Electrical power supply circuit for a vehicle electrical energy storage unit

Abstract

The invention relates to an electrical circuit (6) comprising: - two input terminals (13) capable of being connected to a DC voltage; - a control unit (7p, 7s); - a first switching arm (B1, B3) comprising two controllable electronic switches (12) in series on either side of a first midpoint, the switches in 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) in series on either side of a second midpoint, the switches in this second arm being controlled according to a second duty cycle by the control unit; - an inductive cell (10, 20) for contactless energy exchange consisting of an inductor, the inductive cell being mounted between the first and second midpoints (14, 15), the first (B1, B3) and second (B2, B4) arms being mounted in parallel, the circuit comprising a filtering cell (11, 21) for filtering out common-mode and / or differential-mode noise.

Description

[0001] Power supply circuit of a vehicle electrical energy storage unit

[0002] The present invention relates to a contactless power supply circuit for a vehicle electrical energy storage unit.

[0003] 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

[0004] It is known to electrically power a vehicle's 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 contactless transmission power supply is then carried out by means of magnetically coupled remote electrical sub-circuits tuned to the same resonant frequency. The magnetically coupled sub-circuits each implement an LC-type resonant cell.

[0005] The solution according to the application filed in France under No. 22 09978 on 09 / 30 / 2022 which is not part of the 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.

[0006] In this solution, it is necessary to adapt the behavior of the inductive cells by putting large passive capacitive and inductive components in order to operate at low frequencies. These components are expensive, very large especially for very low frequencies such as frequencies lower than or equal to 1000Hz, and have an equivalent series resistance ("ESR" in English) whose values ​​can create parasitic behaviors likely to affect the efficiency of the transfer of electrical energy.

[0007] The invention aims to enable low-frequency inductive charging without the drawbacks mentioned above and it relates, according to one of its aspects, to an electrical circuit comprising:

[0008] - two input terminals suitable for connection to a direct voltage,

[0009] - a control unit, - a first switching arm, comprising two electronic switches controllable in series 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 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,

[0011] - an inductive cell for contactless energy exchange constituted by an inductor, the inductive cell being mounted between the first and second midpoints, the first and second arms being mounted in parallel, the control unit being configured to act on the first and second duty cycle so that the voltage between the first and second midpoints emulates the presence of an inductor and a capacitor mounted in series with the inductive cell, the circuit comprising a cell for filtering common mode noise and / or differential mode noise, this cell comprising:

[0012] - two magnetically coupled inductors, each inductor being arranged in series between a midpoint of a switching arm and a terminal of the inductive cell, and

[0013] - at least one of a capacitor arranged in parallel with the inductive cell and a capacitor arranged between a terminal of the inductive cell and the earth.

[0014] The circuit as defined above allows, by controlling the switching arms, to eliminate a capacitor and a physical inductance while obtaining an electrical behavior equivalent to the presence of these physical components. The invention thus takes advantage of the presence of an existing voltage converter to add an additional function to this voltage converter. This reduces the costs and size of the circuit.

[0015] However, the suppression of these physical components by switching the switching arms can cause the propagation, even at low levels, of high-frequency components in the voltage across the inductive cell, this propagation being done in a differential mode and a common mode and generating parasites.

[0016] The circuit as defined above then also makes it possible, by the presence of the common mode noise and / or differential mode noise filtering cell, to overcome the drawback linked to the elimination of the inductor and capacitor which are now emulated. The invention therefore makes it possible to eliminate the bulky capacitor and inductor whose behaviors are emulated and to filter high frequencies by using smaller and less expensive inductors and one or more capacitors. The capacitor and inductor replaced by an emulation would for example have had values ​​whose product is at least 5 times greater, in particular at least 10 times greater, than the product of an inductor and a capacitor of the common mode noise and / or differential mode noise filtering cell.For example, the capacitor and inductor replaced by an emulation would have had values ​​whose product is at least 5 times greater, including at least 10 times greater, than the product of any inductor and capacitor in the common mode noise and / or differential mode noise filter cell.

[0017] The two magnetically coupled inductances are obtained, for example, by two electrical windings around the same magnetic core. Other ways to obtain two magnetically coupled inductances are possible.

[0018] The command can emulate an inductor and a capacitor whose value remains constant.

[0019] The control carried out by the control unit can allow, more broadly than a series connection of an inductor and a capacitor, to emulate the presence in series with the inductive cell of a complex impedance, such as an impedance with a negative inductance, such as an impedance with a capacitor of negative capacitance, or such as an impedance with an inductor of variable value over time or with a capacitor whose capacitance value varies over time.

[0020] The voltage between the two midpoints can correspond to the voltage applied to the series assembly comprising:

[0021] - the inductive cell,

[0022] - an emulated inductance,

[0023] - an emulated capacitor, and

[0024] - two inductances in magnetic coupling of the filter cell.

[0025] 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 comprises the series connection of the inductive cell, the current sensor and the two inductors in coupling with the filter cell, the latter framing the inductive cell and the current sensor. This series branch also comprises the emulated inductor and the emulated capacitor.

[0026] According to a first variant of the invention, the two input terminals are connected to a voltage network via an AC / DC converter. According to this first variant, the two switching arms define a DC / AC converter allowing the presence of an alternating voltage at the terminals of the inductive cell.

[0027] 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.

[0028] The power grid is, for example, a regional or national power grid. Alternatively, it may be an independent local network, for example, comprising one or more batteries powered by energy sources such as wind turbines, solar panels, fuel cells, or hydroelectric generators.

[0029] According to a second variant of the invention, the two input terminals of the electrical circuit are connected to an electrical energy storage unit. According to this second variant, the two switching arms define a DC / AC converter allowing impedance matching on its AC input independently of the impedance of the electrical energy storage unit. This impedance matching can be carried out as follows:

[0030] - one of the first and second switching arms switches at the frequency of the energy exchanged without contact, and

[0031] - the other of the first and second arms can switch at a higher frequency, for example equal to or greater than 5 times or 10 times the frequency of the energy exchanged without contact. One of the switching arms switches, for example, at the frequency of the energy exchanged without contact with a duty cycle of 50%, and the other switching arm switches at a frequency equal to or greater than that of the energy transmitted from the primary circuit, in particular equal to or greater than 5 times or 10 times the frequency of the energy transmitted from the primary circuit, and with a duty cycle modulated according to the measured alternating current and the voltage on the alternating input of the two switching arms. This embodiment of impedance matching by the two switching arms of the DC / AC converter is, for example, as described in the Applicant's application FR 3 140 490.The contents of that application are incorporated by reference into the present application, with respect to the manner of driving two switching arms between the midpoints of which an inductive cell is mounted to perform impedance matching.

[0032] Typically, the electrical energy storage unit may be a lithium-ion 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.

[0033] The filtering cell may be a common mode noise and differential mode noise filtering cell. Such a cell comprises, in addition to the two aforementioned magnetically coupled inductors,

[0034] - a first capacitor arranged in parallel with the inductive cell,

[0035] - a second capacitor arranged between a first terminal of the inductive cell and the ground, and

[0036] - a third capacitor placed between a second terminal of the inductive cell and the ground.

[0037] When the first and second capacitors are present and the third capacitor is absent, the two capacitors present can already provide differential filtering. In this case, this differential filtering may not require the presence of the third capacitor.

[0038] When the aforementioned current sensor is connected in series with the inductive cell, the first capacitor can be connected in parallel with the series connection of the current sensor and the inductive cell. Also in this case, this current sensor can be mounted between the inductive cell and the connection to the second or third capacitor.

[0039] Typically, the capacitance of the first capacitor is less than or equal to 1 mF and greater than or equal to 10 nF, and the capacitance of the second capacitor and / or the third capacitor is less than or equal to 1 mF and greater than or equal to 10 nF.

[0040] Since the capacitances are low, the second and third capacitors can be Y-type capacitors. The first capacitor is, for example, an X-type capacitor.

[0041] Typically, each of the filter cell inductances has a value less than or equal to 1 mH and greater than or equal to 100 nH.

[0042] Typically, the magnetic coupling rate between the two inductances of the filter cell can take any value between 0 and 100%, terminals included.

[0043] The invention also relates to an electrical power supply circuit for an electrical energy storage unit, comprising:

[0044] - a first circuit as above, called the “primary circuit”, - a second circuit as above, called the “secondary circuit”, 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:

[0045] - the voltage between the first and second midpoints of the primary circuit emulates the presence of an inductor and a capacitor connected in series with the primary inductive cell, and

[0046] - the voltage between the first and second midpoints of the secondary circuit emulates the presence of an inductor and a capacitor connected in series with the secondary inductive cell, the inductive cell of the primary circuit and the inductive cell of the secondary circuit being configured so as to exchange electrical energy without contact by inductive coupling.

[0047] By adjusting the control laws of the DC / AC converter of the primary circuit, respectively of the secondary circuit, 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 comprising the primary inductive cell, respectively secondary, in series with an inductance and also in series with a capacitor, in addition to the presence of the common mode noise and / or differential mode noise filtering cell.

[0048] Such a circuit therefore makes it possible to eliminate the bulky capacitor and inductor whose behaviors are emulated and to filter high frequencies by using smaller and less expensive inductors and one or more capacitors.

[0049] In order to enable 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 to exchange electrical energy without contact by inductive coupling.

[0050] Where appropriate, these physical coils and the components whose behavior is emulated are chosen so that the inductive cell of the primary circuit and the inductive cell of the secondary circuit have substantially the same resonant frequency.

[0051] The contactless exchange by inductive coupling of electrical energy is carried out, for example, at a frequency of less than 10 kHz, for example 7 kHz, for example 5 kHz, for example less than 3 kHz, or even less than 2 kHz or 1 kHz, in particular still substantially equal to 400 Hz or 50 Hz. Alternatively, the contactless exchange by inductive coupling of electrical energy can be carried out at a frequency of 85 kHz.

[0052] In all of the above, the control units can be configured to control the different switching arms so as to selectively achieve:

[0053] - a charge of the electrical energy storage unit from the voltage network, or

[0054] - a load of the voltage network from the electrical energy storage unit.

[0055] Thus, depending on the need, the exchange of electrical energy can take place in one direction or the other.

[0056] 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.

[0057] In all of the above, each control unit can be a digital processing circuit, for example an ASIC (Application-specific integrated circuit) or a microcontroller.

[0058] 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.

[0059] Alternatively, the control unit is common to the primary circuit and the secondary circuit, and it comprises a primary circuit control module and a secondary circuit control module.

[0060] 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 together. Such a component is commonly called an "on-board charger". This component is capable of being embedded in a hybrid or electric vehicle.

[0061] The invention also relates, according to another of its aspects, to a device for supplying electricity to an electrical energy storage unit, comprising:

[0062] - a charging terminal for a hybrid or electric vehicle, in which the primary circuit of the electrical circuit as defined above is arranged or to which is connected, and

[0063] - a component capable of being embedded in a hybrid or electric vehicle, in which the secondary circuit of the electrical circuit as defined above is arranged.

[0064] 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.

[0065] 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:

[0066] [Fig. l] schematically represents an electrical circuit according to an exemplary implementation of the invention.

[0067] [Fig.2] schematically represents an electrical circuit comprising the inductive and capacitive components that the present invention makes it possible to emulate.

[0068] Figure 1 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 power to an electric or hybrid vehicle propulsion system.

[0069] This power supply circuit 1 includes:

[0070] - a primary circuit 4, connected to a voltage network 5, and

[0071] - a secondary circuit 6, connected to the electrical energy storage unit 2.

[0072] The 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.

[0073] In the example considered, the primary circuit 4 comprises:

[0074] - two input terminals 13 connected to an AC / DC converter 9 itself connected to a voltage network 5,

[0075] - a 7p primary control unit,

[0076] - a first switching arm Bl, 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 cyclic ratio api by the primary control unit 7p,

[0077] - a second switching arm B2, 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 ap2 by the primary control unit 7p,

[0078] - a primary inductive cell 10 for contactless energy exchange constituted here by an inductance, being mounted between the first 14 and second 15 midpoints. As shown in Figure 1, the first B1 and second B2 switching arms are mounted in parallel.

[0079] For example, the electrical network 5 provides a nominal effective voltage of 230V with a frequency of 50 Hz or 60 Hz. The electrical network 5 is single-phase here, so that the voltage across the AC / DC converter 9 is also single-phase.

[0080] 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.

[0081] 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 contactless energy exchange is connected.

[0082] 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.

[0083] The two arms B1 and B2 are cascaded with the AC / DC converter 9.

[0084] According to the embodiment shown in Figure 1, the primary circuit 4 comprises a primary current sensor 8p connected in series with the primary inductive cell 10. This primary current sensor 8p can advantageously send information on the measured current to the primary control unit 7p.

[0085] 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 a capacitor connected in series with the primary inductive cell 10.

[0086] The primary inductive cell 10 is here constituted by a coil allowing the generation of magnetic energy. The control of the duty cycles by the primary control unit 7p makes it possible to emulate the behavior of a capacitor, thus forming a resonant cell. The coil has for example an inductance of between ImH to lOOmH and the capacitor whose behavior is emulated by the control of the duty cycles by the primary control unit 7p has a capacitance of between lOOpF and lOOmF.

[0087] As shown in Figure 1, the primary circuit also comprises a filtering cell 11, which in the example considered filters the common mode noise and the differential mode noise.

[0088] This filtering cell 11 here comprises: - two inductances 17a, 17b in magnetic coupling, each inductance being arranged in series between a midpoint 14, 15 of a switching arm and a terminal of the inductive cell 10,

[0089] - a first capacitor 16 arranged in parallel with the inductive cell 10,

[0090] - a second capacitor 18a arranged between a first terminal of the inductive cell 10 and the earth,

[0091] - a third capacitor 18b placed between the primary current sensor 8p and earth.

[0092] In the example considered, the capacitance of the first capacitor 16 is less than or equal to 1 mF and greater than or equal to 10 nF and this capacitor is a type X capacitor. Still in this example, the capacitance of the second capacitor 18a and that of the third capacitor 18b is less than or equal to 1 mF and greater than or equal to 10 nF, and these capacitors are type Y.

[0093] Still in this example, the inductances 17a, 17b of the filtering cell 11 each have, for example, a value less than or equal to 1 mH and greater than or equal to 100 nH.

[0094] We will now describe an example of secondary circuit 6 with reference to figure 1. In the example considered, secondary circuit 6 comprises:

[0095] - a secondary inductive cell 20 for contactless energy exchange constituted here by an inductance,

[0096] - an AC / DC converter 23 capable of carrying out an adaptation of the equivalent impedance 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 7s secondary control unit.

[0098] As shown in Figure 1, the AC / DC converter 23 comprises:

[0099] - a first switching arm 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 asl by the secondary control unit 7s,

[0100] - a second switching arm 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 as2 by the secondary control unit 7s. As illustrated in Figure 1, 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.

[0101] The AC / DC converter 23 of Figure 1 is for example controlled as follows by the secondary control unit 7s, to carry out the impedance adaptation on the AC input of this converter 23:

[0102] - one of the two arms B3 or B4 switches at the frequency of the energy exchanged without contact and with a duty cycle of 50%, and

[0103] - the other of the two arms B3 or B4 switches at a frequency higher than that of the energy exchanged without contact, for example at least 5 times or 10 times the frequency of the energy exchanged without contact, and with a duty cycle modulated according to the alternating current measured at the output of the secondary inductive cell 20 and according to the voltage at the terminals of the alternating input of the AC / DC converter 23.

[0104] 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 a capacitor connected in series with the secondary inductive cell 20.

[0105] Advantageously, the electrical circuit according to the invention makes it possible to obtain, by controlling the switching arms B1 to B4, an effect equivalent to the electrical circuit illustrated in Figure 2, this effect being obtained according to the invention in the absence of the capacitors Cp and Cs as well as the inductances Lp2 and Ls2 of Figure 2.

[0106] In the circuit shown in Figure 2, the primary circuit 4 has, between its two midpoints 14 and 15, the series association of a primary impedance Zp and a primary inductive cell Lpl. The primary impedance Zp here comprises in series an inductance Lp2 and a capacitance Cp.

[0107] In the circuit shown in Figure 2, the secondary circuit 6 has, between its two midpoints 14 and 15, the series association of a secondary impedance Zs and a secondary inductive cell Lsl. The secondary impedance Zs here comprises in series an inductance Ls2 and a capacitance Cs.

[0108] The coupling between the primary and secondary inductive cells allows a contactless transmission of electrical energy between the primary and secondary circuit. Advantageously, the electrical circuit according to the invention, as for example shown in Figure 1, allows, using the switching arms already present in the circuit according to the prior art, to emulate: - the presence of the primary impedance Zp in series with the primary inductive cell 10 on the primary circuit side, and

[0109] - the presence of the secondary impedance Zs in series with the secondary inductive cell 20 on the secondary circuit side, without physically having the components of the primary and secondary impedances.

[0110] Due to the voltage (apl-ap2)*Vdc, with Vdc the voltage between the two input terminals 13 of the primary circuit, the primary control unit 7p allows 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.

[0111] In accordance with the above, between the first 14 and the second 15 midpoint of the switching arms B1 and B2 of the primary circuit 4 there is an assembly comprising in series: the primary inductive cell 10, the current sensor 8p and the two coupled inductances 17a and 17b of the filter cell 11, the latter framing the primary inductive cell 10 and the current sensor 8p. This assembly also comprises in series with the aforementioned components the emulated inductance and the emulated capacitor, although these emulated components are not visible in Figure 1.

[0112] Furthermore, with (asl - as2)*Vbatt, with Vbatt the voltage across the electrical energy storage unit 2, it is possible to emulate the presence between the first 14 and second 15 midpoint of the switching arms B3 and B4 of a capacitor and an inductor in series with the secondary inductive cell 20.

[0113] In accordance with the above, between the first 14 and the second 15 midpoint of the switching arms B3 and B4 of the secondary circuit 6 there is an assembly comprising in series: the secondary inductive cell 20, the current sensor 8s and the two coupled inductances 24a and 24b of the filter cell 21, the latter framing the primary inductive cell 20 and the current sensor 8s. This assembly also comprises in series with the aforementioned components the emulated inductance and the emulated capacitor, although these emulated components are not visible in Figure 1.

[0114] Advantageously, the physical coils in the inductive cells are determined so as to maximize the coupled inductance value since the uncoupled parts of these inductances that can be used in resonance are emulated by the control units of the primary and secondary circuits.

[0115] The invention has been described above with the help of embodiments shown in the figure, without limitation of the general inventive concept. Many other modifications and variations suggest themselves to those skilled in the art, after reflection on the various embodiments illustrated in this application.

[0116] 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.

[0117] 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.

[0118] 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 construed as a limitation of the scope of the invention.

Claims

Claims 1. Electrical circuit (4, 6) comprising: two input terminals capable of being connected to a direct voltage, - a control unit (7p, 7s) - 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 cyclic ratio by the control unit - 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 by the control unit, - an inductive cell (10, 20) for contactless energy exchange constituted by an inductance, the 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, the control unit (7p, 7s) being configured to act on the first and second duty cycle so that the voltage between the first and second midpoints (14, 15) emulates the presence of an inductance and a capacitor mounted in series with the inductive cell (10, 20), wherein the circuit comprises a filtering cell (11, 21) for common mode noise and / or differential mode noise, this cell comprising: two magnetically coupled inductances (17a, 17b, 24a, 24b), each inductance being arranged in series between a midpoint (14, 15) of a switching arm and a terminal of the inductive cell (10, 20), and at least one of a capacitor (16,26) arranged in parallel with the inductive cell and a capacitor (18a, 18b, 28a, 28b) arranged between a terminal of the inductive cell and the ground., 2. Electrical circuit according to claim 1, in which the filtering cell (11, 21) is a cell for filtering common mode noise and differential mode noise, the cell comprising: a first capacitor (16, 26) arranged in parallel with the inductive cell (10, 20), a second capacitor (18a, 28a) disposed between a first terminal of the inductive cell and ground, and a third capacitor (18b, 28b) disposed between a second terminal of the inductive cell and ground.

3. Electrical circuit according to claim 2, wherein the capacitance of the first capacitor (16) is less than or equal to 1 mF and greater than or equal to 10 nF.

4. Electrical circuit according to one of claims 2 or 3, in which the capacitance of the second capacitor (18a, 28a) and / or of the third capacitor (18b, 28b) is less than or equal to 1 mF and greater than or equal to 10 nF.

5. Electrical circuit according to any one of claims 2 to 4, in which the first capacitor (16, 26) is of type X and in which the second (18a, 28a) and the third (18b, 28b) capacitors are capacitors of type Y.

6. Electrical circuit according to one of the preceding claims, in which each of the inductances (17a, 17b, 24a, 24b) of the filtering cell (11, 21) has a value less than or equal to 1 mH and greater than or equal to 100 nH.

7. Electrical circuit according to any one of the preceding claims, wherein the two input terminals (13) are connected to a voltage network (5) via an AC / DC converter. 8 Electrical circuit according to one of claims 1 to 6, in which the two input terminals (13) are connected to an electrical energy storage unit (2).

9. Electrical circuit according to claim 8, in which the two switching arms define a DC / AC converter allowing impedance matching on the alternating input of this DC / AC converter independently of the impedance of the electrical energy storage unit (2), one of the first and second switching arms switching at the frequency of the energy exchanged without contact, and the other of the first and second arms switching at a frequency greater than or equal to 5 times or 10 times the frequency of the energy exchanged without contact.

10. Electrical power supply circuit of an electrical energy storage unit (2), comprising: - a first circuit according to any one of claims 1 to 7, called “primary circuit (4)”, - a second circuit according to any one of claims 1 to 6 or 8 or 9, called “secondary circuit (6)”, 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 of an inductor and a capacitor connected in series with the inductive cell (10) of the primary circuit (4), and - the voltage between the first (14) and second (15) midpoints of the secondary circuit (6) emulates the presence of an inductor and a capacitor connected in series with the inductive cell (20) of the secondary circuit (6), the inductive cell (10) of the primary circuit (4) and the inductive cell (20) of the secondary circuit (6) being configured so as to exchange electrical energy without contact by inductive coupling.

11. Device for supplying electricity to an electrical energy storage unit (2), comprising: - a charging terminal for a hybrid or electric vehicle, in which the primary circuit of the electrical circuit according to claim 10 is arranged or to which the primary circuit is connected, and - a component capable of being embedded in a hybrid or electric vehicle, in which the secondary circuit of the electrical circuit according to claim 10 is arranged.

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