Electrical power supply circuit of a vehicle electrical energy storage unit

Abstract

Electrical circuit (4, 6) comprising: two input terminals (13) suitable for connection to a DC voltage, a control unit (7p, 7s), a first switching arm (B1, B3) comprising two electronically controllable switches (12) in series on either side of a first midpoint, the switches of this first arm being controlled according to a first duty cycle by the control unit, a second switching arm (B2, B4) comprising two electronically controllable switches (12) in series on either side of a second midpoint, the switches of this second arm being controlled according to a second duty cycle by the control unit, an inductive cell for contactless energy exchange consisting of the series combination of an inductor and a capacitor, this inductive cell being mounted between the first and second midpoints, the first (B1, B3) and second (B2, B4) arms being mounted in parallel,and the control unit (7p, 7s) being configured to act on the first and second duty cycles so that the voltage between the first and second midpoints (14, 15) emulates the presence of an inductor and / or a capacitor connected in series with the inductive cell (10, 20). Abbreviated figure: Fig. 1,

Description

Title of the invention: Power supply circuit for a vehicle electrical energy storage unit

[0001] The present invention relates to a contactless electrical power supply circuit for a vehicle electrical energy storage unit.

[0002] The electrical energy storage unit has, for example, a nominal voltage of 12V, 48V, 60V or more, for example greater than 300V, for example 400V, 800V or 1000V.

[0003] It is known to electrically power a vehicle electrical energy storage unit by contactless transmission using inductive coupling at a power of between 3 and 50 kW, when the vehicle is stationary or when it is moving. This power supply by contactless transmission is then carried out by means of distant electrical sub-circuits that are magnetically coupled and tuned to the same resonant frequency. The magnetically coupled sub-circuits each implement an LC-type resonant cell. However, to transmit a satisfactory power level, in particular several kW, it is necessary to operate at high frequencies, in particular of the order of 85 kHz or more, for the resonant frequency of each resonant sub-circuit. In addition, this type of solution requires operating at a short distance between the two sub-circuits.The frequency and power levels mentioned above, for implementation in kW, may also constitute a danger to the health of people exposed nearby, or a danger to the environment in general.

[0004] The solution according to the international application filed under No. PCT / EP2023 / 076297 on 09 / 22 / 2023 in the name of Valeo Systèmes de Contrôle Moteur, which is not part of the published state of the art, consists of applying an alternating voltage to the terminals of a primary inductive cell coupled by inductive coupling to a secondary inductive cell which, by impedance adaptation, makes it possible to transmit low-frequency electrical energy into an electrical energy storage unit, for example an electric vehicle battery.

[0005] There is a need to provide a power supply to an electrical energy storage unit by contactless transmission which further improves known solutions.

[0006] The invention aims to meet this need and achieves this, according to one of its aspects, using an electrical circuit comprising:

[0007] - two input terminals capable of being connected to a direct voltage,

[0008] - a control unit,

[0009] - a first switching arm, comprising two electronic switches com- commandable arranged on either side of a first midpoint, the switches of this first arm being controlled according to a first cyclic ratio by the control unit,

[0010] - a second switching arm, comprising two electronic switches controllable arranged on either side of a second midpoint, the switches of this second arm being controlled according to a second cyclic ratio by the control unit, and

[0011] - an inductive cell for contactless energy exchange by inductive coupling, consisting of the series connection of an inductor and a capacitor, this inductive cell being mounted between the first and second midpoints,

[0012] the first and second arms being mounted in parallel, and the control unit being configured to act on the first and second duty cycles so that the voltage between the first and second midpoints emulates the presence of at least one of an inductor and a capacitor mounted in series with the inductive cell.

[0013] Keeping a capacitor within the inductive cell makes it possible to improve the efficiency of the contactless energy exchange by inductive coupling and to maintain the voltage dynamics in the mesh in which the inductive cell is located, and the emulation of an inductor and / or a capacitor in series with the inductive cell makes it possible to vary the properties of the electrical circuit, in particular to take into account a misalignment between the inductive cell of this electrical circuit and the other inductive cell with which the contactless energy exchange by inductive coupling is carried out. Such a misalignment occurs, for example, when parking a vehicle for charging by contactless energy exchange by inductive coupling.

[0014] The voltage between the two midpoints thus corresponds to the voltage applied to the series connection of the inductive cell and at least one of a capacitor and an inductor.

[0015] According to one embodiment, the control unit is configured to act on the first and second duty cycles so that the voltage between the first and second midpoints emulates:

[0016] - the presence of an inductance connected in series with the inductive cell, and

[0017] - the presence of a capacitor connected in series with the inductive cell.

[0018] The voltage between the two midpoints then corresponds to the sum of the voltage across the inductive cell, a voltage across an inductor, and a voltage across a capacitor.

[0019] The control can be used to emulate an inductor and / or a capacitor whose value remains constant.

[0020] The control carried out by the control unit can make it possible, more broadly than a series connection of an inductance and / or a capacitor, to emulate the presence in series with the inductive cell of a complex impedance, such as an impedance with a negative inductance, an impedance with a capacitor of negative capacitance, or an impedance with an inductance of variable value over time or with a capacitor whose capacitance value varies over time.

[0021] The electrical circuit according to the invention may comprise a current sensor connected in series with the inductive cell. For example, the current sensor is arranged so that the connection between the first and second midpoints of the electrical circuit is constituted by the series connection of the inductive cell and the current sensor. As already indicated, the control carried out by the control unit allows the voltage between this first and second midpoint to also emulate the presence of an inductor and / or a capacitor connected in series with the inductive cell and the current sensor, although this inductor and / or this capacitor are not physically present.

[0022] According to a first variant of the invention, the two input terminals are connected to a voltage network via an AC / DC converter.

[0023] The electrical network provides, for example, a nominal effective voltage of 230V or 110V with a frequency of 50 Hz or 60 Hz. The electrical network is, for example, single-phase.

[0024] The electrical network is, for example, a regional or national electrical network. Alternatively, it may be an independent local network, comprising, for example, one or more batteries powered by energy sources such as wind turbines, solar panels, fuel cells or hydroelectric generators.

[0025] According to a second variant of the invention, the two input terminals of the electrical circuit are connected to an electrical energy storage unit.

[0026] Typically, the electrical energy storage unit may be a lithium-ion type battery. This battery has, for example, a nominal voltage of 12V, 48V, 60V or more, for example greater than 300V, for example 400V, 800V or 1000V.

[0027] The invention also relates to an electrical power supply circuit for an electrical energy storage unit, comprising:

[0028] - a first electrical circuit according to the invention, called “primary circuit”,

[0029] - a second electrical circuit according to the invention, called “secondary circuit”,

[0030] the primary sub-circuit and the secondary sub-circuit being configured so as to exchange electrical energy without contact by inductive coupling,

[0031] the control units of the primary circuit and of the secondary circuit being configured to act on the first and second duty cycles of each circuit so as to that :

[0032] - the voltage between the first and second midpoints of the primary circuit emulates the presence of an inductor and / or a capacitor connected in series with the primary inductive cell, and

[0033] - the voltage between the first and second midpoints of the secondary circuit emulates the presence of an inductor and / or a capacitor connected in series with the secondary inductive cell.

[0034] Advantageously, the invention makes it possible to simplify the electrical power supply circuit:

[0035] - by directly connecting the inductive cell to the converter in the primary circuit DC / AC formed by the two switching arms of the primary circuit and,

[0036] - by directly connecting the inductive cell to the adapter in the secondary circuit impedance formed by the two switching arms of the secondary circuit.

[0037] By adjusting the control laws of the DC / AC converter and the impedance adapter, it is possible to obtain a voltage between the first and second midpoints of the primary circuit, respectively secondary, behaving as if this voltage were applied to an assembly constituted by the primary inductive cell, respectively secondary, in series with an inductance and / or also in series with a capacitor.

[0038] Preferably, the first electrical circuit corresponds to an electrical circuit according to the first variant of the invention and the second electrical circuit corresponds to an electrical circuit according to the second variant of the invention.

[0039] Typically, the electrical power supply circuit according to the invention comprises an electrical energy storage unit mounted between the input terminals of the secondary circuit.

[0040] In order to allow a contactless exchange of electrical energy between the primary circuit and the secondary circuit, the inductive cell of the primary circuit and the inductive cell of the secondary circuit are configured so as to exchange electrical energy without contact by inductive coupling.

[0041] The primary inductive cell and the secondary inductive cell may have substantially the same resonant frequency.

[0042] Typically, the contactless exchange by inductive coupling of electrical energy takes place at a frequency lower than 5 kHz, for example lower than 3 kHz, or even lower than 2 kHz or 1 kHz, in particular still substantially equal to 400 Hz or 50 Hz.

[0043] In such a case, the inductance of each inductive cell may be made of metal wire, such as copper. Such metal wire is solid, as opposed to Litz wire. A solid metal wire does not have its cross-section hollowed out. Alternatively, this inductance of the secondary inductive cell is made of Litz wire.

[0044] Alternatively, the contactless exchange by inductive coupling of electrical energy can be done at a frequency of 85 kHz. In this variant, Litz wire is advantageously used to produce each inductance of one of the inductive cells.

[0045] The two switching arms of the secondary circuit may define a system performing an impedance matching of the impedance on the AC input of the system, independently of the impedance of the electrical energy storage unit, the secondary control unit being configured to control one of these two arms so that it switches at the frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle of 50%, and to control the other of these two arms so that it switches at a frequency higher than that of said electrical energy and with a duty cycle modulated according to the AC current flowing in the secondary inductive cell and the voltage on the AC input of this impedance matching system.

[0046] In such a case, the capacitance of the capacitor produced by emulation can first be fixed by the control to a first value obtained from the nominal values ​​of the physical components of the electrical circuit and from the frequency at which the exchange of electrical energy takes place without contact by inductive coupling.

[0047] In the case of control of the two switching arms by phase shift, the control can also be such that the capacitance of the capacitor produced by emulation takes a second value while the equivalent impedance value on the AC input of the impedance matching system is low. Then, the capacitance of the capacitor produced by emulation can vary from the second value, to increase the transmitted power. Finally, the capacitance of the capacitor produced by emulation being fixed, the equivalent impedance value on the AC input of the impedance matching system can be increased to achieve an optimum transmitted power.

[0048] In all of the above, the control units may be configured to control the various switching arms so as to selectively perform:

[0049] - a charge of the electrical energy storage unit from the voltage network, Or

[0050] - a load of the voltage network from the electrical energy storage unit.

[0051] Thus, depending on the need, the exchange of electrical energy can be carried out in one direction or the other.

[0052] In all of the above, each controllable electronic switch is for example a transistor, for example bipolar, MOS or IGBT, or a thyristor. Each controllable electronic switch is for example bidirectional.

[0053] In all of the above, each control unit may be a digital processing circuit, for example an ASIC type integrated circuit (“Application-specific integrated circuit”). integrated circuit" in English) or a microcontroller.

[0054] Alternatively, a single control unit, for example a digital processing circuit, may be provided, this control unit controlling the switching arms of the primary circuit and the secondary circuit.

[0055] As a further variant, the control unit is common to the primary circuit and to the secondary circuit, and it comprises a primary circuit control module and a secondary circuit control module.

[0056] The invention also relates, according to another of its aspects, to a component for the electrical power supply of an electrical energy storage unit, comprising the electrical circuit as defined above, the component defining in particular a structure rigidly supporting the primary circuit and the secondary circuit coupled together. Such a component is commonly called an “on-board charger”. This component is capable of being embedded in a hybrid or electric vehicle.

[0057] The invention also relates, according to another of its aspects, to a device for supplying electricity to an electrical energy storage unit, comprising:

[0058] - a charging terminal for a hybrid or electric vehicle, in which is arranged the primary circuit of the electrical circuit as defined above or to which this primary circuit is electrically connected, and

[0059] - a component capable of being embedded in a hybrid or electric vehicle, in in which the secondary circuit of the electrical circuit as defined above is arranged.

[0060] This terminal then receives electrical energy from an electrical network via a cable which can be a single-phase cable or a three-phase cable. In this case, the primary circuit and the secondary circuit are not integrated into the same physical component.

[0061] The invention also relates, according to another of its aspects, to a method for charging a vehicle electrical energy storage unit by contactless energy exchange by inductive coupling using an electrical circuit comprising:

[0062] - two input terminals capable of being connected to a direct voltage,

[0063] - a first switching arm, comprising two electronic switches com- controllable arranged on either side of a first midpoint, the switches of this first arm being controlled according to a first cyclic ratio,

[0064] - a second switching arm, comprising two electronic switches controllable arranged in series on either side of a second midpoint, the switches of this second arm being controlled according to a second cyclic ratio, and

[0065] - an inductive cell for contactless energy exchange by inductive coupling consisting of the series connection of an inductor and a capacitor, this inductive cell being mounted between the first and second midpoints,

[0066] the first and second arms being mounted in parallel,

[0067] method according to which the first and second duty cycles are acted on so that the voltage between the first and second midpoints emulates the presence of at least one of an inductor and a capacitor mounted in series with the inductive cell.

[0068] For example, the first and second duty cycles are acted upon so that the value of the inductance and / or the capacitance of the capacitor whose presence is emulated varies as a function of the transfer of electrical energy to charge the electrical energy storage unit. As already mentioned:

[0069] - for example, we act on these cyclic ratios to fix the capacity of the capacitor produced by emulation at a first value obtained from the nominal values ​​of the physical components of the electrical circuit and from the frequency at which the exchange of electrical energy takes place without contact by inductive coupling,

[0070] - then the two switching arms are controlled by phase shift and action is taken on the cyclic ratios to fix the capacitance of the capacitor made by emulation takes a second value while the equivalent impedance value on the AC input of the impedance matching system is low, then

[0071] - we act on the cyclic ratios to vary the capacitance of the capacitor carried out by emulation, in order to increase the transmitted power.

[0072] The invention may be better understood by reading the following description of a non-limiting example of its implementation and by examining the attached drawing in which:

[0073] [Fig.l] schematically represents an electrical circuit according to an exemplary implementation of the invention.

[0074] [Fig.l] shows a circuit 1 for supplying electricity to an electrical energy storage unit 2. This electrical energy storage unit 2 is, for example, a vehicle battery, which may have a nominal voltage of 48V, 60V, 300V, 400V, 800V or more. This battery is used to supply an electric or hybrid vehicle propulsion system.

[0075] This electrical power supply circuit 1 comprises:

[0076] - a primary circuit 4, connected to a voltage network 5, and

[0077] - a secondary circuit 6, connected to the electrical energy storage unit 2.

[0078] The electrical power supply circuit 1 implements a contactless exchange of electrical energy by inductive coupling between the primary circuit 4 and the secondary circuit 6, for charging the electrical energy storage unit 2.

[0079] In the example considered, the primary circuit 4 comprises:

[0080] - two input terminals 13 connected to an AC / DC converter 9 itself connected on a 5 voltage network,

[0081] - a 7p primary control unit,

[0082] - a first switching arm B1, comprising two electronic switches controllable 12 arranged on either side of a first midpoint 14, the switches of this first arm being controlled according to a first cyclic ratio api by the primary control unit 7p,

[0083] - a second switching arm B2, comprising two electronic switches controllable 12 arranged on either side of a second midpoint 15, the switches of this second arm being controlled according to a second cyclic ratio ap2 by the primary control unit 7p,

[0084] - a primary inductive cell 10 for contactless energy exchange by coupling inductive cell constituted here by the series connection of an inductance and a capacitor, this primary inductive cell 10 being connected between the first 14 and second 15 midpoints.

[0085] As shown in [Fig.l], the first B1 and second B2 switching arms are mounted in parallel.

[0086] The electrical network 5 provides, for example, a nominal effective voltage of 230V with a frequency of 50 Hz or 60 Hz. The electrical network 5 is here single-phase, so that the voltage across the terminals of the AC / DC converter 9 is also single-phase.

[0087] Each switching arm B1 and B2 of the primary circuit 4 here comprises two controllable electronic switches 12 connected in series, such as MOS, IGBT or bipolar transistors, or thyristors.

[0088] The first arm B1 thus comprises two controllable electronic switches 12 in series between which a first terminal of the primary inductive cell 10 for the contactless exchange of energy is connected.

[0089] The second arm B2 thus comprises two controllable electronic switches 12 in series between which a first terminal of the primary inductive cell 10 for contactless energy exchange is connected.

[0090] The AC / DC converter 9 is mounted in parallel with these two arms B1 and B2.

[0091] According to the embodiment shown in [Fig.l], the primary circuit 4 comprises a primary current sensor 8p mounted in series with the primary inductive cell 10. This primary current sensor can advantageously send information on the measured current to the primary control unit 7p.

[0092] The primary control unit 7p is here configured to act on the first api and second ap2 duty cycles so that the voltage between the two midpoints 14, 15 of the primary circuit 4 emulates the presence of an inductor and / or a capacitor mounted in series with the primary inductive cell 10. In a preferred example, this control is such that the presence of an inductor and a capacitor mounted in series with the primary inductive cell 10 is emulated.

[0093] We will now describe an example of secondary circuit 6 with reference to [Fig.l]

[0094] In the example considered, the secondary circuit 6 comprises:

[0095] - a secondary inductive cell 20 for contactless energy exchange by inductive coupling, constituted here by the series connection of an inductor and a capacitor,

[0096] - an AC / DC converter 23 capable of carrying out an adaptation of the impedance equivalent on its alternating input (therefore on the side of the secondary inductive cell 20), so as to vary this impedance independently of the impedance of the electrical energy storage unit 2, and

[0097] - a secondary control unit 7s.

[0098] As shown in [Fig.l], the AC / DC converter 23 comprises:

[0099] - a first switching arm B3, comprising two electronic switches controllable 12 arranged on either side of a first midpoint 14, the switches of this first arm being controlled according to a first cyclic ratio as[ by the secondary control unit 7s,

[0100] - a second switching arm B4, comprising two electronic switches controllable 12 arranged on either side of a second midpoint 15, the switches of this second arm being controlled according to a second cyclic ratio as2 by the secondary control unit 7s.

[0101] As illustrated in [Fig.l], the first B3 and second B4 switching arms are mounted in parallel and the secondary inductive cell 20 is mounted between the two midpoints 14, 15 of the AC / DC converter 23.

[0102] The secondary control unit 7s is configured to act on the first and second duty cycles so that the voltage between the first 14 and the second 15 midpoint of the secondary circuit 6 emulates the presence of an inductor and / or a capacitor connected in series with the secondary inductive cell 20. In a preferred example, this control is such that the presence of an inductor and a capacitor connected in series with the secondary inductive cell 20 is emulated.

[0103] According to an embodiment shown in [Fig.l], the secondary circuit 6 comprises a secondary current sensor 8s mounted in series with the secondary inductive cell 20. This secondary current sensor can advantageously send information on the measured current to the secondary control unit 7s.

[0104] The AC / DC converter 23 of [Fig.l] is for example controlled as follows by the secondary control unit 7s, to carry out the impedance adaptation on the alternating input of this converter 23:

[0105] -one of the two arms B3 or B4 switches at the frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle of 50%, and

[0106] - the other of the two arms B3 or B4 switches at a frequency higher than that of the electrical energy exchanged without contact by inductive coupling, for example at least 5 times or 10 times the frequency of this energy, and with a duty cycle a; modulated according to the alternating current flowing in the secondary inductive cell 20 and according to the voltage at the terminals of the alternating input of the AC / DC converter 23. The duty cycle asi is expressed using the following expression where i is 1 or 2:

[0107] œsi=(RRef xlll) / Vbatt

[0108] where:

[0109] - Vbatt denotes the voltage across the electrical energy storage unit 2,

[0110] -1 denotes the current flowing in the secondary inductive cell 20,

[0111] - RRef is the equivalent impedance on the AC input of the inverter / rectifier, R Ref being equal to the ratio V / I where V is the voltage between the two midpoints 14, 15 of the AC / DC converter 23.

[0112] Due to the voltage (api-ap2)*Vdc, with Vdc the voltage between the two input terminals 13 of the primary circuit, the primary control unit 7p makes it possible to emulate the presence between the first 14 and the second 15 midpoint of the switching arms B1 and B2 of an inductor and a capacitor in series with the primary inductive cell 10.

[0113] Furthermore, with (as[ - as2)*Vbatt, it is possible to emulate the presence between the first 14 and the second 15 midpoint of the switching arms B3 and B4 of a capacitor and an inductor in series with the secondary inductive cell 20.

[0114] For example, it is possible to act on the control in order to vary the capacity of the emulated capacitor during charging to increase the power transferred between the primary circuit 4 and the secondary circuit 6.

[0115] The invention has been described above with the help of embodiments shown in the figure, without limitation of the general inventive concept.

[0116] Thus, although each switching arm B3, B4 comprises two controllable electronic switches 12, the invention also applies when only one electronic switch 12 is controllable, per switching arm B3 or B4.

[0117] In this case, each switching arm B3, B4 then comprises, for example, two electronic switches arranged on either side of its midpoint 14, 15:

[0118] - a controllable electronic switch 12 between the midpoint 14, 15 and the negative terminal of the electrical energy storage unit 2, and

[0119] - a diode between the midpoint 14, 15 and the positive terminal of the storage unit of electrical energy 2.

[0120] Furthermore, although two separate control units are mentioned in the described example, namely: the primary control unit 7p and the control unit se secondary circuit 7s, a single control unit can be used, the latter including, where appropriate, a control module dedicated to controlling the primary circuit 4 and a control module dedicated to controlling the secondary circuit 6.

[0121] Many other modifications and variations suggest themselves to those skilled in the art, after reflection on the different embodiments illustrated in this application.

[0122] These embodiments are given by way of example and are not intended to limit the scope of the invention, which is determined exclusively by the claims below.

[0123] In the claims, the word "comprising" does not exclude other elements or steps, and the use of the indefinite article "a" or "an" does not exclude a plurality.

[0124] The mere fact that different features are recited in mutually dependent claims does not indicate that a combination of these features cannot be advantageously used. Finally, any reference used in the claims should not be interpreted as a limitation of the scope of the invention.

Claims

Claims

1. Electrical circuit (4, 6) comprising: - two input terminals (13) capable of being connected to a direct voltage, - a control unit (7p, 7s) - a first switching arm (Bl, B3), comprising two controllable electronic switches (12) arranged on either side of a first midpoint (14), the switches of this first arm being controlled according to a first duty cycle by the control unit, - a second switching arm (B2, B4), comprising two controllable electronic switches (12) arranged on either side of a second midpoint (15), the switches of this second arm being controlled according to a second duty cycle by the control unit, - an inductive cell (10, 20) for the contactless exchange of energy by inductive coupling, constituted by the series association of an inductor and a capacitor, this inductive cell (10,20) being mounted between the first and second midpoints (14, 15), the first (B1, B3) and second (B2, B4) arms being mounted in parallel, and the control unit (7p, 7s) being configured to act on the first and second duty cycles so that the voltage between the first and second midpoints (14, 15) emulates the presence of at least one of an inductor and a capacitor mounted in series with the inductive cell (10, 20).,

2. Electrical circuit according to claim 1, the control unit being configured to act on the first and second duty cycles so that the voltage between the first and second midpoints (14, 15) emulates: the presence of an inductor connected in series with the inductive cell (10, 20), and the presence of a capacitor connected in series with the inductive cell (10, 20).

3. Electrical circuit according to one of the preceding claims, in which a current sensor (8p, 8s) is connected in series with the inductive cell (10, 20).

4. Electrical circuit according to claim 3, the assembly between the first (14) and second (15) midpoints being constituted by the series association of the inductive cell (10, 20) and the current sensor.

5. An electrical circuit according to any preceding claim, comprising an AC / DC converter via which the two input terminals (13) are adapted to be connected to a voltage network (5).

6. Electrical circuit according to one of claims 1 to 4, wherein the two input terminals (13) are connected to an electrical energy storage unit (2).

7. Electrical power supply circuit for an electrical energy storage unit (2), comprising: - an electrical circuit (4) according to any one of claims 1 to 5, called the "primary circuit", and - an electrical circuit (6) according to one of claims 1 to 4 or 6, called the "secondary circuit", the primary sub-circuit (4) and the secondary sub-circuit (6) being configured to exchange electrical energy without contact by inductive coupling, the control units of the primary circuit and the secondary circuit being configured to act on the first and second duty cycles of each circuit so that: - the voltage between the first (14) and second (15) midpoints of the primary circuit (4) emulates the presence in series with the inductive cell (10) of the primary circuit (4) of at least one of a capacitor and an inductor,and - the voltage between the first (14) and second (15) midpoints of the secondary circuit (6) emulates the presence in series with the inductive cell (20) of the secondary circuit (6) of at least one of a capacitor and an inductor.,

8. An electrical circuit according to claim 7, comprising an electrical energy storage unit (2) mounted between the input terminals (13) of the secondary circuit (6).

9. Electrical circuit according to claim 8, the contactless exchange by inductive coupling of electrical energy taking place at a frequency of less than 5 kHz.

10. Device for supplying electricity to a storage unit of electrical energy (2), comprising: - an electrical circuit according to any one of claims 7 to 9, - a charging terminal for a hybrid or electric vehicle, in which the primary circuit (4) of the electrical circuit (1) is arranged or to which this primary circuit (4) is electrically connected, and - a component capable of being embedded in a hybrid or electric vehicle, in which the secondary circuit (6) of the electrical circuit (1) is arranged.

11. A method of charging a vehicle electrical energy storage unit by contactless energy exchange by inductive coupling using an electrical circuit (4, 6) comprising: - two input terminals (13) capable of being connected to a direct voltage, - a first switching arm (B1, B3), comprising two controllable electronic switches (12) in series on either side of a first midpoint (14), the switches of this first arm being controlled according to a first duty cycle, - a second switching arm (B2, B4), comprising two controllable electronic switches (12) in series on either side of a second midpoint (15), the switches of this second arm being controlled according to a second duty cycle, and - an inductive cell (10, 20) for the contactless exchange of energy by inductive coupling constituted by the series association of an inductor and a capacitor, this inductive cell (10, 20) being mounted between the first and second midpoints (14, 15), the first (B1, B3) and second (B2, B4) arms being mounted in parallel, method according to which the first and second duty cycles are acted on so that the voltage between the first and second midpoints (14, 15) emulates the presence of at least one of an inductor and a capacitor mounted in series with the inductive cell (10, 20).

12. Method according to claim 11, in which the first and second duty cycles are acted on so that the value of the inductance and / or the capacitance of the capacitor whose presence is emulated varies as a function of the transfer of electrical energy to charge the electrical energy storage unit.

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