Electrical power supply circuit for a vehicle electrical energy storage unit

Abstract

The invention relates to a secondary sub-circuit (6) for supplying electrical power to an electrical energy storage unit (2), this sub-circuit (6) being able to contactlessly exchange, via inductive coupling, electrical energy with a primary sub-circuit (4) able to be connected to a voltage network (5), and this sub-circuit (6) also being able to be connected to an electrical energy storage unit (2), the secondary sub-circuit (6) comprising: - a secondary inductive cell (20) for contactlessly exchanging, via inductive coupling, electrical energy with the primary sub-circuit (4), - an inverter / rectifier (23) able to carry out 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 (24), namely: - a first switching arm switching at the frequency of the electrical energy induced in the secondary inductive cell (20), and - a second switching arm (24) switching at a frequency higher than that of the electrical energy and with a duty cycle modulated in accordance with the AC current flowing in the secondary inductive cell (20) and the voltage on the AC input of this inverter / rectifier (23), the second switching arm comprising two switching cells (12) arranged on either side of a midpoint (25) of this second switching arm, at least one of these switching cells (12) comprising at least two controllable electronic switches (29) arranged in parallel.

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 electrical energy storage unit by contactless exchange using inductive coupling at a power of between 3 and 50 kW, when the vehicle is stationary or when it is moving. This contactless exchange 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. 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. It is desirable to increase the efficiency of such a contactless exchange power supply.

[0005] The invention aims to meet this need and achieves this, according to one of its aspects, using a secondary sub-circuit for the electrical power supply of an electrical energy storage unit, this secondary sub-circuit being capable of exchanging electrical energy without contact by inductive coupling with a primary sub-circuit capable of being connected to a voltage network, and this secondary sub-circuit also being capable of being connected to an electrical energy storage unit, the secondary sub-circuit comprising:

[0006] - a secondary inductive cell for contactless exchange by inductive coupling of electrical energy with a primary inductive cell of the primary sub-circuit,

[0007] - an inverter / rectifier capable of performing an impedance adaptation of the impedance on the alternating input of this inverter / rectifier, independently of the impedance of the electrical energy storage unit, this inverter / rectifier comprising at least two switching arms, namely:

[0008] - a first switching arm switching at the frequency of the electrical energy induced in the secondary inductive cell and,

[0009] - a second switching arm switching 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 on the alternating input of this inverter / rectifier, the second switching arm comprising two switching cells arranged on either side of a midpoint of this second switching arm, at least one of these switching cells comprising at least two controllable electronic switches arranged in parallel.

[0010] According to the invention, the impedance matching technique can thus be used to reduce, for a given current value in the secondary inductive cell, the value of the current flowing in the primary inductive cell, hence an increase in the efficiency of the exchange of electrical energy. This technique can then be used, including when this impedance matching requires the use of high switching frequencies in the second switching arm. In the case where the contactless exchange by inductive coupling of electrical energy between the primary inductive cell and the secondary inductive cell takes place at approximately 85 kHz, this frequency in the second switching arm can rise to more than 400 kHz, or even more than 800 kHz.The use in the second switching arm of a switching cell with at least two controllable electronic switches arranged in parallel makes it possible to distribute the current conduction and switching stress between the various controllable electronic switches in parallel in the switching cell. In practice, this results in a reduction in the switching frequency per controllable electronic switch. Less complex and / or less expensive controllable electronic switches are thus used in the switching cell.

[0011] The secondary sub-circuit may comprise a control unit of the switching cell, this control unit comprising: a piloting unit, and a selection stage arranged downstream of the piloting unit, this selection stage allowing the differentiated control of the controllable switches of the switching cell. The control current is thus directed using the selection stage to the controllable electronic switch of the switching cell concerned by the next conduction phase. The controllable electronic switches of the switching cell can be controlled in such a way that at any time there is at most one controllable electronic switch of the switching cell which is in the on state. There is thus no conduction overlap between different controllable electronic switches of the switching cell.Alternatively, some of the controllable electronic switches of the switching cell are controlled to the on state synchronously.

[0012] The selection stage may comprise two selection blocks, each block applying to a respective switch of the switching cell a control signal between the control electrode of said switch and the same potential of the second switching arm. Each selection block is for example produced using two transistors according to an inexpensive solution. These are for example so-called signal transistors. For the purposes of the present application, a field effect transistor may be qualified as a signal transistor when its drain-source voltage is less than 100V and when its drain current is less than 10A.

[0013] In the case where the switching cell is located between the midpoint of the second switching arm and the continuous positive potential of the inverter / rectifier, each block applies for example to a respective switch of the switching cell a control signal between the control electrode of said switch and the midpoint of the second switching arm.

[0014] In the case where the switching cell is located between the midpoint of the second switching arm and the lowest DC potential (which may be ground or a negative DC potential) of the inverter / rectifier, each block applies for example to a respective switch of the switching cell a control signal between the control electrode of said switch and this lowest DC potential.

[0015] The transistors of the selection block are for example mounted in such a way that the opening of the controllable electronic switch controlled by this selection block is done via a discharge current circulating in the intrinsic diode of one of the transistors of this selection block.

[0016] Each selection block can receive a drive signal from the drive unit and a counter signal from a counter in the control unit.

[0017] When the selection block is implemented using two field effect transistors, the control signal is for example received by the drain of a first of these two transistors while the counter signal is received by the gate of a second of these two transistors. In this case, the drain of the second transistor can be directly connected to the gate of the first transistor.

[0018] The counter is, for example, a ring counter. The control signal is, for example, the same as that sent by the control unit to the selection stage. The control signal is, for example, a square wave signal. Each reception by the counter of a rising or falling edge in the control signal causes, for example, the counter to designate the next controllable electronic switch for conduction in the switching cell and to send the corresponding command to the selection stage. In all of the above, the switching cell may comprise between 2 and 5 controllable electronic switches arranged in parallel, for example 4 controllable electronic switches arranged in parallel. Each controllable electronic switch is, for example, a MOSFET, IGBT or bipolar transistor, or a thyristor. The MOSFET transistor is, for example, made from SiC.Alternatively, it can be a GaN-based high electron mobility transistor (HEMT).

[0019] Each switching cell of the second switching arm comprises, for example, several controllable electronic switches arranged in parallel, in particular between 2 and 5 controllable electronic switches arranged in parallel. Such a solution is compatible with impedance matching with a frequency of the electrical energy exchanged without contact by inductive coupling of 85 kHz, and it is reversible.

[0020] According to what has just been mentioned, two control units can be provided, each being dedicated to a respective switching cell of the second switching arm. Alternatively, a single control unit can be provided for the second switching arm, the latter comprising for example a single control unit and a single counter, and two selection stages, each selection stage being dedicated to a switching cell and cooperating with the counter.

[0021] According to a first example of implementation of the invention, the first switching arm comprises two switching cells each located on a respective side of the midpoint of this first switching arm and each of these cells comprises a single electronic switch, in particular controllable. Thus, a single switch is interposed between the midpoint of this first switching arm and the positive DC potential of the inverter / rectifier, and a single switch is interposed between this midpoint and the lowest DC potential of the inverter / rectifier.

[0022] According to a second example of implementation of the invention, the first switching arm may comprise, between its midpoint and at least one of the DC potentials of the inverter / rectifier, in particular between its midpoint and each DC potential of the inverter / rectifier, a switching cell comprising several electronic switches, in particular controllable ones, mounted in parallel. When these controllable electronic switches are mounted in parallel, they receive the same command, and not a differentiated command as applied to the controllable electronic switches of a switching cell of the second switching arm. These controllable electronic switches of the first arm which are mounted in parallel are then simultaneously in the on state, respectively blocking state.

[0023] In all of the above, the first switching arm can switch at the frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle of 50%, and the second switching arm can switch at a frequency equal to or greater than 5 times or 10 times the frequency of the electrical energy exchanged without contact by inductive coupling. The impedance on the AC input of the inverter / rectifier of the secondary sub-circuit is represented by the ratio V / I where V is the voltage across the terminals of the secondary inductive cell and I the intensity of 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.

[0024] In all of the above, the secondary inductive cell can be constituted by the series association of a capacitor and an inductance.

[0025] Alternatively, in all of the above, the secondary inductive cell may be constituted by an inductor, the switching arms of the inverter / rectifier being controlled so that the voltage across the AC input of this inverter / rectifier emulates the presence of a capacitor connected in series with the secondary inductive cell. Such a control making it possible to obtain this emulation is described in the international application filed on May 31, 2024 by the Applicant under number PCT / EP2024 / 065125. The content of this application is incorporated by reference into the present application with regard to the control of the duty cycles of the switching arms of the inverter / rectifier.

[0026] In all of the above, the secondary inductive cell may have a resonance frequency between 79 kHz and 90 kHz, being in particular equal to 85 kHz.

[0027] In all of the above, the secondary sub-circuit may include the electrical energy storage unit. The latter 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.

[0028] The electrical energy storage unit is, for example, directly or indirectly connected to the switching arms of the inverter / rectifier. The electrical energy storage unit is, for example, connected in parallel with the switching arms of the inverter / rectifier. Alternatively, the electrical energy storage unit is not directly connected in parallel with the switching arms of the inverter / rectifier. A mesh comprising one or more impedances in series with the electrical energy storage unit is, for example, connected in parallel with the switching arms of the inverter / rectifier.

[0029] The invention also relates, according to another of its aspects, to an electrical power supply circuit for an electrical energy storage unit, this electrical power supply circuit comprising: - a primary sub-circuit, capable of being connected to a voltage network, and

[0030] - the secondary sub-circuit as defined above, the primary sub-circuit comprising:

[0031] - a primary inductive cell for contactless exchange by inductive coupling of electrical energy with the secondary inductive cell, and

[0032] - an inverter / rectifier comprising at least two switching arms, each switching arm comprising two controllable electronic switches arranged on either side of a midpoint.

[0033] The secondary inductive cell and the primary inductive cell are advantageously chosen so that they have the same resonance frequency, in particular a resonance frequency between 79 kHz and 90 kHz, for example being of the order of 85 kHz.

[0034] In all of the above, the primary inductive cell may be constituted by the series association of a capacitor and an inductor. Alternatively, and similarly to what has been mentioned in relation to the secondary inductive cell, the primary inductive cell may be constituted by an inductor, the switching arms of the inverter / rectifier of the primary sub-circuit being controlled in such a way that the voltage across the AC input of this inverter / rectifier emulates the presence of a capacitor connected in series with the primary inductive cell.

[0035] If necessary, the primary sub-circuit may include another inverter / rectifier mounted upstream of the inverter / rectifier at the midpoints of which the primary inductive cell is mounted, and this other inverter / rectifier makes it possible to rectify the AC voltage received from the network when the load is made from an AC voltage network. This other inverter / rectifier can then perform a power factor correction function. Such a correction allows, in a known manner, that the current drawn from the network is as close as possible to a perfect sine wave at the network pulse. This reduces the reactive current and the sub-harmonics which increase energy losses in conduction.

[0036] The primary inductive cell may be integrated into a charging mat placed in or on the ground, as described in the application filed by this Applicant on 09 / 11 / 2023 under number 2309545.

[0037] In all of the above, the electricity grid provides, for example, a nominal effective voltage of 230V with a frequency of 50 Hz or 60 Hz. The electricity grid is, for example, single-phase. The electricity grid is, for example, a regional or national electricity grid. 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.

[0038] Alternatively, the electrical network can provide direct voltage.

[0039] The electrical circuit may comprise a control unit configured to control the switching arms of the primary sub-circuit and / or the secondary sub-circuit. For the purposes of 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. The or each aforementioned control unit then belongs to the control unit.

[0040] In all of the above, the control unit can be configured to control the different switching arms so as to selectively achieve:

[0041] - a charge of the electrical energy storage unit from the voltage network, or

[0042] - a load of the voltage network from the electrical energy storage unit.

[0043] Thus, depending on the need, the exchange of electrical energy can take place in one direction or the other.

[0044] In all of the above, each switching arm comprises controllable electronic switches, in particular exclusively electronic switches which are controllable, and each controllable electronic switch is for example a transistor, for example bipolar, MOSEET or IGBT, or a thyristor or a switch of the HEMT type already mentioned above. Each controllable electronic switch is for example bidirectional.

[0045] In all of the above, the control unit can be a digital processing circuit, for example an ASIC (Application-specific integrated circuit) or a microcontroller. This control unit can control all the switching arms of the electrical circuit, whether they belong to the primary sub-circuit or the secondary sub-circuit.

[0046] The control unit may alternatively comprise a primary sub-circuit control module and a secondary sub-circuit control module.

[0047] Alternatively, each sub-circuit has its own control unit, which may be a digital processing circuit such as a microcontroller.

[0048] 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 sub-circuit and the secondary sub-circuit. Such a component is commonly called an “on-board charger”. This component is capable of being embedded in a hybrid or electric vehicle.

[0049] The invention also relates, according to another of its aspects, to a device for supplying electricity to an electrical energy storage unit, comprising:

[0050] - a charging terminal for a hybrid or electric vehicle, in which the primary sub-circuit of the electrical circuit as defined above is arranged or to which this primary sub-circuit is electrically connected, and

[0051] - a component capable of being fitted into a hybrid or electric vehicle, in which the secondary sub-circuit of the electrical circuit as defined above is arranged.

[0052] 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.

[0053] In all of the above, the inductive cell can be configured to exchange with the other inductive cell a power whose value is between 3 kW and 50 kW.

[0054] The invention may be better understood by reading the following description of non-limiting examples of its implementation and by examining the attached drawing in which:

[0055] [Fig.l] schematically represents an electrical power supply circuit according to a first example of implementation of the invention, and

[0056] [Fig.2] shows in detail the secondary sub-circuit of the circuit of Figure 1.

[0057] 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.

[0058] This power supply circuit 1 includes:

[0059] - a control unit 3,

[0060] - a primary sub-circuit 4, capable of being connected to a voltage network 5, and

[0061] - a secondary sub-circuit 6, comprising the electrical energy storage unit 2.

[0062] 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 charging the electrical energy storage unit 2.

[0063] The control unit 3 is for example a microcontroller or any digital processing unit.

[0064] In the example considered, the primary sub-circuit 4 comprises: - a connector 9 capable of being connected to the electrical network,

[0065] - an inverter / rectifier 21 comprising here two switching arms 7, mounted in parallel and whose operation will be described below, and

[0066] - a primary inductive cell10 whose operation will be described below.

[0067] The electrical network 5 is here represented in the form of a direct voltage network but it can alternatively be an alternating voltage network providing for example a nominal effective voltage of 230V with a frequency of 50 Hz or 60 Hz. Such an alternating voltage electrical network can be single-phase or three-phase. Other voltages are possible, for example a single-phase voltage with an effective value of 120V and a frequency of 60Hz, a two-phase voltage with an effective value of 208V and a frequency of 60 Hz or a three-phase voltage of 240V and a frequency of 60 Hz, this list not being exhaustive. In the case where the network provides an alternating voltage, another inverter / rectifier not shown is provided between the network and the inverter / rectifier 21, this other inverter / rectifier providing for example a power factor correction function.

[0068] As can be seen in Figure 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 1OpF.

[0069] Each arm 7 of the primary sub-circuit 4 here comprises two controllable electronic switches 12, such as MOSFET, 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 duty cycle, one in opposition to the other with a dead time by the control unit 3.

[0070] 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 ai.

[0071] 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 a-2.

[0072] 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.

[0073] The primary inductive cell 10 can be formed by the series association of: an inductor allowing the generation of magnetic energy, and a capacitor, to form a resonant cell. The inductor has for example a value between 100pH and 100mH and the capacitor has a capacity between 10 nF and 1 mF. The inductor is for example made of Litz wire.

[0074] In the variant shown in Figure 1, the primary inductive cell 10 is formed by an inductance only. No physical capacitor is present, the presence in series of this capacitor with the inductance of the primary inductive cell 10 being emulated by the control of the switching arms 7 by the primary control unit 3 using the duty cycles ai and a2.

[0075] We will now describe an example of secondary sub-circuit 6 with reference to figure 1. This secondary sub-circuit 6 comprises a secondary inductive cell 20 for the contactless exchange of energy with the primary inductive cell 10, and an inverter / rectifier 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.

[0076] The inverter / rectifier 23 comprises in the example described two switching arms 24 arranged in parallel, each arm here comprising two switching cells 12 arranged on either side of a midpoint 25.

[0077] The first arm 24 thus comprises two switching cells 12 and a first midpoint 25 to which a terminal of the secondary inductive cell 20 is connected. Each of these two switching cells 12 is here controllable, one being controlled according to a duty cycle as while the other is controlled according to a duty cycle 1- as.

[0078] It can be seen from the figures that each switching cell 12 of the first switching arm here comprises a single controllable electronic switch 29. For each of these switching cells 12, a control unit 48 belonging to the control unit 3 is provided.

[0079] The second arm 24 also comprises two switching cells 12 and a second midpoint 25 to which the other terminal of the secondary inductive cell 20 is connected. Similar to the first arm, each switching cell 12 is controllable, one being controlled according to a duty cycle a4, while the other is controlled according to a duty cycle 1- a4.

[0080] The secondary inductive cell 20 is here formed by the series association of: an inductor allowing the magnetic energy from the primary inductive cell 10 to be recovered, and a capacitor, thus forming a resonant cell. In the example considered, the inductor has a value between 10pH and 10mH and the capacitor has a capacitance between 10 nF and 1 mF. Furthermore, the control unit 3 acts in the example described on the control of the inverter / rectifier 23 so as to vary the equivalent impedance RR ef at the terminals of the alternating input, defined between the two midpoints 25 of the switching arms 24, independently of the impedance on the continuous output of this inverter / rectifier 23.

[0081] The equivalent impedance RRef is represented by the ratio V / I where V is the voltage between the two midpoints 25, and I the intensity of the current flowing in the secondary inductive cell 20.

[0082] RRef has for example a value between 0.1 ' and 100 ' , in particular between 5 ' and 15 ' . For a given recharging configuration, this configuration being in particular determined by at least one of: 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 at the terminals of the electrical energy storage unit 2, RR ef can have a fixed value and this value is for example in the aforementioned range. From one load 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 can be modified, remaining in particular in the aforementioned range.

[0083] The inverter / rectifier 23 of Figure 1 is for example controlled as follows by the control unit 3, to carry out the impedance adaptation on the AC input of the inverter / rectifier 23:

[0084] - the first switching arm 24 switches at the frequency of the electrical energy exchanged without contact by inductive coupling and with a duty cycle of 50%, and

[0085] - the second switching arm 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 frequency of the electrical energy exchanged without contact, and with a duty cycle a4 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 inverter / rectifier 23. The switching cell 12 of the second switching arm 24 which is controllable is for example driven according to the duty cycle a4 according to the equation below:

[0086] OC4=(Rref X |I| ) / Vbatt where Vbatt denotes the voltage across the electrical energy storage unit 2.

[0087] Furthermore, although a single control unit 3 is shown, other embodiments are possible, for example the possibility that one control unit is dedicated to controlling the primary sub-circuit 4 and that another control unit is dedicated to controlling the secondary sub-circuit 6.

[0088] We will now describe in more detail with reference to Figure 2 the secondary sub-circuit 6 of Figure 1. As can be seen in this Figure 2, each switching cell 12 of the second switching arm 24 is here formed by two controllable electronic switches 29 arranged in parallel. Although only two controllable electronic switches 29 in parallel are shown, a greater number of controllable electronic switches in parallel is possible, for example 3, 4 or 5 switches. Each of these switches 29 is for example a MOSFET transistor or an IGBT, or a so-called HEMT transistor.

[0089] As can be seen in Figure 2, the control unit 3 comprises for each switching cell 12 a control unit 40 of this switching cell 12. This control unit 40 comprises:

[0090] - a 41 control unit, and

[0091] - a selection stage 42 arranged downstream of the control unit 41, allowing the differentiated control of the controllable switches of the switching cell 12.

[0092] The selection stage 42 here comprises two selection blocks 43, each block applying to a respective switch 29 of the switching cell 12 a control signal between the control electrode of said switch 29 and the same potential of the second switching arm.

[0093] As can be seen in Figure 2:

[0094] - the different selection blocks 43 associated with the switching cell 12 “high side” of the second switching arm 24 apply to a respective controllable electronic switch 29 of this switching cell a control signal between the control electrode of said switch and the midpoint 25 of the second switching arm, and

[0095] - the different selection blocks 43 associated with the switching cell 12 “low side” of the second switching arm 24 apply to a respective controllable electronic switch 29 of this switching cell a control signal between the control electrode of said switch and the lowest continuous potential.

[0096] It can be seen in Figure 2 that each selection block 43 can be produced using two signal transistors 45 and the assembly of these signal transistors 45 allows the controllable switch 29 to be opened via a current flowing in the intrinsic diode of this transistor 45.

[0097] Each selection block 43 here receives a control signal from the control unit 41 and a counter signal from a counter 46 of the control unit 40.

[0098] The counter 46 is for example a ring counter. The control signal is for example a square wave signal and the reception by the counter 46 of each rising edge in the control signal causes for example the designation by the counter 46 of the next controllable electronic switch 29 for conduction in the switching cell 12 and the sending to the selection stage 42 of the corresponding command. It is thus possible to divide the switching frequency applied to the switching cell 12 by the number of controllable electronic switches 29 in parallel, each of these switches 29 then switching at this fraction of the switching frequency applied to the switching cell 12.

[0099] The invention is not limited to the example which has just been described. In particular, although a single control unit 3 is shown, other embodiments are possible, for example the possibility that one control unit is dedicated to controlling the primary sub-circuit 4 and that another control unit is dedicated to controlling the secondary sub-circuit 6.

Claims

Claims 1. Secondary sub-circuit (6) for the electrical power supply of an electrical energy storage unit (2), this secondary sub-circuit (6) being capable of exchanging electrical energy without contact by inductive coupling with a primary sub-circuit (4) capable of being connected to a voltage network (5), and this sub-circuit (6) also being capable of being connected to an electrical energy storage unit (2), the secondary sub-circuit (6) comprising: - a secondary inductive cell (20) for 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 least two switching arms (24), namely: - a first switching arm switching at the frequency of the electrical energy induced in the secondary inductive cell (20) and, - a second switching arm (24) switching 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), the second switching arm comprising two switching cells (12) arranged on either side of a midpoint (25) of this second switching arm, at least one of these switching cells (12) comprising at least two controllable electronic switches (29) arranged in parallel.

2. Secondary sub-circuit according to claim 1, comprising a control unit (40) of the switching cell (12), this control unit (40) comprising a piloting unit (41) and a selection stage (42) arranged downstream of the piloting unit (41) and allowing the differentiated control of the controllable switches (29) of the switching cell (12).

3. Secondary sub-circuit according to claim 2, the selection stage (42) comprising two selection blocks (43), each block (43) applying to a respective switch (29) of the switching cell (12) a control signal between the control electrode of said switch and the same potential of the second switching arm.

4. Secondary sub-circuit according to claim 3, each selection block (43) receiving a control signal from the control unit (41) and a counter signal from a counter (46) of the control unit (40).

5. Secondary sub-circuit according to any one of the preceding claims, the switching cell (12) comprising between two and five controllable electronic switches (29) arranged in parallel, for example four controllable electronic switches (29) arranged in parallel.

6. Secondary sub-circuit according to any one of the preceding claims, the first switching arm (24) comprising two switching cells (12) each located on a respective side of the midpoint of this first switching arm (24), and each of these cells (12) comprising a single controllable electronic switch (29).

7. Secondary sub-circuit according to any one of the preceding claims, each switching cell (12) of the second switching arm (24) comprising several controllable electronic switches (29) arranged in parallel, in particular between two and five controllable electronic switches (29) arranged in parallel.

8. Secondary sub-circuit according to any one of the preceding claims, the secondary inductive cell (20) being constituted by the series association of a capacitor and an inductance.

9. Secondary sub-circuit according to any one of claims 1 to 7, the secondary inductive cell (20) being constituted by an inductance, the switching arms (24) of the inverter / rectifier (23) being controlled so that the voltage across the terminals of the winding of the secondary inductive cell (20) emulates the presence of a capacitor connected in series with the inductance.

10. Secondary sub-circuit according to any one of the preceding claims, the secondary inductive cell (20) having a resonance frequency between 79 kHz and 90 kHz, being in particular equal to 85 kHz.

11. Electrical power supply circuit (1) of 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 - the secondary sub-circuit (6) according to any one of the preceding claims, the primary sub-circuit (4) comprising: - a primary inductive cell (10) for contactless exchange by inductive coupling of electrical energy with the secondary inductive cell (20), and - an inverter / rectifier (21) comprising at least two switching arms (7), each switching arm (7) comprising two controllable electronic switches (12) arranged on either side of a midpoint (15).

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

13. Device for the electrical power supply of an electrical energy storage unit (2), comprising: - the electrical circuit according to claim 11, - 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 the 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.

Images