Power supply circuit of an electrical energy storage unit

Abstract

Power supply circuit (1) of an electrical energy storage unit (2), this power supply circuit comprising: - a primary sub-circuit (4), suitable for connection to a voltage network (5), and - a secondary sub-circuit (6), suitable for connection to an electrical energy storage unit (2), the primary sub-circuit (4) and the secondary sub-circuit (6) being configured so as to exchange electrical energy without contact by inductive coupling, the secondary sub-circuit (6) comprising: - a secondary inductive cell (20) for the exchange of electrical energy with the primary sub-circuit (4) without contact by inductive coupling, - an inverter / rectifier (23) suitable for performing impedance matching of the impedance on the AC input of this inverter / rectifier (23), independently of the impedance of the electrical energy storage unit (2), this inverter / rectifier (23) comprising at least two switching arms (21),each switching arm (21) comprising two controllable electronic switches (12) arranged on either side of a midpoint (25), - a control unit (3), configured to control the controllable electronic switches (12) such that the portion of the secondary subcircuit across the secondary inductive cell behaves as a complex secondary impedance, this complex secondary impedance being the sum of a predefined number of complex secondary subimpedances, each complex secondary subimpedance comprising a real part and an imaginary part, and each complex secondary subimpedance being respectively associated with a harmonic of the frequency of the electrical energy exchanged without contact by inductive coupling. Abbreviated figure: Fig. 1,

Description

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

[0001] The present invention relates to a contactless 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 power a vehicle's electrical energy storage unit with a power output between 3 and 50 kW by contactless transmission via inductive coupling, whether the vehicle is stationary or moving. This contactless power supply is achieved by means of magnetically coupled, distant electrical sub-circuits tuned to the same resonant frequency. Each magnetically coupled sub-circuit employs an LC-type resonant cell.

[0004] The solution according to the application filed in France under No. 22 09978 on 30 / 09 / 2022, which is not part of the published prior 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 matching, allows the transmission of low-frequency electrical energy into an electrical energy storage unit, for example an electric vehicle battery.

[0005] Regulations for charging by inductive coupling impose a maximum level of magnetic and electric field.

[0006] The maximum limit of magnetic and electric field strength imposes a maximum power that can be transmitted by inductive coupling. In particular, knowing the waveform of the magnetic field (generally sinusoidal), which is a reflection of the current flowing from the primary inductive cell to the secondary inductive cell, it is possible to calculate the maximum theoretical power that can be transferred by inductive coupling.

[0007] There is a need to increase the maximum power that can be exchanged without contact by inductive coupling, without increasing the value of the magnetic and electric fields.

[0008] The invention aims to meet this need and achieves this by means of a

[0009] power supply circuit for an electrical energy storage unit, this power supply circuit comprising:

[0010] - a primary sub-circuit, suitable for connection to a voltage network, and

[0011] - a secondary sub-circuit, suitable for connection to an energy storage unit electric,

[0012] the primary sub-circuit and the secondary sub-circuit being configured so as to exchange electrical energy without contact by inductive coupling,

[0013] the secondary sub-circuit comprising:

[0014] - a secondary inductive cell for contactless exchange by inductive coupling of electrical energy with the primary sub-circuit,

[0015] - an inverter / rectifier capable of performing impedance matching of the impedance on the alternative input of this inverter / rectifier, independently of the impedance of the electrical energy storage unit, this inverter / rectifier comprising at least two switching arms, each switching arm comprising two controllable electronic switches arranged on either side of a midpoint,

[0016] - a control unit, configured to control the electronic switches controllable so that the part of the secondary subcircuit at the terminals of the secondary inductive cell behaves as a complex secondary impedance, this complex secondary impedance being the sum of a predefined number of complex secondary sub-impedances, each complex secondary sub-impedance comprising a real part and an imaginary part, and each complex secondary sub-impedance being respectively associated with a harmonic of the frequency of the electrical energy exchanged without contact by inductive coupling.

[0017] The use of such a complex secondary impedance can allow, when the current waveform passing from the primary inductive cell to the secondary inductive cell approaches a square shape instead of a sinusoidal shape, to best treat this current waveform without it being necessary to devote significant computing resources to it.

[0018] Advantageously, for the same amplitude and the same load impedance, switching from a sinusoidal current waveform to a square wave current waveform doubles the transmitted power. Using a square wave signal for inductively coupled energy transfer increases the maximum power that can be transmitted by inductive coupling without increasing the strength of the magnetic and electric fields. Indeed, the maximum power that can be transmitted for a given current amplitude is proportional to the RMS value of the current signal. However, for a signal of a given amplitude, the RMS value of a square wave signal is greater than the RMS value of a sinusoidal wave signal.

[0019] As will be seen later, the voltage applied to the primary inductive cell is decomposed into several of its harmonics, which leads to a current shape approaching a square wave.

[0020] Typically, a square wave can be decomposed into N odd-order harmonics, i.e., signals with frequencies F, 3*F, 5*F, 7*F, [...], 2i-1*F, where F is the fundamental frequency of the signal. The number N of harmonics is, for example, less than or equal to 5, corresponding to the first 3 odd harmonics, namely the fundamental frequency, the 3rd harmonic, and the 5th harmonic.

[0021] To achieve a result that tends towards a square shape, a finite number of harmonics, adapted in phase and amplitude, can be used to get closer to this square shape of the current.

[0022] The complex secondary impedance may comprise at least two complex secondary sub-impedances, respectively associated with the fundamental and the third harmonic of the frequency of the electrical energy exchanged without contact by inductive coupling. Each complex secondary sub-impedance may exhibit a resonant frequency for the frequency value corresponding to the harmonic in question.

[0023] The complex secondary impedance includes, for example:

[0024] - a complex secondary underimpedance associated with the fundamental frequency electrical energy exchanged without contact via inductive coupling,

[0025] - a complex secondary subimpedance associated with the 3rd harmonic of the frequency of electrical energy exchanged without contact by inductive coupling,

[0026] - a complex secondary subimpedance associated with the 5th harmonic of the frequency of electrical energy exchanged without contact by inductive coupling, and

[0027] - a complex secondary subimpedance associated with the 7th harmonic of the frequency of electrical energy exchanged without contact by inductive coupling.

[0028] Each of these complex secondary sub-impedances resonates, for example, at the harmonic to which it is associated with the voltage applied to the terminals of the primary inductive cell.

[0029] The inverter / rectifier can comprise exactly two switching arms, and the secondary inductive cell is mounted between the two midpoints of this inverter / rectifier.

[0030] In all the above, the complex secondary impedance can be determined using equation [Math.1] Zi, = ^=77777 * (¾ + ) 1+ <t>. J /

[0031] where: e2k is the damping coefficient for the kth harmonic, cok is the angular frequency at the resonance frequency for the kth harmonic, N is the maximum rank of the frequency harmonic considered, C2k is a capacitor compensating for the leakage inductance in the secondary sub-circuit for the harmonic of rank k, R2k is a load resistance for the harmonic of rank k, A2 is a constant, and s is the Laplace variable.

[0032] Each complex secondary subimpedance then acts as a second-order bandpass filter, which cancels the impedance value (R2k+1 / C2k.s) across the entire frequency band, except for the resonance frequency of the kth harmonic. Thus, each complex secondary subimpedance has no influence on harmonics of any order other than the one to which it is associated, a result that cannot be achieved with an analog solution. This effect can be obtained using a simple implementation method.

[0033] In all the foregoing, the secondary inductive cell can be constituted by an inductor, the presence of a capacitor mounted in series with the secondary inductive cell being emulated in each secondary complex subimpedance using the quantity C2k

[0034] In all the foregoing, when the inverter / rectifier comprises exactly two switching arms, one of these two arms can be controlled to switch at the fundamental frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle of 50%, and the other of these two arms can be controlled to switch at a frequency higher than that of said electrical energy and with a duty cycle modulated according to the alternating current flowing in the secondary inductive cell and the voltage at the AC input of this inverter / rectifier. The impedance at the AC input of the inverter / rectifier of the secondary subcircuit is represented by the ratio V / I where V is the voltage across the secondary inductive cell and I is the current flowing through it.Impedance matching thus makes it possible to impose on the AC input of the inverter / rectifier of the secondary sub-circuit an impedance independent of that of the electrical energy storage unit, which promotes contactless exchange of low-frequency electrical energy via inductive coupling.

[0035] The secondary sub-circuit may include a current sensor mounted in series with the secondary inductive cell. When the secondary sub-circuit includes two parallel switching arms, the current sensor and the secondary inductive cell are, for example, mounted in series between the two midpoints of the switching arms.

[0036] In all the foregoing, the primary subcircuit may include:

[0037] - a primary inductive cell for contactless exchange by inductive coupling of electrical energy with the secondary inductive cell, and

[0038] - an inverter / rectifier comprising at least two switching arms, each switching arm comprising two controllable electronic switches arranged on either side of a midpoint,

[0039] the control unit being configured to control the controllable electronic switches of the inverter / rectifier of the primary sub-circuit so as to apply to the terminals of the primary inductive cell a voltage at each harmonic rank of the predefined number of harmonics.

[0040] As already indicated, the voltage applied to the primary inductive cell is, for example, decomposed into several of its harmonics, which makes it possible to obtain a current shape approaching a square wave, for example:

[0041] - into a sinusoidal signal whose frequency is equal to the fundamental of the frequency electrical energy exchanged without contact via inductive coupling,

[0042] - into a sinusoidal signal whose frequency is equal to the 3rd harmonic of the frequency of electrical energy exchanged without contact by inductive coupling,

[0043] - into a sinusoidal signal whose frequency is equal to the 5th harmonic of the frequency of the electrical energy exchanged without contact by inductive coupling, and where applicable

[0044] - into a sinusoidal signal whose frequency is equal to the 7th harmonic of the frequency of electrical energy exchanged without contact by inductive coupling.

[0045] The control unit command to apply a voltage to the terminals of the primary inductive cell at each harmonic rank of the predefined number of harmonics can ensure that the difference between the amplitude of this voltage for harmonic rank k is between + and - 10% of the value ak for this amplitude given by the following formula:

[0046] [Math.2]

[0047] where U denotes the peak-to-peak amplitude of the voltage applied across the terminals of the primary inductive cell and k denotes the rank of the harmonic considered.

[0048] The control unit command to apply a voltage to the terminals of the primary inductive cell at each harmonic rank of the predefined number of harmonics can allow the phase shift between all the harmonics of this voltage, considered two by two, to be less than or equal to ±20°, or even zero.

[0049] The control unit can further be configured to control the controllable electronic switches of the inverter / rectifier so that the voltage applied to the terminals of the primary inductive cell is, for each harmonic rank, constituted by the series connection of a voltage source and a complex primary subimpedance.

[0050] Each complex primary subimpedance can be devoid of a real part. The absence of a real part for these complex primary subimpedances makes it possible to avoid energy consumption in the primary subcircuit, but to conserve energy. for transmission to the secondary sub-circuit.

[0051] Each complex primary subimpedance can be determined using the expression: [Math.3]

[0052] where: Elk is the damping coefficient for the kth harmonic, cok is the angular frequency at the resonance frequency for the kth harmonic, C[k is a capacitor whose capacitance value is chosen to form a resonant cell for the kth harmonic, Al is a constant, and s is the Laplace variable. Thanks to C[k, each complex primary subimpedance allows us to emulate, for the kth harmonic, a capacitor in series with the inductance in the primary inductive cell.

[0053] The primary inductive cell can be constituted by an inductance.

[0054] Typically, the electrical energy storage unit can 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.

[0055] Typically, the contactless exchange by inductive coupling of electrical energy takes place at a fundamental frequency below 5 kHz, for example below 3kHz, or even below 2kHz or 1kHz, in particular still substantially equal to 400 Hz or 50 Hz.

[0056] The electrical network supplies, 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. Alternatively, the electrical network may supply a direct current voltage.

[0057] The electrical network is, for example, a regional or national electrical network. 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.

[0058] The electrical circuit may include a control unit configured to control the switching arms of the primary and / or secondary sub-circuit. According to the present invention, when an arm switches, each of its two controllable electronic switches is opened and closed in a complementary manner with the same switching frequency.

[0059] In all the above, the control unit can be configured to control the different switching arms of the primary and secondary sub-circuits so as to selectively perform:

[0060] - a charge of the electrical energy storage unit from the voltage network, Or

[0061] - a load from the voltage network from the electrical energy storage unit.

[0062] Thus, depending on the need, the exchange of electrical energy can take place in one direction or the other.

[0063] In all the foregoing, 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.

[0064] In all the above, the control unit may be a digital processing circuit, for example an ASIC (Application-specific integrated circuit) or a microcontroller.

[0065] In all the above, the complex secondary impedance and / or each complex primary sub-impedance can be determined by software.

[0066] The control unit may alternatively include a primary sub-circuit control module and a secondary sub-circuit control module.

[0067] Alternatively, each sub-circuit has its own control unit, the latter being a digital processing circuit such as a microcontroller.

[0068] The invention also relates, according to another aspect, to a component for the power supply of an electrical energy storage unit, comprising the electrical circuit as defined above, the component defining in particular a structure rigidly coupled to each other supporting the primary and secondary sub-circuits. Such a component is commonly called an "on-board charger." This component is suitable for installation in a hybrid or electric vehicle.

[0069] The invention also relates, according to another aspect, to a device for supplying power to an electrical energy storage unit, comprising:

[0070] - a charging station for hybrid or electric vehicles, in which is arranged the primary sub-circuit of the electrical circuit as defined above, or to which this primary sub-circuit is electrically connected, and

[0071] - a component suitable for being installed in a hybrid or electric vehicle, in which is arranged the secondary sub-circuit of the electrical circuit as defined above.

[0072] This terminal then receives electrical energy from an electrical network via a cable, which can be a single-phase or three-phase cable. In this case, the primary and secondary circuits are not integrated into the same physical component.

[0073] The invention will be better understood upon reading the following description of a non-limiting example of its implementation and upon examination of the accompanying drawing in which:

[0074] [Fig. 1] schematically represents an electrical circuit according to an example of implementation of the invention.

[0075] Figure 1 shows a power supply circuit 1 for 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 power a propulsion system of an electric or hybrid vehicle.

[0076] This power supply circuit 1 comprises:

[0077] - a control unit 3,

[0078] - a primary sub-circuit 4, suitable for connection to a voltage network 5, and

[0079] - a secondary sub-circuit 6, comprising the electrical energy storage unit 2.

[0080] The power supply circuit 1 implements a contactless exchange of electrical energy by inductive coupling between the primary sub-circuit 4 and the secondary sub-circuit 6, for the charging of the electrical energy storage unit 2.

[0081] The control unit 3 is for example a microcontroller or any digital processing unit.

[0082] In the example considered, the primary sub-circuit 4 comprises:

[0083] - a connector 9 suitable for being connected to the electrical network,

[0084] - an inverter / rectifier 21 comprising here two switching arms 7, mounted in parallel, and whose operation will be described below, and

[0085] - a primary inductive cell whose operation will be described below.

[0086] The electrical network 5 is represented here in the form of a voltage network The network may be continuous, but alternatively, it may be an alternating voltage network supplying, for example, a nominal RMS voltage of 230V with a frequency of 50 Hz or 60 Hz. Such an alternating voltage network can be single-phase or three-phase. Other voltages are possible, for example, a single-phase RMS voltage of 120V and a frequency of 60 Hz, a two-phase RMS voltage of 208V and a frequency of 60 Hz, or a three-phase voltage of 240V and a frequency of 60 Hz; this list is not exhaustive. If the network supplies alternating voltage, another inverter / rectifier (not shown) is provided between the network and the inverter / rectifier 21. This other inverter / rectifier provides, for example, a power factor correction function.

[0087] As can be seen in [Fig.1], a capacitor 15 can be arranged in parallel with the two switching arms 7. The latter has, for example, a capacitance between IpF and ImF, for example of lOpF.

[0088] Each arm 7 of the primary subcircuit 4 here comprises two controllable electronic switches 12, such as MOS, IGBT or bipolar transistors, or thyristors, arranged on either side of a midpoint 8. The two switches 12 of the same switching arm 7 are here controlled using the same ratio cyclic, one in opposition to the other with a dead time by the control unit 3, although only some functional control links are represented on the [Fig.1].

[0089] The first arm 7 thus comprises two controllable electronic switches 12 and a first midpoint 8 to which a terminal of the primary inductive cell 10 is connected, and these two controllable electronic switches 12 are controlled according to a duty cycle ab

[0090] The second arm 7 thus comprises two controllable electronic switches 12 and a second midpoint 8 to which the other terminal of the primary inductive cell 10 is connected and these two controllable electronic switches 12 are controlled according to a duty cycle a2.

[0091] In the example considered, no physical component is interposed between the two midpoints 8 of the inverter / rectifier 21 and the primary inductive cell 10.

[0092] The primary inductive cell 10 is here constituted by an inductor. The latter has, for example, a value between 10H and 10MH, and the capacitor has a capacitance between 10 nF and 1 mF. The inductor is, for example, made by winding a copper wire, other than Litz wire. No capacitor as a physical component is present here to form the primary inductive cell 10. A common-mode noise and / or differential-mode noise filtering cell, as disclosed in the application filed by the present Applicant in France under number 23 07088 on 04 / 07 / 2023, may be provided in the primary sub-circuit 4.

[0093] In the example considered, the control unit 3 controls the switching arms 7 so that the voltage applied across the terminals of the primary inductive cell 10 is decomposed into several of its harmonics, resulting in a current waveform approaching a square wave. Here, and without limitation, the voltage is decomposed into the voltage at the fundamental frequency, the 3rd harmonic, and the 5th harmonic.

[0094] In the example considered, the voltage applied across the terminals of the primary inductive cell 10 corresponds to the superposition:

[0095] - of a sinusoidal signal at frequency f0,

[0096] - of a sinusoidal signal at frequency 3*f0, and

[0097] - of a sinusoidal signal at the frequency 5*f0.

[0098] The control of the switching arms 7 by the control unit 3 is here again such as that for each harmonic of rank 1, 3 or 5 the difference between the voltage amplitude of the aforementioned sinusoidal signal is between + and - 10% of the value ak for this amplitude given by the following formula:

[0099] [Math.4]

[0100] where U denotes the peak-to-peak amplitude of the voltage applied across the terminals of the primary inductive cell and k denotes the rank of the harmonic considered.

[0101] The control of the switching arms 7 by the control unit 3 is here also such that the phase shift between all the harmonics of this voltage, considered two by two, is less than or equal to ±20°, or even zero.

[0102] In the example considered, the control of the switching arms 7 by the control unit 3 is also such that the voltage applied to the terminals of the primary inductive cell 10 is, for each harmonic rank, constituted by the series connection of a voltage source and a complex primary sub-impedance.

[0103] Each complex primary subimpedance has, for example, the following expression:

[0104] [Math.5] (' ^x^xsxAi \ ..... x (7¾)

[0105] where: Elk is the damping coefficient for the kth harmonic, cok is the angular frequency at the resonance frequency for the kth harmonic, Cik is a capacitor whose capacitance value is chosen to form a resonant cell for the kth harmonic, Al is a constant, and s is the Laplace variable.

[0106] We will now describe an example of a secondary subcircuit 6 with reference to [Fig.1]. This secondary subcircuit 6 comprises a secondary inductive cell 20 for the exchange of energy without contact with the primary inductive cell 10, and an inverter / rectifier 23, capable of performing an adaptation of the equivalent impedance on its AC input (i.e. 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.

[0107] The inverter / rectifier 23 in the described example comprises two switching arms 24 arranged in parallel, each arm comprising two controllable electronic switches 12 arranged on either side of a midpoint 25.

[0108] The two switches 12 of the same switching arm 24 are here controlled using the same duty cycle, one in opposition to the other with a dead time by the control unit 3, although only some functional control links are shown in [Fig.1].

[0109] The first arm 24 thus comprises two controllable electronic switches 12 and a first midpoint 25 to which a terminal of the secondary inductive cell 20 is connected and these two controllable electronic switches 12 are controlled according to a duty cycle a3.

[0110] The second arm 24 thus comprises two controllable electronic switches 12 and a second midpoint 25 to which the other terminal of the secondary inductive cell 20 is connected, and these two controllable electronic switches 12 are ordered according to a cyclic ratio a4.

[0111] The secondary inductive cell 20 is here formed by an inductance only. The inductance here has a value between ImH and lOOmH and is, for example, made by winding a copper wire, other than Litz wire.

[0112] Furthermore, the control unit 3 acts in the described example on the control of the inverter / rectifier 23 so as to vary the equivalent impedance RRef across the terminals of the AC input, defined between the two midpoints 25 of the switching arms 24, independently of the impedance on the DC output of this inverter / rectifier 23.

[0113] The equivalent impedance RRef is represented by the ratio V / I where V is the voltage between the two midpoints 25, and I is the intensity of the current flowing in the secondary inductive cell 20.

[0114] RRef, for example, has a value between 0.1 'Q and 20 'Q, in particular between 5 'Q and 15 'Q. For a given charging configuration, this configuration being determined in particular by at least one of the following: the position of the secondary sub-circuit 6 relative to the primary sub-circuit 4 and / or the power level to be transmitted and / or the voltage across the terminals of the electrical energy storage unit 2, RRef may have a fixed value, and this value is, for example, within the aforementioned range. From one charging configuration to another, for example in the case of a greater distance between the primary sub-circuit 4 and the secondary sub-circuit 6 and / or to take into account the aging of the system, the value of RRef may be modified, remaining in particular within the aforementioned range.

[0115] The inverter / rectifier 23 of [Fig. 1] is, for example, controlled as follows by the control unit 3, to perform impedance matching on the AC input of the inverter / rectifier 23:

[0116] - one of the two switching arms 24 switches at the fundamental frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle a3 of 50%, and

[0117] - the other of the two switching arms 24 switches at a frequency higher than that of the electrical energy exchanged without contact, for example at least 5 times or 10 times this fundamental frequency of the electrical energy exchanged without contact, and with a duty cycle a4 modulated according to the alternating current in the secondary inductive cell 20 and according to the voltage across the AC input of the inverter / rectifier 23. One of the controllable switches 12 of the switching arm 24 which switches at a frequency higher than that of the electrical energy exchanged without contact is for example driven according to a duty cycle a4 while the other controllable switch of this arm 24 is driven according to a duty cycle 1-a4, and a4 is for example determined according to the equation below:

[0118] a4=(Rref xlll ) / Vbatt

[0119] where Vbatt denotes the voltage across the terminals of the electrical energy storage unit 2.

[0120] Still in the example considered, the control by the duty cycle a4 allows the part of the secondary sub-circuit 6 at the terminals of the secondary inductive cell 20 to behave as a complex secondary impedance Z2eq.

[0121] In all the above, the complex secondary impedance can be determined using the equation [Math.6]

[0122] where: e2k is the damping coefficient for the kth harmonic, cok is the angular frequency at the resonance frequency for the kth harmonic, N is the maximum rank of the frequency harmonic under consideration, C2k is a capacitor compensating the leakage inductance in the secondary sub-circuit for the kth harmonic, R2k is a load resistance for the kth harmonic, A2 is a constant, and s is the Laplace variable.

[0123] Each complex secondary subimpedance is then a 2nd order bandpass filter which allows the value of the impedance (R2k+1 / C2k.s) to be canceled over the entire frequency band, except for the resonance frequency for the kth harmonic.

[0124] The invention is not limited to the example just described.

[0125] Thus, in other examples, the inverter / rectifier 7 of the primary sub-circuit 4 is always controlled so that the voltage applied across the terminals of the primary inductive cell 10 is decomposed into several of its harmonics, but there is no complex sub-impedance on the side of the primary sub-circuit 4. Thus, the voltage applied across the terminals of the primary inductive cell 10 is no longer, for each harmonic rank, constituted by the series connection of a voltage source and a primary complex sub-impedance.

[0126] Moreover, although only one control unit 3 is shown, other embodiments are possible, for example the possibility that one control unit is dedicated to the control of the primary sub-circuit 4 and that another control unit is dedicated to the control of the secondary sub-circuit 6.< / t>

Claims

Claims

1. Electrical power supply circuit (1) for an electrical energy storage unit (2), this electrical power supply circuit comprising: - a primary sub-circuit (4), capable of being connected to a voltage network (5), and - a secondary sub-circuit (6), capable of being connected to an electrical energy storage unit (2), the primary sub-circuit (4) and the secondary sub-circuit (6) being configured so as to exchange electrical energy without contact by inductive coupling, the secondary sub-circuit (6) comprising: - a secondary inductive cell (20) for the contactless exchange by inductive coupling of electrical energy with the primary sub-circuit (4), - an inverter / rectifier (23) capable of performing an impedance adaptation of the impedance on the alternating input of this inverter / rectifier (23), independently of the impedance of the electrical energy storage unit (2), this inverter / rectifier (23) comprising at less two switching arms (21),each switching arm (21) comprising two controllable electronic switches (12) arranged on either side of a midpoint (25), - a control unit (3), configured to control the controllable electronic switches (12) so that the part of the secondary sub-circuit at the terminals of the secondary inductive cell behaves like a complex secondary impedance, this complex secondary impedance being the sum of a predefined number of secondary complex sub-impedances, each complex secondary sub-impedance comprising a real part and an imaginary part, and each complex secondary sub-impedance being respectively associated with a harmonic of the frequency of the electrical energy exchanged without contact by inductive coupling.,

2. Circuit according to claim 1, the complex secondary impedance comprising at least two complex secondary sub-impedances, being respectively associated with the fundamental and the harmonic of rank 3 of the frequency of the electrical energy exchanged without contact by inductive coupling.

3. A circuit according to claim 1 or 2, the inverter / rectifier (23) comprising exactly two switching arms (24), the cell secondary inductive (20) being mounted between the two midpoints (25) of this inverter / rectifier (23).

4. A circuit according to claim 1 or 2, the complex secondary impedance being determined using the equation fï / V / ---|} X ) where: e2k is the damping coefficient for the harmonic of order k, cok is the pulsation at the resonant frequency for the harmonic of order k, N is the maximum order of the harmonic of frequency considered, C2k is a capacitor for compensating the leakage inductance in the secondary sub-circuit for the harmonic of order k, R2k is a load resistance for the harmonic of order k, A2 is a constant, and s is the Laplace variable.

5. Circuit according to any one of the preceding claims, the secondary inductive cell (20) being constituted by an inductance.

6. A circuit according to any one of the preceding claims, the inverter / rectifier (23) comprising exactly two switching arms, one of these two arms being controlled to switch at the fundamental frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle of 50%, and the other of these two arms being controlled to switch at a frequency higher than that of said electrical energy and with a duty cycle modulated according to the alternating current flowing in the secondary inductive cell (20) and the voltage on the alternating input of this inverter / rectifier (23).

7. Circuit according to any one of the preceding claims, the primary sub-circuit (4) comprising: - a primary inductive cell for the contactless exchange by inductive coupling of electrical energy with the secondary inductive cell, and - an inverter / rectifier (21) comprising at least two switching arms (7), each switching arm comprising two controllable electronic switches (12) arranged on either side of a midpoint (8), the control unit (3) being configured to control the controllable electronic switches (12) of the inverter / rectifier (21) of the primary sub-circuit so as to apply to the terminals of the primary inductive cell (10) a voltage at each harmonic order of the predefined number of harmonics.

8. Circuit according to claim 7, the control unit being further configured to control the controllable electronic switches of the inverter / rectifier (21) so that the voltage applied to the terminals of the primary inductive cell (10) is, for each harmonic order, constituted by the series connection of a voltage source and a complex primary sub-impedance.

9. A circuit according to claim 8, each complex primary sub-impedance being devoid of a real part.

10. A circuit according to claim 8 and claim 4, each complex primary sub-impedance being determined using the expression — 1 — ----------7 IX 1 —■ J Elk is the damping coefficient for the harmonic of order k, cok is the pulsation at the resonant frequency for the harmonic of order k, N is the maximum order of the harmonic of frequency considered, Cik is a capacitor whose capacitance value is chosen to form a resonant cell for the harmonic of order k, Al is a constant, and s is the Laplace variable.

11. Component for the electrical supply of an electrical energy storage unit (2), comprising the electrical circuit (1) according to any one of the preceding claims, the component defining in particular a structure supporting in a rigidly coupled manner the primary sub-circuit (4) and the secondary sub-circuit (6).

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

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