Power supply circuit for electrical energy storage unit of vehicle

Abstract

A charging circuit (1) comprises an inductance unit (16) for contactless energy exchange, an electrical energy storage unit (20), a voltage inverter / rectifier (7) connected to the energy storage unit (20) and connectable to a phase of an electric machine (8) of an electric vehicle, where a first terminal of the inductance unit (16) is connected to a first switching arm of the voltage inverter / rectifier (7), and a second terminal of the inductance unit (16) is connected to a second switching arm of the voltage inverter / rectifier (7). A second terminal of the inductance unit (16) is connected to a second switching arm of the voltage inverter / rectifier (7).

Description

Technical Field

[0001] The invention relates to a contactless power supply circuit for an electric energy storage unit of a vehicle. Background Art

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

[0003] It is known to use contactless transmission by inductive coupling to supply power to an electrical energy storage unit of a vehicle when the vehicle is stationary or when it is moving. This power supply by contactless transmission is then carried out with the aid of remote electronic subcircuits that are magnetically coupled and tuned to the same resonant frequency. The magnetically coupled subcircuits each implement an LC resonant unit.

[0004] A known solution consists in applying an AC voltage across the terminals of a primary inductor unit coupled to a secondary inductor unit by inductive coupling, the AC voltage induced across the terminals of the secondary inductor unit being rectified to power an electrical energy storage unit (eg an electric vehicle battery).

[0005] In known solutions, a DC / AC converter dedicated to voltage rectification for charging an electrical energy storage unit is required. This DC / AC converter is a complement to existing converters (also known as inverter / rectifiers) for supplying AC voltage to the stator of a rotating electric machine for vehicle propulsion.

[0006] As a result, multiple DC / AC converters need to be placed onboard the vehicle, which results in clutter, extra cost, and added weight to the vehicle. Summary of the invention

[0007] There is a need to overcome all or some of the above disadvantages.

[0008] According to one of its aspects, the present invention satisfies this requirement using an electrical circuit comprising:

[0009] Inductive unit for contactless energy exchange,

[0010] Electrical energy storage unit,

[0011] an inverter / rectifier connected to the electrical energy storage unit and connectable to a phase of a stator of a propulsion rotary electric machine of the vehicle, the inverter / rectifier comprising a first switching arm and a second switching arm,

[0012] in,

[0013] A first terminal of the inductor unit is connected to a first switching arm of the inverter / rectifier,

[0014] A second terminal of the inductive unit is connected to a second switching leg of the inverter / rectifier.

[0015] The terminals of the inductive unit may or may not be connected to the switching arm by physical components inserted in series (eg via an inductor or a capacitor).

[0016] By connecting the terminals of the inductive unit to the switching arms of an inverter / rectifier connected to the phases of the rotating electrical machine, the invention as defined above allows the inverter / rectifier to be used not only in the case of propelling the vehicle in order to supply AC voltage to the stator of the rotating electrical machine providing all or part of the vehicle propulsion, but also in the case of charging the electrical energy storage unit in order to rectify the induced AC voltage, thus solving the above-mentioned weight, clutter and cost problems.

[0017] For example a three phase inverter / rectifier can then be arranged as:

[0018] In a first power path between the inductor unit and the electrical energy storage unit, and

[0019] In a second power path between the electrical energy storage unit and the stator of the rotating electrical machine.

[0020] Since charging the electrical energy storage unit is not performed simultaneously with propelling the vehicle, the two power paths are not activated at the same time.

[0021] Inverters / rectifiers may include:

[0022] a first switch arm, the first switch arm comprising two controllable electronic switches connected in series on both sides of a first midpoint,

[0023] a second switch arm, the second switch arm comprising two controllable electronic switches connected in series on both sides of the second midpoint,

[0024] a third switch arm, the third switch arm comprising two controllable electronic switches connected in series on both sides of the third midpoint,

[0025] The first switch arm, the second switch arm and the third switch arm are connected in parallel,

[0026] The inverter / rectifier can be connected to a three-phase stator of a rotating electrical machine, and the first midpoint, the second midpoint and the third midpoint can be connected to different phases of the stator, respectively.

[0027] A first terminal of the inductor unit is connected to the first midpoint, and

[0028] The second terminal of the inductor unit is connected to the second midpoint.

[0029] In this case, the phases of the stator are star-connected or delta-connected.

[0030] The switching frequencies of the first switching arm, the second switching arm, and the third switching arm may be different.

[0031] The inverter / rectifier is configured to perform impedance matching by changing the equivalent impedance between the first midpoint and the second midpoint independently of the equivalent impedance of the load represented by the electrical energy storage unit. The impedance matching achieved by the inverter / rectifier is described, for example, in the application WO2024068486 of the present applicant. The content of the application on how to control the two switch arms to which the inductive unit is connected to the midpoint to achieve impedance matching is incorporated herein by reference.

[0032] In this case, one of the first switching arm and the second switching arm can be switched at the frequency of the contactless energy exchange, and the other of the first switching arm and the second switching arm can be switched at a higher frequency (for example, 5 times or 10 times the frequency equal to or greater than the frequency of the contactless energy exchange).

[0033] More precisely, one of the switching arms can be switched at the frequency of the contactless energy exchange and with a duty cycle of 50%, and the other arm can be switched at a higher frequency (for example equal to or greater than 5 or 10 times the frequency of the contactless energy exchange) and with a duty cycle modulated according to the AC current flowing through the inductive unit and the voltage on the AC interface of the inverter / rectifier.

[0034] The inverter / rectifier is, for example, configured such that its three switching arms switch at the same frequency during propulsion of the vehicle.

[0035] At least one of the terminals of the inductive unit may be connected to a switching arm of the inverter / rectifier via a switch. The switch may, for example, comprise a transistor.

[0036] Advantageously, the presence of the switch allows the electrical energy storage unit to be isolated from the inverter / rectifier when the inverter / rectifier supplies power to the stator of the rotating electrical machine. This therefore increases the safety of the circuit.

[0037] Each terminal of the inductive unit is connected to a switching arm of the inverter / rectifier, for example via a switch.

[0038] The electrical circuit may comprise at least one switch by which a switching arm of the inverter can be connected to a phase of the stator of the rotating electrical machine.

[0039] For example, for each switching arm to which a terminal of the inductive unit is connected, the circuit comprises a switch by which this switching arm of the inverter / rectifier can be connected to a phase of the stator of the rotating electrical machine. This variant is another way to isolate the electrical energy storage unit from the stator of the rotating electrical machine and thus improve the safety of the circuit.

[0040] If desired, a DC / DC converter may be connected in series between the energy storage unit and the inverter / rectifier.

[0041] The electrical energy storage unit may have a voltage greater than or equal to 60 volts. The electrical energy storage unit may typically be a lithium-ion battery. The battery may have, for example, a nominal voltage of 12V, 48V, 60V or more, such as greater than 300V, such as 400V, 800V or 1000V.

[0042] The contactless exchange of electrical energy by inductive coupling takes place, for example, at a frequency below 10 kHz, in particular below 7 kHz, in particular below 5 kHz, for example below 3 kHz, or even below 2 kHz or 1 kHz, in particular substantially equal to 400 Hz or 50 Hz.

[0043] As already mentioned, the inverter / rectifier can allow impedance matching to be performed when charging the energy storage unit, by:

[0044] controlling the first switching arm to switch at a contactless energy transfer frequency, and

[0045] The second switching arm is controlled to switch at a frequency equal to a multiple of the contactless energy transfer frequency.

[0046] The present invention also relates to a power supply circuit for an electric energy storage unit, the power supply circuit comprising:

[0047] a first circuit, which is referred to as the "primary circuit", and

[0048] a second circuit, called the "secondary circuit", corresponding to the circuit defined above,

[0049] The primary circuit is connectable to a voltage network and comprises:

[0050] a primary inverter / rectifier which can be connected to a voltage network via another primary inverter / rectifier as required, and

[0051] Primary inductor unit for contactless energy exchange,

[0052] The primary circuit and the secondary circuit are configured to contactlessly exchange energy via the inductive unit.

[0053] The primary circuit and the secondary circuit may each include a control unit configured to control a switching frequency of the switching arm.

[0054] As a variant, only one control unit (eg a digital processing circuit) may be provided, which controls the switching arms of the primary circuit and the secondary circuit.

[0055] As another variation, the control unit is common to the primary circuit and the secondary circuit and the control unit comprises a primary circuit control module and a secondary circuit control module.

[0056] The primary circuit may include a capacitor having a first terminal connected to a terminal of the inductive unit and a second terminal connected to the primary inverter / rectifier.

[0057] The electrical network provides a nominal RMS voltage of, for example, 230 V or 110 V, with a frequency of 50 Hz or 60 Hz. The electrical network is, for example, single-phase.

[0058] The electrical network is for example a regional or national electrical network.As a variant, the electrical network may be an independent local network comprising one or more batteries powered for example by an energy source such as a wind turbine, solar panels, fuel cells or hydro generators.

[0059] To allow contactless exchange of power between the primary circuit and the secondary circuit, the inductive unit of the primary circuit and the inductive unit of the secondary circuit are configured to contactlessly exchange power through inductive coupling.

[0060] The primary inductance unit may include a coil allowing magnetic energy to be generated, and the secondary inductance unit may include a coil allowing magnetic energy from the primary inductance unit to be recovered.

[0061] As already mentioned, contactless electrical energy exchange by inductive coupling can be carried out at a frequency below 10 kHz, in particular below 7 kHz, in particular below 5 kHz, for example below 3 kHz, or below 2 kHz or 1 kHz, in particular substantially equal to 400 Hz or 50 Hz.

[0062] The primary inductance unit and the secondary inductance unit may have the same resonant frequency, and contactless power exchange by inductive coupling may occur at the resonant frequency.

[0063] In all of the above, the control unit may be configured to control different switch arms to selectively:

[0064] charging an energy storage unit from a voltage network, or

[0065] The voltage network is charged from the electrical energy storage unit.

[0066] Thus, electrical energy can be exchanged in one direction or the other as required.

[0067] In all the above, each controllable electronic switch is, for example, a transistor (eg, a bipolar, MOS or IGBT transistor) or a thyristor. Each controllable electronic switch is, for example, bidirectional.

[0068] In all of the above, each control unit may be a digital processing circuit, such as an ASIC (Application Specific Integrated Circuit) or a microcontroller.

[0069] According to another of its aspects, another subject of the invention is an electrical circuit intended to be placed on-board a vehicle, the electrical circuit comprising:

[0070] Inductive unit for contactless energy exchange,

[0071] Electrical energy storage unit,

[0072] Propulsion of rotating electrical machines, and

[0073] A single inverter / rectifier comprising at least two switching arms, each of which is connected to an inductive unit and to at least one phase of a stator of a rotating electrical machine, to alternately allow charging of an electrical energy storage unit by rectifying a voltage induced at the terminals of the inductive unit, and supply of power to the stator of the rotating electrical machine.

[0074] All that is described above also applies to this other aspect of the invention.

[0075] For example, the switching arm is connected to a phase of the stator and to the inductive unit via a midpoint of the switching arm.

[0076] At least one switch may be present between a switching arm and the inductive unit or between a switching arm and a phase of the stator.

[0077] Such a circuit may constitute a secondary circuit in a similar manner to that already described above and may be combined with the primary circuit described above.

[0078] In a similar manner to that already mentioned, a single inverter / rectifier may allow impedance matching to be performed when charging an electrical energy storage unit, as described above.

[0079] According to another aspect of the invention, another subject of the invention is a component for supplying power to an electrical energy storage unit, the component comprising an electrical circuit according to any one of the above aspects, the component particularly defining a structure supporting the primary circuit and the secondary circuit so that they are rigidly coupled to each other. Such a component is generally referred to as an "on-board charger". Such a component can be placed on-board a hybrid or electric vehicle.

[0080] According to another aspect of the invention, another subject of the invention is a device for supplying power to an electrical energy storage unit, comprising:

[0081] A charging station for a hybrid or electric vehicle, in which a primary circuit of an electrical circuit as defined above is arranged or connected to the charging station, and

[0082] A component capable of being placed onboard a hybrid or electric vehicle, in which component a secondary circuit of an electrical circuit as defined above is arranged.

[0083] The terminal then receives electrical energy from the electrical network via a cable, which may be a single-phase cable or a three-phase cable. In this case, the primary circuit and the secondary circuit are not integrated in the same physical component.

[0084] The vehicle to which the electrical energy storage unit belongs is, for example, an electric or hybrid vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] The invention will be better understood by reading the following description of non-limiting exemplary embodiments of the invention and by studying the accompanying drawings, in which:

[0086] Figure 1 schematically shows a part of a power supply circuit for an electrical energy storage unit according to a first exemplary embodiment of the invention, and

[0087] Figure 2 The power supply circuit is schematically shown, including Figure 1 The content shown. DETAILED DESCRIPTION

[0088] Figure 1 A circuit 60 is shown, comprising:

[0089] An inductor unit 16, which is used for contactless energy exchange,

[0090] The electrical energy storage unit 20,

[0091] An inverter / rectifier 7 connected to the electrical energy storage unit 20 and to the phases of the stator of a propulsion rotary electric machine 8 (eg, of an electric vehicle).

[0092] A first terminal of the inductor unit 16 is connected to a first switching leg of the inverter / rectifier 7 .

[0093] A second terminal of the inductor unit 16 is connected to a second switching leg of the inverter / rectifier 7 .

[0094] In the described example, a primary impedance having a value Zp is connected in series with the primary inductance unit 16 between the first switching leg and the second switching leg of the inverter / rectifier 7. The primary impedance having a value Zp comprises an inductor 18 and a capacitor 24 connected in series.

[0095] Figure 1 The circuit 60 (also referred to as “secondary circuit”) is integrated in the power supply circuit of the electrical energy storage unit 20 .

[0096] like Figure 2 As shown, the secondary circuit 60 may be configured to contactlessly exchange energy with the primary circuit 40 .

[0097] like Figure 2 As shown, the primary circuit 40 is connected to the voltage network 2 and comprises:

[0098] A first primary inverter / rectifier 44 and a second primary inverter / rectifier 46 connected in series, the first primary inverter / rectifier 44 being connected to the voltage network 2,

[0099] a primary inductor unit 48 for contactless energy exchange, and

[0100] Capacitor 42.

[0101] The capacitor 42 is connected to a first terminal of the primary inductor unit 48 and to the second primary inverter / rectifier 46. The second terminal of the primary inductor unit 48 is connected to the second primary inverter / rectifier 46.

[0102] As already mentioned, the secondary circuit 60 comprises a secondary inductive unit 16 for contactless energy exchange, an energy storage unit 20 , and a secondary inverter / rectifier 7 connected to the energy storage unit 20 and to the phases of the stator of the rotating electrical machine 8 .

[0103] The primary circuit and the secondary circuit are configured to contactlessly exchange energy via the inductive unit.

[0104] The power supply circuit implements contactless power exchange through inductive coupling between the primary circuit 40 and the secondary circuit 60 , so as to charge the power storage unit 20 .

[0105] In the example considered, there is only a single secondary voltage inverter / rectifier 7 and this secondary voltage inverter / rectifier comprises:

[0106] A first switch arm B1, which includes two controllable electronic switches 12 connected in series on both sides of a first midpoint,

[0107] A second switch arm B2, comprising two controllable electronic switches 12 connected in series on both sides of the second midpoint, and

[0108] The third switch arm B3 includes two controllable electronic switches 12 connected in series on both sides of the third midpoint.

[0109] Each controllable electronic switch comprises, for example, a MOS, an IGBT, or a bipolar transistor, or a thyristor.

[0110] The first switching arm B1 , the second switching arm B2 , and the third switching arm B3 are connected in parallel, and the first midpoint, the second midpoint, and the third midpoint are respectively connected to different phases of the stator of the rotary electric machine 8 .

[0111] A first terminal of the secondary inductor unit 16 is connected to the first midpoint, and a second terminal of the secondary inductor unit 16 is connected to the second midpoint.

[0112] The primary inductance unit 16 comprises, for example, a coil allowing the generation of magnetic energy, and the secondary inductance unit 48 comprises, for example, a coil allowing the recovery of magnetic energy from the primary inductance unit by magnetic coupling.

[0113] The voltage network 2 provides a nominal RMS voltage of, for example, 230 V or 110 V, with a frequency of 50 Hz or 60 Hz. In this case, the voltage network 2 is single-phase, so that the voltage at the terminals of the secondary voltage inverter / rectifier 7 is also single-phase.

[0114] In the example considered, the switching frequencies of the first switching arm B1, the second switching arm B2 and the third switching arm B3 may be different when charging the electric energy storage unit 20. The switching frequency of one of the switching arm B1 and the switching arm B2 for the secondary circuit 60 is, for example, greater than the power transmission frequency (for example, at least 5 times the power transmission frequency), while the other of the switching arm B1 and the switching arm B2 is switched at the power transmission frequency.

[0115] The electrical energy storage unit is connected to the secondary inverter / rectifier 7 , for example via a DC / DC converter 22 .

[0116] The DC / DC converter 22 is connected in parallel to the three arms B1 , B2 , and B3 , for example.

[0117] The present invention has been described above using the embodiments shown in the drawings, but without limiting the general inventive concept.

[0118] Numerous other modifications and variations will be apparent to those skilled in the art after considering the various embodiments presented in this application.

[0119] These embodiments are given by way of example and are not intended to limit the scope of the present invention, which is determined solely by the following claims.

[0120] In the claims, the word "comprising" does not exclude other elements or steps.

[0121] The mere fact that various features are recited in mutually dependent claims does not indicate that a combination of features can be used to advantage. Finally, any references used in the claims shall not be construed as limiting the scope of the invention.

Claims

1. A circuit, include: An inductive unit (16) for contactless energy exchange, an electrical energy storage unit (20), an inverter / rectifier (7) connected to the electrical energy storage unit (20) and connectable to a phase of a stator of a rotating electrical machine (8), the inverter / rectifier (7) comprising a first switching arm (B1) and a second switching arm (B2), in, A first terminal of the inductor unit (16) is connected to a first switching arm of the inverter / rectifier (7), and a second terminal of the inductor unit (16) is connected to a second switching arm of the inverter / rectifier (7).

2. The circuit according to claim 1, in, The inverter / rectifier (7) comprises: A first switch arm (B1) comprises two controllable electronic switches (12) connected in series on either side of a first midpoint, A second switch arm (B2) comprises two controllable electronic switches (12) connected in series on either side of the second midpoint, A third switch arm (B3) comprises two controllable electronic switches (12) connected in series on either side of the third midpoint, The first switch arm (B1), the second switch arm (B2) and the third switch arm (B3) are connected in parallel, the inverter / rectifier (7) can be connected to a three-phase stator of the rotating electrical machine (8), the first midpoint, the second midpoint and the third midpoint can be connected to different phases of the stator respectively, A first terminal of the inductor unit (16) is connected to the first midpoint, and a second terminal of the inductor unit (16) is connected to the second midpoint.

3. The circuit according to claim 2, wherein the inverter / rectifier (7) is configured to perform impedance matching by changing the equivalent impedance between the first midpoint and the second midpoint independently of the equivalent impedance of the load represented by the electrical energy storage unit.

4. The circuit according to claim 3, one of the first switching arm and the second switching arm is switched at the frequency of the contactless energy exchange and with a duty cycle of 50%, and the other of the first switching arm and the second switching arm is switched at a higher frequency, in particular, at a frequency equal to or greater than 5 times or 10 times the frequency of the contactless energy exchange, and at a duty cycle modulated according to the AC current flowing through the inductive unit and the voltage on the AC interface of the inverter / rectifier.

5. A circuit according to any one of the preceding claims, in, At least one terminal of the inductor unit (16) is connected to a switching arm of the inverter / rectifier (7) via a switch (80).

6. Circuit according to any of the preceding claims, comprising a switch (84) by means of which at least one switching arm of the inverter can be connected to at least one phase of the stator of the rotating electrical machine (8).

7. A circuit according to any one of the preceding claims, in, The electrical energy storage unit (20) is connected to the inverter / rectifier (7) via a DC / DC converter (22).

8. A power supply circuit for an electric energy storage unit (20), the power supply circuit include: a first circuit (40), referred to as a "primary circuit", and A second circuit (60) according to any of the preceding claims, the second circuit being referred to as a "secondary circuit", The primary circuit (40) is connectable to a voltage network (2) and comprises: a primary inverter / rectifier (44) which can be connected to the voltage network (2) via a further primary inverter / rectifier (46) as required, and a primary inductor unit (48) for the contactless energy exchange, The primary circuit and the secondary circuit are configured to contactlessly exchange energy via the inductive unit.

9. The power supply circuit according to claim 8, in, The primary circuit and the secondary circuit are configured such that a frequency for transferring power by induction is less than or equal to 10 kHz, in particular less than 7 kHz, in particular less than 5 kHz.

10. The power supply circuit according to claim 9, in, The primary inductance unit and the secondary inductance unit have the same resonant frequency, and the contactless power exchange by inductive coupling occurs at the resonant frequency.

11. An electrical circuit (60) intended to be placed on-board a vehicle, include: an inductive unit (16) for the contactless energy exchange, an electrical energy storage unit (20), a propulsion rotary motor (8), and A single inverter / rectifier (7) comprising at least two switching arms (B1, B2, B3), each of the at least two switching arms being connected to the inductor unit (16) and to at least one phase of the stator of the rotating electrical machine to alternately allow: charging the electrical energy storage unit (20) by rectifying the voltage induced at the terminals of the inductor unit (16), and supplying power to the stator of the rotating electrical machine (8).

12. A device for supplying power to an electrical energy storage unit, include: Charging station for hybrid or electric vehicles, in which a circuit called "primary circuit" which can be connected to a voltage network (2) is arranged or connected to the charging station, the circuit comprising: a primary inverter / rectifier (44) which is connectable to the voltage network (2), a primary inductor unit (48) for contactless energy exchange, and A component which can be placed on-board a hybrid vehicle or an electric vehicle, in which a circuit referred to as a "secondary circuit" according to any one of claims 1 to 7 or according to claim 11 is arranged, The primary circuit and the secondary circuit are configured to contactlessly exchange energy via the inductive unit.

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