Charging system for electric or hybrid vehicles and associated vehicles

Abstract

The present invention relates to a charging system (1) for an electric or hybrid vehicle comprising a traction battery (2), an inverter (3) and an AC motor (4), comprising a voltage booster assembly (5), first connection means (11, 12) for connecting the traction battery (2) to the input of the inverter (3), and second connection means (13, 14) for connecting a charging socket (8) to the input of the voltage booster assembly (5), characterized in that the charging system (1) further comprises third connection means (14, 15) by which the traction battery (2) can be directly connected to the charging socket (8).

Description

Summary of the Invention

[0001] The present invention relates to the fields of automotive and electrical technology, and more particularly to charging systems for electric or hybrid vehicles and vehicles equipped with such charging systems.

[0002] Electric or hybrid vehicles have a high-voltage traction battery that discharges to power the electric traction motors that provide traction force to the vehicle. Therefore, the vehicle requires a system for charging the traction battery. Such a system recharges the traction battery by recovering energy while the vehicle is braking or from a charging station external to the vehicle. Currently, charging stations do not always provide the same type of charging. Therefore, a vehicle charging system should preferably include multiple types of chargers depending on the type of charging, such as a charger dedicated to AC charging and a device dedicated to DC charging via an external charger.

[0003] Therefore, in order to meet all of these requirements, such a charging system may prove to be very bulky and very expensive, especially if certain components of the charging system are not made as multipurpose as possible. It is particularly known practice to use the stator field coils of the electric vehicle's traction electric motor, and the associated traction inverter, to create a vehicle charger voltage booster stage, as described, for example, in document FR 2943188.

[0004] Similarly, to reduce the cost and complexity of the charging system, it is preferable to use only one charging socket for connecting to a DC charging station, regardless of the level of voltage that this charging station can supply. However, certain vehicles are now equipped with traction batteries that have maximum no-load voltages that are significantly greater than the maximum available voltage levels output by conventional charging stations, which means that in such vehicles, the charging socket used for DC charging can no longer be connected directly to the vehicle's traction battery, but must instead be connected to the input of a voltage boost stage whose output is connected to the traction battery.

[0005] If this voltage boost stage uses the stator field coil of the vehicle's electric motor and the vehicle's inverter, this means that this motor and this inverter must be specified to be able to withstand the traction battery charging current regardless of the level of voltage supplied by the charging station. In other words, even if an electric motor and inverter capable of withstanding a maximum phase current of, for example, 130 A (amperes) is sufficient for normal vehicle operation, the vehicle must incorporate an electric motor and inverter capable of withstanding a much higher maximum phase current corresponding to the traction battery charging current supplied by a charging station that also delivers a very high charging voltage, for example, of the order of 800 V (volts).

[0006] Additionally, systematically passing the traction battery charging current through the voltage boost stage results in electrical losses in the components of the voltage boost stage, even when that voltage boost function is not being used.

[0007] Finally, the design of such charging systems is guided by the desire to minimize the number of controlled switches to reduce the cost, bulk and complexity of the system, and also the desire to minimize the number of times these switches are activated to avoid premature wear.

[0008] The present invention seeks to at least partially overcome the shortcomings of the prior art with a charging system for an electric or hybrid vehicle and such vehicle that is capable of charging the vehicle's traction battery using a DC charging station, regardless of whether the voltage level provided by the charging station is lower or higher than that of the traction battery, without having to overspecify the vehicle's electric motor and inverter, and while minimizing electrical losses during charging.

[0009] To this end, the invention provides a charging system for an electric or hybrid vehicle, the vehicle comprising a traction battery and an inverter connectable at its input to the traction battery and at its output to an AC motor, the charging system comprising a voltage booster assembly, the charging system additionally comprising first connection means for connecting the traction battery to the input of the inverter and second connection means for connecting a charging socket to the input of the voltage booster assembly, A charging system is proposed, characterized in that the charging system further comprises third connection means by which the traction battery can be directly connected to the charging socket.

[0010] By "directly connected" is meant that a third connection means is capable of connecting the charging socket to the terminals of the traction battery without passing through the voltage booster assembly, and when the third connection means is used, there are few zero-resistance or near-zero-resistance conductors or components separating the charging socket from the traction battery.

[0011] Additionally, in this patent application, unless otherwise stated, a connection with an input or output of a functional assembly such as an inverter or voltage booster assembly is understood to be a connection with the terminals of this input or output, respectively, i.e. a parallel connection with this input or output, respectively, where the output of the inverter (with respect to its inverter function) is in particular connected to the phase connections of the electric motor of the vehicle.

[0012] Also in this patent application, a traction battery is understood to be a battery that powers the inverter and electric motor when the vehicle is driven, as opposed to a vehicle's auxiliary battery that powers the vehicle's low-voltage electrical network (e.g., 14 V) to which various consumers, including the vehicle's main computer, are connected. Thus, a traction battery may also be understood to be a propulsion battery, depending on the electric motor used. Unless otherwise stated, the battery referred to in this patent application is the vehicle's traction battery. Similarly, in this patent application, the terms "motor" and "inverter" refer to the vehicle's electric traction or propulsion motor and traction or propulsion inverter, unless otherwise indicated. Finally, the terms "charge" and "recharge" are considered equivalent in this patent application.

[0013] According to the present invention, the DC current for charging the traction battery passes through the voltage booster assembly when the first and second connection means are used, or reaches the traction battery directly when the first and third connection means are used. In the latter case, this corresponds to charging while the vehicle is connected to a charging station that provides a charging voltage higher than the voltage at the terminals of the traction battery. Because this current does not pass through the voltage booster assembly, the charging current delivered by such a charging station does not suffer electrical losses within the voltage booster assembly. This additionally avoids the need to overspecify the vehicle's electric motor and inverter to allow such charging (with a charging voltage higher than the battery voltage) compared to the specifications they require for normal vehicle operation.

[0014] Preferentially, the charging system comprises an inverter, a motor and control means for controlling the inverter and the motor to form a voltage booster assembly, thus reducing the space required in the engine compartment and the cost of producing this voltage booster assembly using dedicated components.

[0015] In one embodiment of the present invention, in the charging system according to the present invention, the first connecting means comprises at least a first switch, called the battery positive switch, connected by its first terminal to the positive terminal of the traction battery and by its second terminal to the positive input terminal of the inverter, and a second switch, called the battery negative switch, connected by its first terminal to the negative terminal of the traction battery and by its second terminal to the negative input terminal of the inverter; the second connecting means comprise, on the one hand, a first switch, called a DC positive switch, connected by its first terminal to the positive terminal of the charging socket and by its second terminal to the positive input terminal of the voltage booster assembly, and, on the other hand, a second switch, called a DC negative switch, connected by its first terminal to the negative terminal of the charging socket and by its second terminal to the negative input terminal of the voltage booster assembly; The third connecting means comprises a DC negative switch and a switch called a bypass switch, which is connected by its first terminal to the first or second terminal of the DC positive switch and by its second terminal to the second terminal of the battery positive switch. Preferentially, the positive input terminal of the voltage booster assembly is connected to the first terminal of a switch called a booster switch, which is itself connected by its second terminal to the inductor of the voltage booster assembly. This ensures safe operation while the booster switch is open so that no current can pass through the voltage booster assembly. In the case where the voltage booster assembly is formed by an inverter and a motor, the second terminal of the booster switch is connected to the neutral point of the AC motor. Additionally, in this case, the negative terminal of the voltage booster assembly corresponds to the negative terminal of the inverter (in the sense that they are at the same potential).

[0016] The connections described herein above with respect to the terminals of the switches shall be understood to mean direct connections, i.e. connections made by components of zero or almost zero resistance having only a conductive function, except insofar as these may serve as fuses for additional switches which do not form part of the subject matter of the present invention.

[0017] This approach minimizes the number of switches in the charging system by using DC negative switches both when charging the traction battery with the voltage booster assembly and when charging the battery without the assembly. These switches are power switches, such as mechanical relays or MOSFETs (metal-oxide-semiconductor field-effect transistors). The first and second terminals of each switch correspond to terminals of the switch that are distinct from each other.

[0018] In a preferred variant of this embodiment of the invention, the bypass switch is connected by its first terminal to the first terminal of the DC positive switch. This preferred variant embodiment of the invention means that the DC positive relay does not need to be closed when the traction battery is being charged without using the voltage booster assembly. In addition, if said assembly comprises an input capacitor, this variant avoids the need to couple this capacitor to a smoothing capacitor connected to the input of the traction battery, which could have a negative impact on the charging or charging system.

[0019] In another variation of this embodiment of the invention, the bypass switch is connected by its first terminal to the second terminal of the DC positive switch. In this case, the DC positive switch is closed when the traction battery is being charged without the voltage booster assembly. This can be advantageous when changing directly from charging the traction battery with the voltage booster assembly to charging the traction battery without the voltage booster assembly because only one switch needs to change state in this transition.

[0020] In this embodiment of the invention, the charging system according to the invention comprises, on the one hand, communication means for communicating with a DC charging station to which the charging socket is connected, which means are capable of determining the charging voltage delivered by the charging station, and, on the other hand, control means for controlling the first, second and third connection means, which are capable of closing the battery positive and negative switches and the DC positive and negative switches when the charging voltage determined by the communication means is lower than the voltage of the traction battery, and of closing the DC negative switch and the bypass switch when the charging voltage determined by the communication means is higher than the maximum no-load voltage of the traction battery. Naturally, when the charging voltage determined by the communication means is lower than the traction battery voltage, the bypass is opened or remains open. Likewise, in a preferred variant of this embodiment of the invention, the DC positive switch is opened or remains open when the charging voltage determined by the communication means is higher than the traction battery voltage. On the other hand, in another variant, the DC positive switch is kept closed or is closed when the charging voltage determined by the communication means is higher than the traction battery voltage. Finally, the control means may close the battery positive and negative switches and the DC positive and negative switches when the charging voltage determined by the communication means is higher than the traction battery voltage but lower than the maximum no-load voltage of the traction battery.

[0021] Preferentially, the voltage booster assembly further comprises a capacitor, called a booster capacitor, connected by its first terminal to the negative input terminal of the voltage booster assembly and by its second terminal to the first terminal of the booster switch, which in particular makes the start of charging using the voltage booster assembly safer.

[0022] The present invention also relates to an electric or hybrid vehicle comprising a charging system according to the present invention and a traction battery, further comprising a connection unit comprising a connector electrically connected to the input of the inverter, a connector electrically connected to the charging socket, a connector electrically connected to the traction battery, and a connector electrically connected to the positive input terminal of the voltage booster assembly, the connection unit comprising battery positive and negative switches, DC positive and negative switches, and a bypass switch, which makes wiring and assembly easier.

[0023] The connection unit also includes a pre-charging device having a first terminal connected to the positive terminal of the battery and a second terminal connected to the positive input terminal of the inverter.

[0024] The term "electrically connected" means a direct connection without intermediate switches. The connection unit therefore makes it possible to group together the main switches of the charging system (except for the voltage booster switches), especially if these are mechanical relays, and to establish electrical safety around these main switches. The connection unit also makes maintenance of these main switches easier.

[0025] In one embodiment of the invention, the electric or hybrid vehicle according to the invention further comprises a smoothing capacitor connected to the output of the voltage booster assembly, which is therefore connected to the input of the inverter and serves to smooth the current delivered to the traction battery when the inverter is operating as a rectifier when recovering braking energy or when the voltage booster assembly is operating as a voltage booster.

[0026] According to an advantageous feature of the electric or hybrid vehicle according to the invention, the vehicle comprises detection means for detecting a stuck bypass switch after charging of the traction battery using the bypass switch. This detection makes it possible to prevent the traction battery from being charged using a charging station having an available voltage level lower than that of the traction battery until such time as the switch is changed. "Stuck" here means that, in the case of a mechanical relay, the switch becomes stuck to its terminals, or, in the case of a MOSFET, the switch is damaged to the point that it cannot be turned off.

[0027] Advantageously, the electric or hybrid vehicle according to the invention comprises control means for controlling the traction battery voltage and the traction battery current, which control means are able to open the battery positive and negative switches and / or the DC positive and negative switches and / or the bypass switch if the control means detects an abnormality, for example an excessively rapid rise in the voltage of the battery or some of the battery cells.

[0028] Other characteristics and advantages of the invention will become more apparent from the following description on the one hand and from a number of non-limiting exemplary embodiments given by way of illustration with reference to the accompanying schematic drawings, in which: [Brief explanation of the drawings]

[0029] [Figure 1] 1 illustrates a charging system for charging a traction battery of an electric or hybrid vehicle in accordance with the present invention in one embodiment of the present invention. [Figure 2] 2 is a diagram showing the switch positions of the charging system of FIG. 1 under normal vehicle driving conditions. [Figure 3] FIG. 10 illustrates the positions of these switches during charging of the traction battery using a charging station that can provide a voltage that is at most less than the maximum no-load voltage of the traction battery. [Figure 4]FIG. 10 illustrates the positions of these switches during charging of the traction battery using a charging station that can provide a charging voltage that is at most higher than the maximum no-load voltage of the traction battery. DETAILED DESCRIPTION OF THE INVENTION

[0030] According to one embodiment of the invention shown in Figure 1, an electric or hybrid vehicle according to the invention comprises a charging system 1 according to the invention for recharging the vehicle's traction battery 2. The vehicle comprises a traction inverter 3 and a three-phase electric motor 4 connected to the vehicle's wheels by a drive train, the inverter 3 and the motor 4 being powered by the traction battery 2 for the purpose of putting the vehicle into operation.

[0031] For this purpose, the vehicle is provided with a first switch 11, called the battery positive switch, which has its first terminal connected to the positive terminal of the traction battery 2 and its second terminal connected to the positive input terminal of the inverter 3, for connecting the traction battery 2 to the inverter 3, and a second switch 12, called the battery negative switch, which has its first terminal connected to the negative terminal of the traction battery 2 and its second terminal connected to the negative input terminal of the inverter 3. The inverter input referred to here is the part of the inverter that receives DC current and transmits rectified current; i.e., the term "input" is to be understood in relation to the inverter function. Similarly, in this patent application, the terms "input" and "output" are to be understood in relation to the function of the referenced electrical assembly or component. A smoothing capacitor 7 is connected to the inverter input. This capacitor makes it possible to smooth the current entering the battery 2 when the inverter 3 is used as a rectifier for the current output by the electric motor 4 operating in generator mode.

[0032] The battery positive switch 11 and negative switch 12 therefore form a first means of connection between the traction battery 2 and the input of the inverter 3. Furthermore, the output of the inverter 3 is connected directly to the electric motor 4, i.e. without an intermediate switch.

[0033] The vehicle also comprises a DC-DC converter 30, which is connected to the terminals of the smoothing capacitor 7 and allows the recharging of an auxiliary battery 31 intended to power the vehicle's consumers (such as the lighting system). The vehicle also comprises a charger 32 with which the traction battery 2 can be recharged using an AC charging station. The charger 32 is connected at its output to the terminals of the smoothing capacitor 7 and at its input to a charging socket 33 dedicated to AC recharging. This charging socket 33 is, for example, a Type 2 connector complying with standard IEC 62196 (a set of standards of the International Electrotechnical Commission).

[0034] The vehicle further comprises a charging socket 8 intended to be connected to a DC charging station. This charging socket 8 is, for example, a CHAdeMO connector compliant with standard IEC 61851-23, -24. In one variant, the vehicle comprises only one charging socket that allows connection to both DC and AC charging stations, for example a ComboDC charging socket compliant with standard IEC 62196-3. In yet another variant, the vehicle has only one charging socket intended to be connected only to DC charging stations.

[0035] The charging system 1 comprises control means 40 for commanding the inverter 3 and the motor 4 to use the inverter 3 and motor 4 assembly 5 as a voltage booster stage when the traction battery 2 is being charged using a charging voltage delivered by the charging station that is lower than the maximum no-load voltage of the traction battery 2. In this case, the stator field coils of the electric motor 4 are therefore used as current storage inductors in the voltage boost assembly 5, and these stator field coils discharge through the inverter 3 into the traction battery 2 during a duty cycle of switching of the inverter 3 set by the control means 40, which comprises a voltmeter U measuring the voltage on the terminals of the booster capacitor 6.

[0036] The negative terminal of the booster capacitor 6 is connected to the negative input terminal of the inverter, and the positive terminal of the booster capacitor 6 is connected to the neutral point of the electric motor 4 via a switch 16. A first terminal of the switch 16, called a booster switch, is connected to the positive terminal of the booster capacitor 6 and to the neutral point of the electric motor 4 with its second terminal. This booster switch 16 makes it possible to disconnect the booster capacitor 6 at the input of the voltage booster assembly 5 outside the phase of charging of the traction battery 2 by an external charging station, and this booster switch 16 is in particular kept open when the vehicle is driven. Thus, capacitive coupling between the booster capacitor 6 and the electric motor 4 is avoided when the vehicle is driven.

[0037] The means 40 of control of the inverter 3 are for example a microcontroller which controls the switches of the inverter 3 in both the traction mode and the charging mode of the vehicle, the charging mode then using the booster function of the assembly 5 .

[0038] Second connection means of the vehicle allow the DC charging socket 8 to be connected to the input of the voltage booster assembly 5. To that end, these second means include: a switch 13, called DC positive switch, connected by its first terminal to the positive terminal of the charging socket 8 and by its second terminal to the booster switch 16; a switch 14 called DC negative switch, which is connected by a first terminal to the negative terminal of the charging socket 8 and by a second terminal to the negative input terminal of the inverter 3.

[0039] These second connection means are used to recharge the traction battery 2 via the voltage booster assembly 5 if the charging voltage of the charging station to which the charging socket 8 is connected is lower than the maximum no-load voltage of the battery 2.

[0040] Finally, the vehicle's third connection means allow the DC charging socket 8 to be connected directly to the traction battery 2 and are used to recharge this battery when the charging voltage of the charging station to which the charging socket 8 is connected is higher than the voltage on the terminals of the battery 2. The third connection means comprise a DC negative switch 14 and a switch 15, called a bypass switch, which is initially connected by its first terminal to the first terminal of the DC positive switch 13 and by its second terminal to the second terminal of the battery positive switch 11. As a variant, the bypass switch 15 is connected by its first terminal to the second terminal of the DC positive switch 13 and by its second terminal to the second terminal of the battery positive switch 11.

[0041] In this case, the switches 11, 12, 13, 14, and 15 are mechanical relays grouped together in the connection unit 9 of the charging system 1. The connection unit also includes a pre-charging relay 10, which is connected by one of its terminals to the positive terminal of the traction battery 2 and by its other terminal to the positive terminal of the inverter 3. A pre-charging resistor is connected between the pre-charging relay 10 and the positive terminal of the battery 2. Before charging the battery 2, the pre-charging relay 10 is first closed to charge the smoothing capacitor 7, then the pre-charging relay 10 is opened and the battery positive relay 11 is closed. The pre-charging relay 10 and the pre-charging resistor form a pre-charging device. It is noted that instead of such a relay and resistor system, other types of pre-charging devices may be used.

[0042] Electrical output from the connection unit 9 is via electrical connectors 17, 18, 19 and 21. Connector 18 is electrically connected to the input of the inverter 3, connector 17 is electrically connected to the charging socket 8, connector 21 is electrically connected to the traction battery 2, and connector 19 is electrically connected to the positive terminal of the booster capacitor 6.

[0043] Charging system 1 in this embodiment of the invention comprises a voltage booster assembly 5, a charger 32, charging sockets 8 and 33, and a connection unit 9. The charging system also comprises one or more software and / or hardware modules of a vehicle's main computer 50. In particular, main computer 50 comprises means for communicating with charging stations 60 or 70 (see Figures 3 and 4) which form part of charging system 1.

[0044] The charging system 1 also comprises control means for controlling the second and third connection means on the one hand and the booster switch 16 on the other hand, these control means being present in the main computer 50 of the vehicle.

[0045] The charging system 1 also comprises control means for controlling the pre-charging relay 10 and the battery positive and negative switches 11, 12, which control means are also present in a management system 20 that manages the traction battery 2 and which possibly forms an integral part of the charging system 1. The management system 20 for managing the battery 2 is coupled to a sensor 22 that senses the current entering the battery 2 (this sensor 22 is connected to an ammeter A in FIG. 1 ) and the charging voltage provided by the charging stations 60, 70 (this sensor 22 is connected to a voltmeter V in FIG. 1 ), enabling the management system to supervise the charging of the battery 2. The management system 20 for managing the battery 2 also comprises control means for controlling the bypass switch 15 and the DC positive and negative switches 13, 14. Thus, when the system 20 for managing the battery 2 detects a malfunction during charging, the management system can safely interrupt charging without intervention by the vehicle's main computer 50. Thus, the switches 10, 11, 12, 13, 14, 15 are each controllable by the management system 20 and by the vehicle's main computer 50, thus achieving safety-related redundancy. Similarly, the booster switch 16 is controllable by the main computer 50 and the control means 40.

[0046] To further enhance the safety of charging system 1, main computer 50 detects the possibility of sticking of one of switches 10, 11, 12, 13, 14, 15 or 16 used during charging of the traction battery at the end of this charging and imposes a downgraded operating mode on the vehicle if such a sticking is detected. This detection uses, for example, voltage measurements taken at various points within charging system 1.

[0047] The operation of the charging system 1 will now be described in relation to various scenarios of vehicle use, where the maximum no-load voltage of the traction battery is 800 V. Naturally, the invention can be used with batteries having a different value of maximum no-load voltage.

[0048] When the vehicle is being driven, as shown in FIG. 2 , the DC positive and negative switches 13 and 14, the bypass switch 15, the pre-charge relay 10, and the booster switch 16 are kept open by the charging system 1, while the battery positive and negative switches 11 and 12 are kept closed. Thus, the traction battery 2 supplies power to the inverter 3 and the electric motor 4, which provide the vehicle's propulsion or traction power. It should be noted that in this situation, the bypass switch 15 can be kept closed, for example, to limit the number of times it is activated or as a result of a switch failure, without impairing the operation of the vehicle during normal running. In contrast, in an embodiment variant in which the bypass switch 15 is connected by one of its terminals directly to the positive terminal of the booster capacitor 6 (i.e., without the DC positive switch being located between these two components), closing this switch would couple the booster capacitor 6 to the electric motor 4, which would be detrimental.

[0049] FIG. 3 illustrates a situation in which traction battery 2 is being charged using a charging station 60 that does not deliver a voltage level higher than the battery's maximum no-load voltage. For example, the charging station may deliver a charging voltage of at most 400 V or 500 V. In this example of the use of the present invention, it is assumed that the voltage at the terminals of battery 2 is higher than the maximum charging voltage delivered by charging station 60. By communicating with charging station 60 prior to charging battery 2, computer 50 is able to determine this maximum charging voltage and the fact that it is lower than the battery's maximum no-load voltage. During this charging, charging system 1 keeps booster switch 16, DC positive and negative switches 13 and 14, and battery positive and negative switches 11 and 12 closed. In contrast, charging system 1 keeps bypass switch 15 open. It should be noted that during this charging, the pre-charge relay 10 managed by the management system 20 is also kept open (except during the pre-charge period preceding this charging of the traction battery 2, when the pre-charge relay 10 is closed and the battery positive relay 11 is open).

[0050] In this situation, the charging voltage applied by the charging station 60 is applied to the booster capacitor 6 and the control means 40 controlling the inverter commands this voltage booster assembly 5 so that the voltage supplied at the output of the voltage booster assembly 5 (and therefore at the input of the inverter) is higher than the voltage of the battery 2.

[0051] 4 shows a situation in which the traction battery 2 is being charged using a charging station 70 that delivers a voltage level that can be as high as 820 V. The main computer 50, in communication with the charging station 70, has requested a higher charging voltage than the battery voltage 2, which itself is less than 800 V (if it needs to be recharged). During this charging of the traction battery 2 by the charging station 70, the charging system 1 keeps the booster switch 16 and the DC positive switch 13 open. During this charging, the pre-charge relay 10 is kept open (except during a pre-charge period preceding this charging of the traction battery 2, during which the pre-charge relay 10 is closed and the battery positive switch 11 is open). In contrast, the charging system keeps the DC negative switch 14, the bypass relay 15, and the battery positive and negative switches 11, 12 closed.

[0052] In this situation, the charging voltage delivered by the charging station 70 is applied directly to the terminals of the traction battery 2, without electrical losses produced by the inverter 3 or the electric motor 4, and without any undesirable capacitive effects. In contrast, it should be noted that in an embodiment variant in which the bypass switch 15 is connected by one of its terminals directly to the positive terminal of the booster capacitor 6, there would be a coupling between the booster capacitor 6 and the smoothing capacitor 7, which would be detrimental to the recharging of the battery 2. In addition, in this variant, the DC positive switch 13 is kept closed during this charging.

[0053] Naturally, the invention is not limited to the examples that have been described and many modifications may be made to these examples without departing from the scope of the invention.

Claims

1. A charging system (1) for an electric or hybrid vehicle, the vehicle comprising a traction battery (2) and an inverter (3) connectable at its input to the traction battery (2) and connectable at its output to an AC motor (4), the charging system (1) comprising a voltage booster assembly (5), the charging system (1) additionally comprising first connection means (11, 12) for connecting the traction battery (2) to the input of the inverter (3) and second connection means (13, 14) for connecting a charging socket (8) to the input of the voltage booster assembly (5), Charging system (1), characterized in that the charging system (1) further comprises third connection means (14, 15) by means of which the traction battery (2) can be directly connected to the charging socket (8).

2. 2. The charging system (1) of claim 1, comprising the inverter (3), the motor (4), and control means (40) for controlling the inverter (3) and the motor (4) to form the voltage booster assembly (5).

3. the first connection means (11, 12) comprise at least a first switch (11), called a battery positive switch, connected by its first terminal to the positive terminal of the traction battery (2) and by its second terminal to the positive input terminal of the inverter (3), and a second switch (12), called a battery negative switch, connected by its first terminal to the negative terminal of the traction battery (2) and by its second terminal to the negative input terminal of the inverter (3); The second connection means (13, 14) comprise, on the one hand, a first switch (13) called a DC positive switch, which is connected by its first terminal to the positive terminal of the charging socket (8) and by its second terminal to the positive input terminal of the voltage booster assembly (5), and, on the other hand, a second switch (14) called a DC negative switch, which is connected by its first terminal to the negative terminal of the charging socket (8) and by its second terminal to the negative input terminal of the voltage booster assembly (5); 3. The charging system (1) according to claim 1 or 2, wherein the third connecting means (14, 15) comprises the DC negative switch (14) and a switch (15) called a bypass switch, the switch (15) being connected by its first terminal to the first or second terminal of the DC positive switch (13) and by its second terminal to the second terminal of the battery positive switch (11).

4. 4. A charging system (1) according to claim 3, wherein the positive input terminal of the voltage booster assembly (5) is connected to a first terminal of a switch (16), called a booster switch, which is itself connected by its second terminal to an inductor of the voltage booster assembly (5).

5. 5. The charging system (1) according to claim 3 or 4, wherein the bypass switch (15) is connected by its first terminal to the first terminal of the DC positive switch (13).

6. 6. The charging system (1) according to claim 3, wherein the charging system (1) comprises, on the one hand, communication means (50) for communicating with a DC charging station (60, 70) to which the charging socket (8) is connected, the communication means (50) being capable of determining a charging voltage delivered by the charging station (60, 70), and, on the other hand, control means for controlling the first, second and third connection means, the control means being capable of closing the battery positive switch (11), the battery negative switch (12), and the DC positive switch (13), the DC negative switch (14) when the charging voltage determined by the communication means (50) is lower than the voltage of the traction battery (2), and of closing the DC negative switch (14) and the bypass switch (15) when the charging voltage determined by the communication means (50) is higher than the maximum no-load voltage of the traction battery (2).

7. 7. The charging system (1) according to any one of claims 4 to 6, characterized in that the voltage booster assembly (5) further comprises a capacitor (6), called a booster capacitor, connected by a first terminal thereof to the negative input terminal of the voltage booster assembly (5) and by a second terminal thereof to the first terminal of the booster switch (16).

8. 8. An electric or hybrid vehicle comprising the charging system (1) of any one of claims 3 to 7 and a traction battery (2), further comprising a connection unit (9), the connection unit (9) comprising a connector (18) electrically connected to an input of an inverter (3), a connector (17) electrically connected to the charging socket (8), a connector (21) electrically connected to the traction battery (2), and a connector (19) electrically connected to the positive input terminal of the voltage booster assembly (5), the connection unit (9) comprising the battery positive switch (11) and battery negative switch (12), the DC positive switch (13) and DC negative switch (14), and the bypass switch (15). An electric or hybrid vehicle.

9. 9. An electric or hybrid vehicle according to claim 8, comprising detection means (50) for detecting sticking of the bypass switch (15) after charging of the traction battery (2) using the bypass switch (15).

10. 10. An electric or hybrid vehicle according to claim 8 or 9, comprising control means (20, 50) for controlling the voltage of the traction battery (2) and the current of the traction battery (2), wherein, if the control means (20, 50, 40) detects an abnormality, the control means (20, 50) is capable of opening the battery positive switch (11) and the battery negative switch (12) and / or the DC positive switch (13) and the DC negative switch (14) and / or the bypass switch (15).

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