Electrical power supply circuit of a vehicle electrical energy storage unit

Abstract

Secondary sub-circuit (6) for supplying power to an electrical energy storage unit (2), this secondary sub-circuit 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, and this secondary sub-circuit also being capable of being connected to an electrical energy storage unit, this sub-circuit comprising: - three secondary inductive cells (20), each capable of exchanging electrical energy without contact by inductive coupling with a respective primary inductive cell (10) of the primary sub-circuit, - an inverter / rectifier (23), receiving on its AC input the three-phase voltage corresponding to the three secondary inductive cells (20) and receiving on its DC input a voltage suitable for being connected to the terminals of the electrical energy storage unit (2),the inverter / rectifier (23) comprising a plurality of switching arms (24) mounted in parallel, each switching arm (24) comprising two controllable electronic switches (12) mounted on either side of a midpoint (25), and - a control unit (3) configured to control the controllable electronic switches (12) of the switching arms (24) so ​​as to achieve impedance matching of the impedance at the AC input of this inverter / rectifier (23), independently of the impedance of the electrical energy storage unit (2). Abbreviated figure: Fig. 1,

Description

Title of the invention: Electrical power supply circuit for a vehicle 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 inductive coupling, whether the vehicle is stationary or moving. This contactless power supply is achieved using magnetically coupled, distant electrical subcircuits tuned to the same resonant frequency. Each magnetically coupled subcircuit employs an LC-type resonant cell. However, to transmit a satisfactory power level, particularly several kW, it is necessary to operate at high frequencies, specifically on the order of 85 kHz or higher, for the resonant frequency of each resonant subcircuit. It is therefore desirable to increase the efficiency of such a contactless power supply.

[0004] The invention aims to meet this need and achieves this, according to one of its aspects, by means of a secondary sub-circuit for the 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, this sub-circuit comprising:

[0005] - three secondary inductive cells, each capable of exchanging energy contactless electrical coupling via inductive coupling with a respective primary inductive cell of the primary sub-circuit

[0006] - an inverter / rectifier, receiving on its AC input the three-phase voltage corresponding to the three secondary inductive cells and receiving on its DC input a voltage suitable for connection to the terminals of the electrical energy storage unit,

[0007] the inverter / rectifier comprising a plurality of switching arms mounted in parallel, each switching arm comprising two controllable electronic switches mounted on either side of a midpoint, and

[0008] - a control unit configured to control electronic switches controllable switching arms so as to achieve impedance matching of the impedance on the AC input of this inverter / rectifier, independently of the impedance of the electrical energy storage unit.

[0009] Such a secondary sub-circuit implementing three secondary inductive cells exhibits better efficiency than when using a single secondary inductive cell.

[0010] The control of the switching arms by the control unit can allow the voltage across each secondary inductive cell to be equal to the product of the current flowing in that secondary inductive cell multiplied by the value of the reference load impedance.

[0011] The three secondary inductive cells can be phase-shifted two by two by 120° electrically.

[0012] In the context 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.

[0013] According to a first embodiment, the three secondary inductive cells can be arranged in a star configuration. A star configuration, compared to an H-bridge configuration, allows for a reduced cost in terms of controllable electronic switches.

[0014] According to a first variant of this first example of implementation, the inverter / rectifier may include three switching arms, in particular only three switching arms, and each terminal of the star connection may be connected to a respective midpoint of one of the switching arms without the interposition of an inductance.

[0015] For the purposes of this application, "inductance" means an inductance other than a parasitic inductance.

[0016] According to a second variant of this first embodiment, the inverter / rectifier may comprise six switching arms, or in particular only six switching arms. Each terminal of the star connection may be connected to two respective midpoints of two switching arms with an interposed inductance. For example, two inductances are associated with each terminal of the star connection; each of said terminals is then connected by one of these two inductances to the midpoint of one of the two switching arms and by the other of these two inductances to the midpoint of the other of the two switching arms.

[0017] According to a second embodiment, the three secondary inductive cells can be arranged in a delta configuration.

[0018] A delta connection, compared to other connections such as a star connection or an H-bridge connection, allows, at a reduced cost in terms of controllable electronic switches, a higher voltage dynamic on the AC input of the inverter / rectifier, and therefore a higher impedance value on this AC input, if necessary.

[0019] According to a first variant of this second embodiment example, the inverter / rectifier may comprise three switching arms, in particular only three switching arms, each terminal of the delta assembly being connected to a respective midpoint of one of the switching arms without the interposition of an inductance.

[0020] According to a second variant of this second embodiment, the inverter / rectifier may comprise six switching arms, or in particular only six switching arms. Each terminal of the star connection may be connected to two respective midpoints of two switching arms with an interposed inductance. For example, two inductances are associated with each terminal of the delta connection. Each of these terminals is then connected by one of these two inductances to the midpoint of one of the two switching arms and by the other of these two inductances to the midpoint of the other of the two switching arms.

[0021] According to a third embodiment, the inverter / rectifier can define three H-bridges, each H-bridge comprising two switching arms, and being dedicated to a secondary inductive cell, the secondary inductive cell being mounted between the midpoints of the two switching arms of a respective H-bridge without the interposition of an inductor. An H-bridge configuration has the advantage over delta or star configurations of being able to drive the three phases independently with a specific impedance for each phase.

[0022] According to a fourth embodiment, the inverter / rectifier can define three H-bridges, each H-bridge comprising three switching arms, in particular consisting of three switching arms, and being dedicated to a secondary inductive cell, said secondary inductive cell having:

[0023] - a first terminal connected to two respective midpoints of two of the three arms of switching of the H-bridge with the interposition of an inductor, and

[0024] - a second terminal connected to the midpoint of the other of the three switching arms of the H-bridge without the interposition of an inductor.

[0025] There are thus two inductances per H-bridge.

[0026] According to a variant of this fourth embodiment, each H-bridge comprises four switching arms, specifically consisting of four switching arms, and is dedicated to a secondary inductive cell, said secondary inductive cell having:

[0027] - a first terminal connected to two respective midpoints of two of the four arms switching of the H-bridge with interposition of an inductor, and

[0028] - a second terminal connected to two respective midpoints of two other terminals four switching arms of the H-bridge with interposition of an inductor.

[0029] There are thus four inductances per H-bridge.

[0030] According to the first variant of the first embodiment, or the first variant of the second embodiment, or according to the third embodiment, at least one of the switching arms whose midpoint is connected to a terminal of the star or delta connection or to a terminal of a secondary inductive cell may comprise, instead of a single electronic switch controllable on either side of its midpoint, several electronic switches controllable in parallel, in particular two electronic switches controllable in parallel, on each side of its midpoint. The use of several electronic switches controllable in parallel makes it possible to distribute the current conduction and switching stress between these different electronic switches controllable. In practice, this results in a reduction of the switching frequency per electronic switch controllable.Less complex and / or less expensive controllable electronic switches are thus used in the switching cell. Where applicable, each switching arm, according to the variants or embodiments described above, may comprise several controllable electronic switches in parallel, in particular two controllable electronic switches in parallel, on either side of its midpoint. These switching arms with several controllable electronic switches on either side of their midpoint are, for example, implemented according to the teachings of the application filed in France on November 30, 2023, by the Applicant under number 2313325.

[0031] The various controllable electronic switches arranged in parallel within the same switching arm can be controlled by a control unit as described in this application filed in France on November 30, 2023 by the Applicant under number 2313325. The advantage of such an arrangement is its reduced cost compared to an arrangement requiring more complex controllable electronic switches.

[0032] The presence of an inductance between:

[0033] - a midpoint of a switching arm, and

[0034] - a terminal of an inductive cell or a terminal of a star or in triangle,

[0035] for one or more switching arms, can be carried out in accordance with the teaching of the application filed in France on May 7, 2024 by the Applicant under number FR 2404802.

[0036] According to the second variant of the first embodiment, or the second variant of the second embodiment, or according to the fourth embodiment, the switching arms connected to the same terminal of the star or delta connection, or to a terminal of the secondary inductive cell, by means of an inductor, can be of a number equal to N, and each of these N arms can be controlled so as to switch at the same frequency and with a phase shift of 360 / N° from one arm to the next. 360 / N° thus represents the electrical control angle shift from one arm to the next. The phase shift of 360 / N° introduced between these switching arms allows each inductor interposed between the midpoint of this arm and a terminal of the connection or the secondary inductive cell to be subjected to an alternating voltage that produces a ripple in the current seen by the electronic switches of the N switching arms.Due to this current ripple, the electronic switches in these N switching arms switch to the conducting state to carry a negative current, thereby reducing switching losses.

[0037] According to these second variants of the first and second embodiments, or according to the fourth embodiment, impedance matching can be achieved by switching these N arms at frequencies higher than that of the electrical energy transmitted without contact by inductive coupling, for example, 5 or 10 times higher than 85 kHz, for example, at a few hundred kHz, without the switching at these high frequencies generating excessive losses. The current ripple advantageously does not affect the shape of the current flowing in the secondary inductive cells, given the chosen values ​​for the inductances and the resonant frequency of the secondary inductive cells.This allows us to benefit from the advantages of impedance matching, which reduces, for a given current value in each secondary inductive cell, the current flowing in the primary inductive cell associated with that secondary inductive cell, thus increasing the efficiency of electrical energy exchange. These advantages remain available even though impedance matching requires the use of high switching frequencies in the N switching arms, since switching losses are significantly reduced.

[0038] Each non-parasitic inductance has for example the same value between lOOnH and lOpH.

[0039] N can be equal to two, three, four or more.

[0040] Each of the N inductances can be dedicated to a respective arm, so as to connect the midpoint of said arm to the terminal of the star or delta connection or to a terminal of the secondary inductive cell. There is thus one inductance for each of these switching arms.

[0041] All or part of these inductors can be magnetically coupled via a single magnetic core. This reduces the number of magnetic components required for mounting the inductors. Alternatively, the inductors are not coupled to each other, each having its own magnetic core.

[0042] In the second variant of the first or second embodiment, or in the fourth embodiment, the secondary subcircuit may include a capacitor in parallel with each controllable electronic switch belonging to a switching arm whose midpoint is connected to a terminal of the star or delta connection, or to a terminal of a secondary inductive cell, by means of an inductor. The presence of this capacitor, whose value is, for example, between 100pF and 100F, reduces losses during the switching of the corresponding controllable electronic switch to the off state.

[0043] In all the above, each secondary inductive cell can be constituted by the series association of a capacitor and an inductor.

[0044] Alternatively, in all the foregoing, each secondary inductive cell may be constituted by an inductor, the switching arms of the inverter / rectifier being controlled such that each phase of the voltage at the AC input of this inverter / rectifier emulates the presence of a capacitor connected in series with a secondary inductive cell. Such a control method for obtaining this emulation is described in the application filed in France on June 2, 2023, by the Applicant under number 23 05573.

[0045] In all the above, each secondary inductive cell may have a resonance frequency between 79 kHz and 90 kHz, in particular being equal to 85 kHz.

[0046] In all the foregoing, the secondary sub-circuit may include the electrical energy storage unit. The latter may be a lithium-ion type battery. This battery may, for example, have a nominal voltage of 12V, 48V, 60V or more, for example greater than 300V, for example 400V, 800V or 1000V.

[0047] According to either of the implementation examples, the secondary subcircuit may include, for each secondary inductive cell, at least one of the following:

[0048] - of a capacitor mounted between the first terminal of the secondary inductive cell and the mass,

[0049] - of a capacitor mounted between the second terminal of the secondary inductive cell and the mass, and

[0050] - of a capacitor mounted between the first terminal of the secondary inductive cell and the second terminal of the secondary inductive cell.

[0051] This or these capacitors allow high-frequency noise to be filtered in the secondary sub-circuit.

[0052] Where applicable, each of the three aforementioned capacitors is simultaneously present in the secondary sub-circuit for each secondary inductive cell.

[0053] Each capacitor mounted between a terminal of the secondary inductive cell and ground is, for example, a capacitance X.

[0054] The capacitor mounted between the two terminals of the secondary inductive cell is, for example, a Y-capacitor.

[0055] If applicable:

[0056] - a series assembly of a capacitor and a resistor is connected in parallel of the capacitor mounted between the first terminal of the secondary inductive cell and ground, and / or

[0057] - a series assembly of a capacitor and a resistor is connected in parallel of the capacitor mounted between the second terminal of the secondary inductive cell and ground, and / or

[0058] - a series assembly of a capacitor and a resistor is connected in parallel of the capacitor mounted between the first terminal of the secondary inductive cell and the second terminal of the secondary inductive cell.

[0059] The invention also relates, according to another aspect, to a power supply circuit for an electrical energy storage unit, this power supply circuit comprising:

[0060] - a primary sub-circuit, suitable for connection to a voltage network, and

[0061] - the secondary sub-circuit as defined above,

[0062] the primary sub-circuit comprising:

[0063] - three primary inductive cells for contactless exchange by inductive coupling of electrical energy with a respective secondary inductive cell of the secondary sub-circuit, and

[0064] - an inverter / rectifier comprising at least three switching arms, each switching arm comprising two controllable electronic switches arranged on either side of a midpoint.

[0065] Each pair of secondary inductive cell / primary inductive cell is advantageously chosen so that these two cells have the same resonance frequency, in particular a resonance frequency between 79 kHz and 90 kHz, for example being on the order of 85 kHz.

[0066] In all the foregoing, each primary inductive cell can 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, each primary inductive cell can be constituted by an inductor, the switching arms of the inverter / rectifier of the primary subcircuit being controlled so that each phase of the voltage on the AC input of this inverter / rectifier emulates the presence of a capacitor connected in series with the primary inductive cell.

[0067] 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. This other inverter / rectifier rectifies the AC voltage received from the grid when the load is drawn from an AC voltage grid. This other inverter / rectifier can then perform a power factor correction function. Such a correction ensures, in a known manner, that the current drawn from the grid is as close as possible to a perfect sine wave at the grid frequency. This reduces reactive current and subharmonics, which increase energy losses during conduction.

[0068] The primary inductive cell can be integrated into a load mat placed in or on the ground, as described in the application filed by the present Applicant on 11 / 09 / 2023 under number 2309545.

[0069] In all the above, the electrical network provides, for example, a nominal effective voltage of 230V with a frequency of 50 Hz or 60 Hz. The electrical network is, for example, single-phase. The electrical network is, for example, a regional or national electrical network. Alternatively, it may be an independent local network, comprising, for example, one or more batteries powered by energy sources such as wind turbines, solar panels, fuel cells, or hydroelectric generators.

[0070] Alternatively, the electrical network can supply a direct current voltage.

[0071] The control unit can control the switching arms of the primary sub-circuit.

[0072] In all the above, the control unit can be configured to control the different switching arms so as to selectively perform:

[0073] - a charge of the electrical energy storage unit from the voltage network, Or

[0074] - a load on the voltage network or any other electrical load on the network side from the electrical energy storage unit.

[0075] Thus, depending on the need, the exchange of electrical energy can take place in one direction or the other.

[0076] When the electrical circuit allows a load from the voltage network or any other electrical load on the network side from the electrical energy storage unit, the inverter / rectifier of the primary subcircuit may have a structure identical to that of the inverter / rectifier of the secondary subcircuit.

[0077] Thus, when the inverter / rectifier of the secondary sub-circuit has a structure according to the first, respectively second, respectively third, respectively fourth implementation example, the inverter / rectifier of the primary sub-circuit has, for example, the same structure according to the first, respectively second, respectively third, respectively fourth implementation example.

[0078] In all the foregoing, each switching arm comprises controllable electronic switches, in particular exclusively electronic switches that are controllable, and each controllable electronic switch is, for example, a transistor, for example a bipolar transistor, MOSFET or IGBT, or a thyristor. The MOSFET transistor is, for example, made of SiC. Alternatively, it may be a high electron mobility transistor (HEMT) based on GaN. Each controllable electronic switch is, for example, bidirectional.

[0079] In all the foregoing, the control unit may be a digital processing circuit, for example an ASIC (Application-specific integrated circuit) or a microcontroller. This control unit may control all the switching arms of the electrical circuit, whether they belong to the primary or secondary subcircuit.

[0080] The control unit may alternatively include a primary sub-circuit control module and a secondary sub-circuit control module.

[0081] Alternatively, each sub-circuit has its own control unit, which may be a digital processing circuit such as a microcontroller.

[0082] 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.

[0083] The invention also relates, according to another aspect, to a device for supplying power to an electrical energy storage unit, comprising:

[0084] - 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

[0085] - 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.

[0086] 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.

[0087] In all the above, the inductive cells can be configured for an exchange of electrical energy between the primary sub-circuit and the secondary sub-circuit with a power whose value is between 3 kW and 50 kW, for example a power whose value is equal to 7 kW or 11 kW.

[0088] The invention will be better understood upon reading the following description of non-limiting examples of its implementation and upon examination of the accompanying drawing in which:

[0089] [Fig-1] schematically represents an electrical power supply circuit comprising a secondary sub-circuit according to a first variant of a first example of implementation of the invention,

[0090] [Fig.2] schematically represents a secondary sub-circuit of an electrical power supply circuit according to a second variant of the first embodiment of the invention,

[0091] [Fig.3] schematically represents a secondary sub-circuit of an electrical power supply circuit according to a first variant of a second example of an implementation of the invention,

[0092] [Fig.4] schematically represents a secondary sub-circuit of an electrical power supply circuit according to a second variant of the second embodiment of the invention,

[0093] [Fig. 5] schematically represents a secondary sub-circuit of a power supply circuit according to a third embodiment of the invention,

[0094] [Fig. 6] schematically represents a secondary sub-circuit of a power supply circuit according to a first variant of a fourth embodiment of the invention, and

[0095] [Fig.7] schematically represents a secondary sub-circuit of an electrical power supply circuit according to a second variant of the second example of implementation of the invention.

[0096] Figure 1 shows an electrical power supply circuit 1 of 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.

[0097] This power supply circuit includes:

[0098] - a control unit 3,

[0099] - a primary sub-circuit 4, suitable for connection to a voltage network 5, and

[0100] - a secondary sub-circuit 6, comprising the electrical energy storage unit 2.

[0101] 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.

[0102] The control unit 3 is for example a microcontroller or any digital processing unit.

[0103] In the example considered, the primary sub-circuit 4 comprises:

[0104] - a connector 9 suitable for being connected to the electrical network,

[0105] - an inverter / rectifier 21 comprising here three switching arms 7, mounted in parallel, and whose operation will be described below, and

[0106] - three primary inductive cells 10 whose operation will be described below. In the example considered, these three primary inductive cells 10 are arranged in a star configuration.

[0107] The electrical network 5 is represented here as a direct current (DC) network, but it can alternatively be an alternating current (AC) network supplying, for example, a nominal RMS voltage of 230 V with a frequency of 50 Hz or 60 Hz. Such an AC network can be single-phase or three-phase. Other voltages are possible, for example, a single-phase voltage with an RMS value of 120 V and a frequency of 60 Hz, a two-phase voltage with an RMS value of 208 V and a frequency of 60 Hz, or a three-phase voltage of 240 V and a frequency of 60 Hz; this list is not exhaustive. In the case where the network supplies an alternating current (AC) 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.

[0108] As can be seen in [Fig.1], a capacitor 15 can be arranged in parallel with the three switching arms 7. The latter has, for example, a capacitance between IpF and ImF, for example of lOpF.

[0109] Each arm 7 of the primary subcircuit 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 by means of a same cyclic ratio, one in opposition to the other with a dead time by control unit 3.

[0110] A first arm 7 thus comprises two controllable electronic switches 12 and a first midpoint 8 to which a first terminal 18 of the first primary inductive cell 10 (which also constitutes a terminal of the star connection of the primary inductive cells 10) is connected without the intermediary of an inductor, and these two controllable electronic switches 12 are controlled according to a duty cycle ab

[0111] A second arm 7 thus comprises two controllable electronic switches 12 and a second midpoint 8 to which a first terminal 18 of the second primary inductive cell 10 (which also constitutes a terminal of the star arrangement of the primary inductive cells 10) is connected without the intermediary of an inductance and these two controllable electronic switches 12 are controlled according to a duty cycle a2.

[0112] A third arm 7 thus comprises two controllable electronic switches 12 and a third midpoint 8 to which a first terminal 18 of the third primary inductive cell 10 (which also constitutes a terminal of the star arrangement of the primary inductive cells 10) is connected without the intermediary of an inductance, and these two controllable electronic switches 12 are controlled according to a duty cycle a3.

[0113] As can be seen in [Fig. 1], each primary inductive cell 10 can be formed by the series connection of an inductor for generating magnetic energy and a capacitor to form a resonant cell. The inductor may, for example, have a value between 10H and 10MH, and the capacitor may have a capacitance between 10 nF and 1 mF. The inductor may, for example, be made of Litz wire.

[0114] In an unshown embodiment, each primary inductive cell 10 is formed by an inductance only. No physical capacitor is present; the presence of this capacitor in series with the inductance of the primary inductive cell 10 is emulated by the control of the switching arms 7 by the primary control unit 3 using the duty cycles ab a2 and a3. Here again, the inductance is, for example, made of Litz wire.

[0115] The second terminals 19 of the primary inductive cells 10 are here connected together so as to define a neutral point.

[0116] We will now describe an example of a secondary subcircuit 6 with reference to [Fig. 1]. This secondary subcircuit 6 comprises three secondary inductive cells 20 for contactless energy exchange with a respective 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 cells 20), so as to vary this impedance independently of the impedance of the electrical energy storage unit 2. The voltage across each secondary inductive cell 20 can then be equal to the product of the voltage across the electrical energy storage unit 2 by the duty cycle applied to rectify the voltage across said secondary inductive cell.

[0117] The three secondary inductive cells 20 are here mounted in a star configuration.

[0118] The inverter / rectifier 23 in the described example comprises three switching arms 24 arranged in parallel, each arm here comprising two controllable electronic switches 12 arranged on either side of a midpoint 25.

[0119] Each arm 24 of the secondary subcircuit 6 here comprises two controllable electronic switches 12, such as MOSFET, IGBT or bipolar transistors, or thyristors, arranged on either side of a midpoint 25. 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.

[0120] A first arm 24 thus comprises two controllable electronic switches 12 and a first midpoint 25 to which a first terminal 26 of the first secondary inductive cell 20 (which also constitutes a terminal of the star arrangement of the secondary inductive cells 20) is connected without the intermediary of an inductance, and these two controllable electronic switches 12 are controlled according to a duty cycle a4.

[0121] A second arm 24 thus comprises two controllable electronic switches 12 and a second midpoint 25 to which a first terminal 26 of the second secondary inductive cell 20 (which also constitutes a terminal of the star arrangement of the secondary inductive cells 20) is connected without the intermediary of an inductance and these two controllable electronic switches 12 are controlled according to a duty cycle a5.

[0122] A third arm 24 thus comprises two controllable electronic switches 12 and a third midpoint 25 to which a first terminal 26 of the third secondary inductive cell 20 (which also constitutes a terminal of the star arrangement of the secondary inductive cells 20) is connected without the intermediary of an inductance and these two controllable electronic switches 12 are controlled according to a duty cycle a6.

[0123] The second terminals 27 of the secondary inductive cells 20 are here connected together so as to define a neutral point.

[0124] As can be seen in [Fig. 1], each secondary inductive cell 20 can be formed by the series connection of an inductor for generating magnetic energy and a capacitor to form a resonant cell. The inductor may, for example, have a value between 10H and 10MH, and the capacitor may have a capacitance between 10 nF and 1 mF. The inductor may, for example, be made of Litz wire.

[0125] In the example considered, a primary inductive cell 10 exchanges electrical energy without contact by inductive coupling with a secondary inductive cell 20, and each primary inductive cell 10 / secondary inductive cell 20 pair has the same resonance frequency of 85 kHz, and the exchange of electrical energy without contact by inductive coupling takes place at this resonance frequency and according to a coupling coefficient k.

[0126] 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 on the alternating input, independently of the impedance on the direct output of this inverter / rectifier 23. Each secondary inductive cell 20 is then loaded by an equivalent impedance RRef.

[0127] For each secondary inductive cell 20, the equivalent impedance RRef is represented by the ratio V / I where V is the line voltage and I is the line current intensity.

[0128] RRef, for example, has a value between 0.1 'Q and 100 'Q, in particular between 5Q and 30Q. 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.

[0129] We will now describe, with reference to [Fig.2] a secondary sub-circuit 6 according to a variant of what has just been described for this first example of implementation.

[0130] This secondary subcircuit differs from the one just described in that the inverter / rectifier 23 no longer comprises three switching arms 24, but six switching arms 24. Each first terminal 26 of a secondary inductive cell 20 is then connected to two midpoints 25 of two switching arms 24 via two inductors 28. Each inductor 28 has, for example, the same value between lOOnH and lOpH. The two inductances 28 associated with the same first terminal 26 of a secondary inductive cell 20 have for example a common core, being then coupled, or they each have their own core.

[0131] The inverter / rectifier 23 of [Fig.2] is for example controlled as follows by the control unit 3, to achieve impedance matching on the AC input of the inverter / rectifier 23 when charging the electrical energy storage unit 2.

[0132] For each secondary inductive cell 20, the control unit 3 controls the two arms 24 whose midpoint 25 is connected to the first terminal 26 of this secondary inductive cell 20a so that they switch at the same frequency and with a phase shift of 180° from one arm to the other. Each of these two arms 24 switches, for example, at a frequency of 425 kHz.

[0133] Two arms 24 associated with the first secondary inductive cell 20 are, for example, controlled according to the duty cycle a4, two arms 24 associated with the second secondary inductive cell 20 are controlled according to a duty cycle a5, and two arms 24 associated with the third secondary inductive cell 20 are controlled according to a duty cycle a6, and these duty cycles are chosen so as to impose the impedance RRef such that:

[0134] vc4 = RRef (a4-a5) x

[0135] [Math.l] Vc5 = R&f = ( «5- «6 ) X ybatt

[0136] [Math.2] V c6 = R R e fa b - a4 ) x V ha(t

[0137] where vc4, vc5 and vc6 correspond to the line voltages between the respective phases.

[0138] Circuit 1 in Figures 1 and 2 can allow a load on the electrical network 5 or on any other electrical load on the grid side from the electrical energy storage unit 2. This reversibility is made possible by the fact that the inverter / rectifier 7 and the inverter / rectifier 23 have the same structure. In particular, in the case of [Fig. 2], inductors similar to the inductors 28 can be arranged between the first terminal 18 of the primary inductive cells 10 and each midpoint 8 of a switching arm 7 to which this first terminal 18 is connected.

[0139] We will now describe, with reference to [Fig.3] and 4, two variants of a secondary sub-circuit 6 according to a second example of implementation of the invention.

[0140] This second example of implementation differs from the first example in that the three secondary inductive cells 20 (and similarly the three primary inductive cells 10, although this is not shown in Figures 3 and 4) are arranged in a delta configuration.

[0141] According to a first variant of this second embodiment, and similarly to what has been described with reference to the first variant of the first embodiment of [Fig.1], the inverter / rectifier 23 comprises only three switching arms 24, and each terminal of the delta assembly is connected to a respective midpoint 25 of one of the switching arms 24 without the interposition of an inductance.

[0142] According to a second variant of this second embodiment, and similarly to what has been described with reference to the second variant of the first embodiment of [Fig. 2], the inverter / rectifier comprises six switching arms 24, and each terminal 26 of the star connection can be connected to two respective midpoints 25 of two switching arms 24 with an interposed inductor 28. Two inductors 28 are, for example, associated with each terminal of the delta connection, each of said terminals then being connected:

[0143] - by one of these two inductances 28 at the midpoint 25 of one of the two arms of switching 24, and

[0144] - by the other of these two inductances at the midpoint of the other of the two arms of switching.

[0145] We will now describe, with reference to [Fig. 5], a secondary sub-circuit 6 according to a third embodiment of the invention. According to this third embodiment, the secondary inductive cells 20 are not connected in a star or delta configuration, but are connected independently via H-bridges dedicated to said secondary inductive cells. In this example, three H-bridges 40 are provided, and each H-bridge 40 consists of two switching arms 24. Each secondary inductive cell 20 is connected between the midpoints 25 of the two switching arms 24 of the H-bridge 40 dedicated to it, without the interposition of an inductor. The primary sub-circuit 4 can, according to this third embodiment, have a structure symmetrical to that shown in [Fig. 5].

[0146] We will now describe, with reference to Figures 6 and 7, a secondary sub-circuit 6 according to two variants of a fourth example of implementation of the invention.

[0147] According to the first variant of [Fig. 6], the inverter / rectifier 23 defines three H-bridges 40. Each H-bridge 40 is here constituted by three switching arms 23, and it is dedicated to a secondary inductive cell 20. This secondary inductive cell 20 has:

[0148] - a first terminal 26 connected to two respective midpoints 25 of two of the three switching arm of the H-bridge 40 with interposition of an inductor 28, and

[0149] - a second terminal 27 connected to the midpoint 25 of the other of the three arms of switching of the bridge in H 40 without the interposition of an inductance.

[0150] There are thus two inductances 28 per H-bridge 40, and only one terminal per secondary inductive cell 20 is connected to midpoints via a respective inductance 28.

[0151] According to the variant in [Fig. 7], each H-bridge 40 consists of four switching arms 24 and is dedicated to a secondary inductive cell 20. This secondary inductive cell has:

[0152] - a first terminal 26 connected to two respective midpoints 25 of two of the four switching arm of the H-bridge with interposition of an inductor 28, and

[0153] - a second terminal 27 connected to two respective midpoints 25 of two other terminals four switching arms of the H-bridge with interposition of an inductance 28.

[0154] There are thus four inductances 28 per H-bridge 40. For each inductive cell 20, each terminal 26, 27 is connected to midpoints via a respective inductance 28.

[0155] The invention is not limited to the example just 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 another control unit is dedicated to controlling the secondary sub-circuit 6.

[0156] Furthermore, although not shown in the example of Figures 1, 3 and 5, each switching arm 24 may, instead of a single controllable electronic switch 12 arranged on each side of a midpoint 25, comprise several controllable electronic switches 12 arranged in parallel, on each side of the midpoint 25.

Claims

Demands

1. Secondary sub-circuit (6) for supplying power to an electrical energy storage unit (2), this secondary sub-circuit 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, and this secondary sub-circuit also being capable of being connected to an electrical energy storage unit, this secondary sub-circuit (6) comprising: - three secondary inductive cells (20), each capable of exchanging electrical energy without contact by inductive coupling with a respective primary inductive cell (10) of the primary sub-circuit, - an inverter / rectifier (23), receiving on its AC input the three-phase voltage corresponding to the three secondary inductive cells (20) and receiving on its DC input a voltage suitable for being connected to the terminals of the electrical energy storage unit (2),the inverter / rectifier (23) comprising a plurality of switching arms (24) mounted in parallel, each switching arm (24) comprising two controllable electronic switches (12) mounted on either side of a midpoint (25), and - a control unit (3) configured to control the controllable electronic switches (12) of the switching arms (24) so ​​as to achieve 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).

2. Secondary subcircuit according to claim 1, the three secondary inductive cells (20) being arranged in a star configuration.

3. Secondary subcircuit according to claim 2, the inverter / rectifier (23) comprising three switching arms (24), each terminal of the star arrangement being connected to a respective midpoint (25) of one of the switching arms (24) without the interposition of an inductance.

4. Secondary sub-circuit according to claim 2, the inverter / rectifier (23) comprising six switching arms (24), each terminal of the star arrangement being connected to two midpoints (25) respective of two switching arms (24) with interposition of an inductance (28).

5. Secondary subcircuit according to claim 1, the three secondary inductive cells (20) being arranged in a delta configuration.

6. Secondary subcircuit according to claim 5, the inverter / rectifier (23) comprising three switching arms (24) each terminal of the delta assembly being connected to a respective midpoint (25) of one of the switching arms without the interposition of an inductance (28).

7. Secondary subcircuit according to claim 5, the inverter / rectifier (23) comprising six switching arms (24), each terminal of the star arrangement being connected to two respective midpoints (25) of two switching arms (24) with interposition of an inductance (28).

8. Secondary subcircuit (6) according to claim 1, the inverter / rectifier (23) defining three H-bridges (40), each H-bridge (40) comprising two switching arms (24) and being dedicated to a secondary inductive cell (20), the secondary inductive cell (20) being mounted between the midpoints (25) of the two switching arms of a respective H-bridge (40) without the interposition of an inductance (28).

9. Secondary subcircuit according to claim 1, the inverter / rectifier (23) defining three H-bridges (40), each H-bridge (40) comprising three switching arms (24), and being dedicated to a secondary inductive cell (20), said secondary inductive cell (20) having: - a first terminal (26) connected to two respective midpoints (25) of two of the three switching arms of the H-bridge with interposition of an inductance (28), and - a second terminal (27) connected to the midpoint (25) of the other of the three switching arms of the H-bridge without the interposition of an inductance.

10. Secondary sub-circuit according to claim 1, the inverter / rectifier (23) defining three H-bridges (40), each H-bridge comprising four switching arms (24) and being dedicated to a secondary inductive cell (20), said secondary inductive cell having: - a first terminal (26) connected to two respective midpoints of two of the four switching arms of the H-bridge with interposition of an inductance (28), and - a second terminal (27) connected to two respective midpoints of two other of the four switching arms of the H-bridge with interposition of an inductance.

11. Secondary subcircuit according to any one of the preceding claims, each secondary inductive cell (20) having a resonant frequency between 79 kHz and 90 kHz, in particular being equal to 85 kHz.

12. Power supply circuit (1) of an electrical energy storage unit (2), said power supply circuit comprising: - a primary sub-circuit (4), suitable for connection to a voltage network (5), and - the secondary sub-circuit (6) according to any one of the preceding claims, the primary sub-circuit comprising: - three primary inductive cells (10) for the contactless exchange by inductive coupling of electrical energy with a respective secondary inductive cell (20) of the secondary sub-circuit (6), and - an inverter / rectifier (21) comprising at least three switching arms (7), each switching arm (7) comprising two controllable electronic switches (12) arranged on either side of a midpoint (8).

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

14. Device for supplying power to an electrical energy storage unit (2), comprising: - the electrical circuit according to claim 12, - a charging station for a hybrid or electric vehicle, in which the primary sub-circuit (4) of the electrical circuit (1) is disposed or to which the primary sub-circuit (4) is electrically connected, and - a component suitable for use in a hybrid or electric vehicle, in which is disposed the secondary sub-circuit (6) of the electrical circuit (1).

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