EP3747106A1

EP3747106A1 - Device for transmitting power contactlessly through resonant inductive coupling for recharging a motor vehicle

Info

Publication number: EP3747106A1
Application number: EP19701386.5A
Authority: EP
Inventors: Nicolas Labbe
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2018-01-31
Filing date: 2019-01-30
Publication date: 2020-12-09
Also published as: FR3077439B1; WO2019149726A1; FR3077439A1; CN112005463A

Abstract

Device (100) for transmitting power contactlessly through resonant inductive coupling, in particular for the purpose of charging or recharging a motor vehicle with electricity, including: - a power source (10), in particular an AC power source; - a transmitter resonant circuit (1) comprising a first capacitor (C1) and a first winding (E1), the first winding (E1) including an inductor and a first resistor, the transmitter resonant circuit being supplied with power by the power source (10); - a receiver resonant circuit (2) including a second capacitor (C2) and a second winding (E2), the second winding (E2) including a second inductor and a second resistor, characterized in that the inductance value of the second inductor varies in a predetermined manner.

Description

CONTACTLESS POWER TRANSMISSION DEVICE BY INDUCTIVE RESONANCE COUPLING FOR RECHARGING A MOTOR VEHICLE

The present invention provides a receiver resonant circuit and a resonance inductive coupling non-contact power transmission device for charging or recharging a motor vehicle.

In a manner known per se, it is technically possible to supply by non-contact transmission a motor vehicle or any other object provided with a device for storing electrical energy at a power of between 3 and 10 kW, when this object is at the shutdown (in this case of static load), or when it moves (it is called dynamic load.This power transmission by contactless transmission is then by means of magnetically coupled remote electrical circuits and granted to the The magnetically coupled circuits each comprise at least one resonant LC element, L and C respectively denoting inductances and capacitances.

The problem with this type of solution is that in order to transmit a satisfactory power level, especially several kW, it is necessary to operate at high frequencies, in particular of the order of 85 kHz or more, for the working frequency and for the natural frequency. of each resonant circuit. In addition, this type of solution requires operating at a short distance between the resonant elements located at the source and the load.

To operate at such a high level of frequency mainly results in the necessity of using expensive components such as soft ferrites and Litz conductive wire whose strands are of very small cross-section, for example less than or equal to 0.07 mm. diameter.

The invention aims to overcome, at least in part, these disadvantages.

For this purpose, the subject of the invention is a resonant receiver circuit for producing contactless power transmission by inductive coupling with resonance with an emitter resonant circuit having a first capacitance and a first winding, the first winding having an inductance and a first resistor,

the resonant receiver circuit comprising a second capacitance of value C2 'and a second winding, the second winding having a second inductance of value L2', a second resistance of value R2 ',

the receiver resonant circuit having an own pulse w2 such that w2 = 1L / (I_2 'x C2') and an eigenfrequency f2 such that f2 = w2 / (2tt), characterized in that the inductance value of the second inductor (L2) varies in a predetermined manner.

The invention makes it possible to increase the amplitude of a starting electric current supplied by the emitting resonant circuit to the resonant receiving circuit, when the emitter resonant circuit is magnetically coupled to the resonant receiver circuit.

According to one implementation, the second inductor comprises a magnetic circuit.

According to one implementation, the inductance value of the second inductance varies by varying the reluctance of the magnetic circuit of the second inductor.

According to one embodiment, the magnetic circuit of the second inductor comprises at least one movable portion relative to the second winding.

According to one embodiment, the magnetic circuit of the second inductor comprises at least one fixed part, relative to the second winding.

According to one embodiment, the fixed part and the mobile part comprise a ferromagnetic or ferrimagnetic material.

According to one embodiment, the moving part is set in motion so that projections are alternately facing other projections or between two projections. According to one implementation, the moving part of the magnetic circuit of the second inductor is driven by an electric motor.

According to one implementation, the second inductor is made in one piece.

According to one implementation, the second inductor comprises a solenoid, in particular of substantially flattened shape.

According to one implementation, the inductance value of the second inductance varies according to a predetermined frequency and according to a predetermined amplitude of inductance variation hL around a mean value L2moy, so that the own pulse varies according to an amplitude of predetermined hto pulse variation around a mean value 2moy, with to2moy = 1 / V (L2moy x C2 ').

The invention thus makes it possible to amplify the amplitude of the current and of the voltage, at the level of the resonant receiver circuit, with an amplification gain sufficiently high to allow operation at a lower frequency, and / or a higher distance.

According to one implementation, the predetermined frequency is chosen so as to increase the amplitude of the electric current flowing in the exponential growth resonant circuit.

The invention thus makes it possible, by introducing an amplification gain, to transmit a satisfactory level of power by a non-contact method between an emitter resonant circuit and a resonant receiver circuit, despite the implementation of a frequency very low level compared to the state of the art.

According to one implementation, the second capacitance has a substantially constant value.

According to one embodiment, the receiver resonant circuit is arranged to be tuned to the emitter resonant circuit. As a result, the receiver resonant circuit and the emitter resonant circuit have substantially the same natural frequency. According to one implementation, the predetermined frequency is equal to twice the natural frequency of the resonant receiver circuit to a tolerance.

Such a predetermined frequency makes it possible to increase the amplitude of the electric current flowing in the resonant receiver circuit. According to one implementation, the tolerance e is such that e = V (((1/2) x hL x üj2moy) ² - (R27 L2 ') ² ).

Thus, the predetermined frequency is between (2xf2) - e and (2xf2) + e.

According to one implementation, the predetermined pulse variation amplitude hoo is strictly greater than 2 x (R2 '/ L2') x V (L2 'x C2'). According to one implementation, the second inductor is formed by a variable magnetic reluctance assembly comprising a rotor and a stator with the presence of an air gap between them,

- the stator (3) comprising a solenoid (5) and a plurality of stator arms (4), the set of stator arms (4) forming a single magnetic pole when the solenoid (5) is traversed by an electric current and the pole being notably considered on the side of the gap,

- The rotor (6) having a plurality of rotor arms (7) forming a single magnetic pole when the solenoid (5) is traversed by an electric current and the pole being particularly considered on the side of the air gap. According to one implementation, two adjacent rotor arms are separated in pairs by a non-magnetic portion.

According to one embodiment, two adjacent stator arms are separated two by two by a non-magnetic portion.

According to one implementation, the number of stator arms is equal to the number of rotor arms.

As a variant, the number of stator arms is different from the number of rotor arms

According to one implementation, each stator arm extends in a radial direction relative to the axis of rotation of the rotor and comprises a package of plates magnetic laminated whose stack is in particular made in a direction orthoradiale relative to the radial direction in which the stator arm extends.

According to one implementation, the stack is made in a direction orthoradial with respect to the axis of rotation of the rotor.

In a variant, the stack is made in a direction parallel to the axis of rotation of the rotor.

According to one embodiment, each rotor arm extends in a radial direction relative to the axis of rotation of the rotor and comprises a laminated sheet of magnetic laminations whose stack is in particular made in a direction orthoradial with respect to the direction radial in which extends the rotor arm.

According to one implementation, the stack is made in a direction orthoradial with respect to the axis of rotation of the rotor. In a variant, the stack is made in a direction parallel to the axis of rotation of the rotor.

According to one embodiment, the rotor comprises a non-magnetic shaft.

This allows the flow to pass only through the rotor arms and not through the shaft, in an axial direction. According to one embodiment, each rotor arm comprises a projecting portion, in particular arranged radially on the side of the axis of rotation of the rotor.

This allows a good maintenance of the rotor arms on the shaft and limits the flow of leakage by channeling the magnetic flux from an external magnetic source. According to one embodiment, the solenoid comprises a flat coil, or a plurality of coils extending concentrically and / or extending axially, the turns being in particular without Litz wire. According to one embodiment, the solenoid is arranged so that an alternating current flowing in the turns is strictly less than 3 kHz.

According to one implementation, the turns comprise Litz wire whose section has a diameter strictly greater than 0.2 mm, in particular strictly greater than 0.3 mm.

This reduces the number of wires and thus greatly simplify the implementation of the solenoid.

According to one embodiment, the rotor is coupled to a motor to enable it to be rotated, in particular at a predetermined speed W, this speed being expressed in revolutions / s and being such that W = ((2 x f2) + e) / (N), where N is the number of stator arms.

According to one embodiment, the second capacitance comprises a polypropylene capacitor, in particular of at least 900 pF.

The invention also relates to a contactless power transmission device by inductive resonance coupling, in particular for charging or recharging an electric vehicle, comprising:

a source of energy, in particular with alternating current,

an emitter resonant circuit comprising a first capacitance and a first winding, the first winding comprising an inductance and a first resistor, the emitter resonant circuit being fed by the energy source,

a resonant receiver circuit as described above.

The invention further relates to a charging or charging unit without contact of a motor vehicle, comprising:

a resonance inductive coupling non-contact power transmission device as described previously,

a rectifier, electrically connected to the receiver resonant circuit, for rectifying an electric current generated by the variation of the magnetic field originating from the emitter resonant circuit,

- An electrical energy storage device, loaded by the rectifier. The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given for illustrative but not limiting of the invention.

FIG. 1 is a schematic representation of a non-contact charging or recharging assembly of a motor vehicle according to the invention;

FIG. 2 is a diagrammatic representation of a non-contact inductive resonance coupling power transmission device according to the invention;

Figure 3 is a schematic representation of a variable magnetic reluctance assembly according to the invention; and

Figure 4 is a schematic representation of the assembly of Figure 3, in section A-A.

As can be seen in FIG. 1, a motor vehicle 30 carries an electrical energy storage device 20, in particular a battery 20 for supplying electrical energy to an electric traction motor (not shown) and the vehicle's electrical system. The battery 20 of the motor vehicle 30 has, for example, a nominal voltage of 48V or 300V and can be charged or recharged without contact by means of a non-contact resonance coupling power transmission device 100.

In the example of FIG. 1, the non-contact resonance-inductive coupling power transmission device 100 comprises an AC power source 10 supplying a rectifier 12, the rectifier 12 being electrically connected to an inverter 13 which supplies power to the rectifier 12. thus a transmitter resonant circuit 1 AC at a frequency greater than that of the source 10. Alternatively, the power source 10 could be at a frequency usable directly without the need to use a rectifier 12 and an inverter 13 In the example of FIG. 1, the winding E0 is fed via the wire connection to the energy source 10. This winding E0 then feeds the emitter resonant circuit 1 by inductive coupling. In a variant that is not shown, the AC power source 10 could directly supply the emitter resonant circuit 1 with alternating current.

In the example of FIG. 1, the emitter resonant circuit 1 comprises a first capacitance C1 and a first winding E1.

The resonance inductive coupling non-contact power transmission device 100 further comprises a receiver resonant circuit 2 having a second capacitance C2 and a second winding E2.

When the emitter resonant circuit 1 is magnetically coupled to the resonant receiver circuit 2, there is non-contact resonant resonance-coupled power transmission to the resonant receiver circuit 2. This magnetic coupling occurs when the first E1 and second E2 windings are in close proximity. one of the other. In the example considered, this coupling takes place when the first E1 and second E2 windings are substantially at a distance of between 10 cm and 1 m. In another example, the coupling takes place, even if the performance is degraded, when the distance is between 1 m and 10 m.

As can be seen in FIG. 2, the energy source 10 is connected to a resistor R0 in series with a transmission coil L0. The winding E0 shown in FIG. 1 indeed has the parasitic resistance R0 in series with a transmission coil L0. In Figure 2, the rectifier 12 and the inverter 13 have not been shown for simplicity.

As can be seen in FIG. 2, the emitter resonant circuit 1 consists of an RLC circuit. Indeed, the emitter resonant circuit 1 comprises a first inductor L1 in series with a first resistor R1 and a first capacitance C1. The first winding E1 shown in FIG. 1 indeed has the parasitic resistance R1 in series with the first inductance L1.

The emission coil L0 is magnetically coupled to the first inductor L1. The resonant receiver circuit 2 consists of an RLC circuit. Indeed, the resonant receiver circuit 2 comprises a second inductor L2 in series with a second resistor R2 and a second capacitance C2. The second winding E2 shown in FIG. 1 indeed has the parasitic resistance R2 in series with the first inductance L2.

The second capacitance C2 comprises a polypropylene capacitor of at least 900 pF.

In the example shown, the emitter resonant circuit 1 and the resonant receiver circuit 2 are tuned. The receiver resonant circuit and the emitter resonant circuit thus have substantially the same natural frequency.

As can be seen in FIG. 2, a reception coil L3 is electrically connected to a resistor R3 schematically representing a parasitic resistance in series with the load constituted by the rectifier 11 and the battery 20 of FIG.

The winding E3 shown in FIG. 1 here comprises the parasitic resistance in series with the reception coil L3.

The receiving coil L3 is magnetically coupled to the second inductor L2.

In the example of FIGS. 1 and 2, the emitter resonant circuit 1 and the emission coil L0 are located on the ground, while the resonant receiver circuit 2 and the reception coil L3 are located on board the vehicle.

In the example of FIGS. 1 and 2, the second capacitance has a value C2 ', the second inductance has a value L2', and the second resistance has a value R2 '. In addition, the receiver resonant circuit 1 has for its own pulsation w2 such that QJ2 = 1 / V (L2 'X C2') and for natural frequency f2 such that f2 = w2 / (2tt).

The inductance value of the second inductance L2 varies in a predetermined manner.

More specifically, the inductance value of the second inductor L2 varies according to a predetermined frequency and according to a variation amplitude inductance hl_ predetermined around a mean value L2moy, so that the own pulse varies with a predetermined hto pulse variation amplitude around a mean value Qj2moy, with to2moy = 1 / V (L2moy x C2 ').

The predetermined frequency being chosen so as to increase the amplitude of the alternating electric current flowing in the exponential growth resonant circuit 2.

The second capacitance C2 has a substantially constant value. By substantially constant value is meant the value of this capacitance, not including variations thereof due to temperature or wear or any other physical factor.

The predetermined frequency is equal to twice the natural frequency of the resonant circuit receiver to a tolerance e near. This tolerance is such that

Thus, the predetermined frequency is between (2xf2) - e and (2xf2) + e.

Such a predetermined frequency makes it possible to increase the amplitude of the electric current flowing in the resonant receiver circuit.

According to one embodiment, the predetermined pulse variation amplitude hoo is strictly greater than 2 x (R2 '/ L2') x V (L2 'x C2').

An embodiment of the second inductor L2 is described with reference to FIGS. 3 and 4.

The second inductor L2 is here formed by a variable magnetic reluctance assembly comprising a rotor 6 and a stator 3 with the presence of an air gap between them. The stator 3 comprises a solenoid 5 and a plurality of stator arms 4, the set of stator arms 4 forming a single magnetic pole when the solenoid 5 is traversed by an electric current. The pole is considered here on the side of the gap. The rotor 6 comprises a plurality of rotor arms 7 forming a single magnetic pole when the solenoid 5 is traversed by an electric current. The pole is considered here on the side of the gap. Thus, the solenoid 5 constitutes a winding. The stator constitutes a fixed part and the rotor constitutes a movable part, relatively to the winding.

As can be seen in FIG. 3, two adjacent rotor arms 7 are separated in pairs by a non-magnetic portion and two adjacent stator arms 4 are separated in pairs by a non-magnetic portion. In the example considered, the number of stator arms 4 is equal to the number of rotor arms 7, in this case, this number is equal to 12.

Thus, the stator 3 has a plurality of projections, all the same polarity, this polarity in the direction of the north or south orientation, being a function of the phase of the current flowing through the solenoid 5. In addition, the rotor 6 has a plurality of protrusions, all the same polarity, this polarity in the direction of the north or south orientation, being a function of the phase of the current flowing through the solenoid 5. The stator 3 and the rotor 6 each have the same number of magnetic projections, separated by absence of magnetic matter. Each stator arm 4 extends in a radial direction relative to the axis of rotation X of the rotor and comprises a laminated sheet of magnetic sheets whose stacking is carried out in a direction orthoradial with respect to the radial direction in which s' extends the stator arm 4. In the example considered, the stack is made in a direction orthoradial with respect to the axis of rotation X of the rotor 6.

Each rotor arm 7 extends in a radial direction with respect to the axis of rotation X of the rotor and comprises a laminated sheet of magnetic sheets whose stacking is carried out in a direction orthoradial with respect to the radial direction in which s' extends the rotor arm 7. In the example considered, the stack is made in a direction orthoradial with respect to the axis of rotation X of the rotor.

The rotor 6 comprises a shaft 8 which is made of a non-magnetic material. This allows the flow to pass only through the rotor arms 7 and not the shaft 8, in an axial direction. In the example considered, the nonmagnetic shaft 8 of the rotor 6 is neither laminated nor made of soft ferrite in order to avoid the formation of harmful induced currents in said shaft 8.

As can be seen in FIG. 4, each rotor arm 7 comprises a protruding portion, in particular disposed radially on the side of the axis of rotation X of the rotor 6. This makes it possible to channel the magnetic flux while allowing better mechanical support. of the assembly constituting the rotor 6.

In the example of Figure 3, the solenoid 5 has a plurality of coils extending concentrically. In the example of Figure 4, the solenoid 5 may include a plurality of axially extending turns. Alternatively not shown, the solenoid 5 may comprise a single turn flat.

The turns are devoid of Litz wire. As a variant, the turns comprise Litz wire whose section has a diameter strictly greater than 0.2 mm, in particular strictly greater than 0.3 mm.

The solenoid 5 is arranged such that an alternating current flowing in the turns constituting it, with a frequency strictly less than 3 kHz.

An electric motor (not shown) is coupled to the shaft 8 to enable the rotor 6 to be rotated at a predetermined speed W expressed in revolutions / s and being such that W = ((2xfo) +/- e) / (N ), N being the number of stator arms 4. This predetermined speed is considered steady state, that is to say at the end of an electro-mechanical transient regime.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention which would not be overcome by replacing the different elements by any other equivalent.

In addition, the various features, variations, and / or embodiments of the present invention may be associated with each other in various combinations, to the extent that they are not incompatible or exclusive of each other.

Claims

Receiver resonant circuit (2) for performing non-contact resonance-inductive coupling power transmission with an emitter resonant circuit (1) having a first capacitance (C1) and a first winding (E1), the first winding (E1) comprising an inductor (L1) and a first resistor (R1), the receiver resonant circuit (2) having a second capacitance (C2) of value C2 'and a second winding (E2), the second winding (E2) comprising a second inductor ( L2) of value L2 ', a second resistor (R2) of value R2', the receiver resonant circuit (2) having an own pulse w2 such that w2 = 1L / (I_2 'x C2') and an eigenfrequency f2 such that f2 = w2 / (2tt),

characterized in that the inductance value of the second inductor (L2) varies in a predetermined manner.

2 circuit (2) according to the preceding claim, the inductance value of the second inductor (L2) varying at a predetermined frequency and a predetermined inductance variation amplitude hL around a mean value L2moy, so that the eigenvalence varies according to a predetermined hto pulse variation amplitude around a mean value to2moy, with to2moy = 1 / V (L2moy x C2 ').

Circuit (2) according to the preceding claim, the predetermined frequency being chosen so as to increase the amplitude of the electric current flowing in the resonant circuit receiver (2), exponentially growing.

4. Circuit (2) according to any one of the preceding claims, the receiver resonant circuit (2) being arranged to be tuned to the emitter resonant circuit (1). Circuit (2) according to one of Claims 2 to 4, characterized in that the predetermined frequency is equal to two times the natural frequency of the resonant circuit receiver (2) to a tolerance e near.

6. Circuit (2) according to the preceding claim, the tolerance e being such that e = V (((1/2) x hL x to2moy) ² - (R27L2 ') ² ). A circuit (2) as claimed in any one of claims 2 to 6, wherein the predetermined pulse variation amplitude is strictly greater than 2 x (R2 '/ L2') x V (L2 'x C2').

8 (2) according to any one of the preceding claims, the second inductor (L2) being formed by a variable magnetic reluctance assembly comprising a rotor (6) and a stator (3) with the presence of an air gap between them,

- The rotor (6) having a plurality of rotor arms (7) forming a single magnetic pole when the solenoid (5) is traversed by an electric current and the pole being particularly considered on the side of the air gap. Circuit (2) according to the preceding claim, the number of stator arms (4) being equal to the number of rotor arms (7).

1 circuit (2) according to any one of claims 8 to 9, each stator arm (4) extending in a radial direction relative to the axis of rotation of the rotor and comprising a laminated sheet of magnetic laminations of which stacking is in particular carried out in a direction orthoradiale with respect to the radial direction in which the stator arm (4) extends.

1 circuit (2) according to any one of claims 8 to 10, each rotor arm (7) extending in a radial direction relative to the axis of rotation of the rotor and comprising a laminated sheet of magnetic laminations of which stacking is notably carried out in a direction orthoradial with respect to the radial direction in which the rotor arm (7) extends.

The circuit (2) according to any of claims 8 to 12, the solenoid (5) having a flat coil, or a plurality of concentrically extending and / or axially extending turns, the turns being notably deprived of wire Litz.

13. Circuit (2) according to one of claims 8 to 13, the rotor (6) being coupled to a motor to enable it to be rotated in particular at a predetermined speed W, this speed being expressed in revolutions / sec. and being such that W = ((2 x f2) ± e) / (N), where N is the number of stator arms.

14. Circuit (2) according to any one of the preceding claims, the second inductor (L2) comprising a magnetic circuit, said magnetic circuit comprising at least one movable part, relative to the second winding (E2), the moving part being in particular moved by an electric motor.

15. Device (100) for non-contact power transmission by resonance inductive coupling, particularly for charging or recharging an electric vehicle, comprising:

a source of energy (10), in particular with alternating current,

an emitter resonant circuit (1) comprising a first capacitance (C1) and a first winding (E1), the first winding (E1) comprising an inductance (L1) and a first resistor (R1), the emitter resonant circuit being powered by the energy source (10),

- A resonant receiver circuit (2) according to any one of the preceding claims.