controlled in a second connection configuration illustrated in [Fig.3] where only the charger 5 is electrically connected by the power lines to the charging interface 3 and in which the charger 5 is controlled to transfer power (represented by the dashed arrows) from the charging interface 3 to the battery 2 and to disconnect the consumer 7. This second configuration is controlled to charge the battery 2 in the event of detection of no use of the consumer 7.

[0054] This second connection configuration can also be controlled to control the charger 5 in discharge mode so as to transfer power from the battery 2 to the charging interface 3.

[0055] Furthermore, the device 9 can be operated in a third connection configuration illustrated in [Fig. 4] where the charger 5 is electrically connected only to consumer 7 by the power lines and in which the charger 5 is controlled in discharge mode to transfer power (represented by the dashed arrows) from battery 2 to consumer 7.

[0056] Furthermore, the charging interface 3 is typically a charging socket housing adapted for connecting the vehicle to an external power source 4 via a charging cable, or it may be a deployable cable from the vehicle that can be directly connected to an external power source 4. The interface 3 is adapted to operate in Mode 1, Mode 2, Mode 3, or Mode 4 charging modes, allowing power transfer of up to 350 kW. The interface 3 may include a connector conforming to SAE J1772 or IEC 62196. The power source 4 may be a home charging station, a public charging station, or a standard household outlet. The power source 4 operates on single-phase or three-phase alternating current, or on direct current.

[0057] Furthermore, the on-board consumer 7 operates on alternating voltage and is intended to be electrically powered by the charger 5 and / or the external power source 4. The consumer 7 can be a refrigeration unit for example or a power panel allowing the connection of one or more power units.

[0058] Furthermore, the electrical system 1 includes a means for measuring 8 the current consumed by the consumer 7. The measuring means is a current sensor 8 adapted to deliver instantaneous current information to a controller 6.

[0059] More specifically, the controller 6 is intended to collect at every instant the information of current consumed from the sensor 8 and the information of maximum current deliverable by the external energy source 4 when it delivers power to the charging interface 3. The controller 6 can be a dedicated computer for the implementation of the invention, integrated into the controller 52 of the charger 5 or integrated into a vehicle supervision computer.

[0060] To ensure the proper operation of the load 7 when powered by the external power source, the controller 6 is configured to calculate at any given moment the remaining current required to charge the battery 2, based on the maximum current delivered by the power source 4 and the current consumed by the load 7. Thus, the electrical system 1 is configured to determine at any given moment the maximum charging current setpoint for the battery 2 by subtracting the current consumed from the maximum deliverable current. This value is calculated or communicated to the controller 52 of the charger 5, which then adjusts the charging speed of the battery 2 according to the instantaneous current of the load 7. In the event of a high demand on the load 7, the electrical system 1 prevents an excessive demand situation that could trigger the electrical protection of the external source or cause overheating of the power connections.

[0061] Furthermore, the controller 6 is adapted to determine if the current consumed by the electrical load exceeds the maximum current deliverable by the external power source, and, if the need is detected, it is configured to control the bidirectional power converter so that battery 2 delivers the additional current required by the load 7. This mode ensures the proper operation of the load 7. In addition, the controller 6 is configured to limit the current consumed by the load if it detects that the current consumed reaches a maximum current deliverable simultaneously by the external power source 4 and by battery 2. The current limitation can be a reduction or a complete shutdown of the load.

[0062] Furthermore, the electrical system 1 includes a power link and an electric traction machine (not shown in [Fig. 1]) which can be directly connected to the power converter 51 or to the junction device 9. More generally, the term electric traction machine refers to any electric machine, whether direct current or alternating current, preferably with a polyphase stator, of the permanent magnet synchronous or asynchronous type. An electric machine can be used to generate torque for a traction system or to produce electrical power.

[0063] In [Fig. 5], a method for controlling the electrical power transfer system as defined by [Fig. 1] is schematically represented by a logic diagram. The method is implemented by a control unit of the electrical system, for example the controller 6.

[0064] The control unit is equipped with an integrated circuit computer and electronic memory, the computer and memory being configured to execute the control process. However, this is not mandatory. Indeed, the computer could be external to the control unit, while still being coupled to it. In this latter case, it could itself be arranged as a dedicated computer including, for example, a dedicated program. Consequently, the control unit, according to the invention, can be implemented in the form of software modules, electronic circuits, or hardware, or a combination of electronic circuits and software modules.

[0065] The control method includes a first initialization step SL. The electrical system and the computers are started. The sequence occurs when an external power source is connected to the charging interface and, when it is available to deliver a charging current, a power relay of the electrical connection is closed to connect the source to the junction device. The junction device is then controlled in the first configuration where the charger, the load, and the external power source are electrically connected. Furthermore, the The consumer is designed to start operating as soon as power can be supplied.

[0066] Another scenario is envisaged in which the load is already operating and is powered by the electrical system's battery. Once the external source is available to deliver current, the charging interface and the load are electrically connected. The charger can then be commanded to terminate the DC / AC voltage conversion and subsequently operate in AC / DC charging mode to charge the battery. According to another operating mode, the charger can supply supplementary current from the battery to the onboard load if needed.

[0067] Next, the method includes, at each instant, a second step S2 of determining a maximum charging current Imax deliverable by the external energy source. The control unit of the electrical system is adapted to collect this information via the charger's computer.

[0068] The process further comprises a third step S3 of Measurement of current consumed by the on-board consumer of the electrical system.

[0069] The method further comprises a fourth calculation step S4 of a remaining current Irest for the battery charging requirements as a function of the maximum current Imax and the current consumed Icons. The remaining current Irest has a value equal to the maximum current Imax minus the value of the current Icons. This value ensures the electrical needs of the consumer are met.

[0070] To this end, the method further includes a fifth step S5 for controlling the maximum charging current setpoint delivered by the charger to the external power source based on the remaining current Irest. When the battery is being charged, the charger transmits the Irest value, thereby ensuring that the load's needs are met and that the charging station's current limits are respected. This prevents the electrical protection devices from tripping. During this phase, the load is powered by the external source, and simultaneously, the charger and the battery operate in charging mode by transferring energy from the external source to the battery.

[0071] A variant of the process is also envisaged comprising a sixth verification step S6 consisting of determining whether the current Icons consumed by the electrical consumer is greater than the maximum current Imax deliverable by the external energy source.

[0072] If a need is detected, the process includes a seventh step S7 of controlling the bidirectional power converter in discharge mode so that the battery delivers the additional current required by the load. During this phase, the load is powered simultaneously by the external source and the battery. An eighth step, S8, can also be implemented to limit the current consumed by the load if it is detected that the current consumption reaches a maximum current that can be delivered simultaneously by the external power source and the battery. The load operates in a degraded mode to prevent the electrical protection devices from tripping. Current limitation can take the form of a reduction or complete shutdown of the load. The generation of an alert signal can also be included.

[0073] If no need is detected, the process remains at step S5 where the charger operates in battery charging mode.

[0074] The invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different variant embodiments of the invention by combining, for example, the different features above taken alone or in combination, without departing from the scope of the invention.

Claims

Demands

1. An electrical power transfer system (1) for a vehicle comprising: - a power battery (2), - a charging interface (3) for connecting an external power source (4) designed to operate at alternating voltage, - a battery charger (5) including a bidirectional power converter (51), - an electrical load (7) operating at alternating voltage, - a means (8) for measuring the current consumed by the load (7), the system being characterized: - in that it further comprises a power junction device (9) between the charger (5), the charging interface (3) and the load (7), said junction device (9) being controllable and adapted to operate at least one first connection configuration in which power is transferred from the charging interface (3) simultaneously to the load (7) and the charger (5), - in that it further comprises a configured controller (6),when the first connection configuration is performed, to: - determine (S2) a maximum charging current deliverable by the external power source, - measure (S3) the current consumed by the load, - calculate (S4) a remaining current for the charging needs of the battery (2) as a function of the maximum current and the current consumed, - and in that the charger (5) is configured to control a maximum charging current setpoint for the battery (2) as a function of the remaining current when the battery is being charged.

2. System (1) according to claim 1 wherein the controller (6) is configured, when the first connection configuration is operated, to: - determine (S6) whether the current consumed by the electrical consumer (7) is greater than the maximum current deliverable by the external power source (4), - and, if a need for additional current is detected, to control (S7) the bidirectional power converter (51) so that the battery (2) delivers the additional current required by the consumer (7).

3. System (1) according to claim 2 in which the controller (6) is configured to limit the current consumed by the consumer (7) in the event of detection that the current consumed reaches a maximum current deliverable simultaneously by the external power source (4) and by the battery (2).

4. System (1) according to any one of claims 1 to 3 wherein said junction device (9) is adapted to operate a second connection configuration wherein the charger (5) is controlled to transfer power from the charging interface (3) to the battery (2) and wherein the junction device (9) is controlled to disconnect the consumer (7) in the event of detection of a lack of use of the consumer (7).

5. System according to any one of claims 1 to 4 wherein said junction device (9) is adapted to transfer power from the load interface (3) to the consumer (7) and wherein the bidirectional power converter (51) is controlled so that the battery (2) injects power towards the external power source (4).

6. System according to any one of claims 1 to 5 wherein said junction device (9) is adapted to operate a third connection configuration in which the charging interface (3) is not connected to an external power source (4) and in which the bidirectional power converter (51) is controlled so that the battery (2) transfers power to the consumer (7).

7. Electrified motor vehicle comprising a drivetrain at least partially electrified and comprising an electrical system (1) according to any one of claims 1 to 6.

8. A method for controlling an electrical power transfer system as defined by any one of claims 1 to 6, the method being characterized in that it comprises the following steps when the first connection configuration is operated: - the determination (S2) of a maximum load current deliverable by the external energy source (4), - the measurement (S3) of the current consumed by the consumer (7), - the calculation (S4) of a remaining current for the charging needs of the battery (2) as a function of the maximum current and the current consumed, - the control (S5) of the maximum charging current setpoint of the battery (2) as a function of the remaining current when the battery is being charged.

9. A control method according to claim 8 further comprising: - the verification (S6) consisting of determining whether the current consumed by the consumer (7) is greater than the maximum current deliverable by the external power source (4), - and, if a need for additional current is detected, the control (S7) of the bidirectional power converter (51) so that the battery (2) delivers the additional current required by the consumer (7).

10. A control method according to claim 9 further comprising limiting the current consumed by the consumer (7) in the event of detection that the current consumed reaches a maximum current deliverable simultaneously by the external power source (4) and by the battery (2).

Images