Contactless power transmission device by resonant inductive coupling for charging or recharging a motor vehicle

Abstract

Title: Contactless power transmission device by resonant inductive coupling for charging or recharging a motor vehicle The invention relates to a contactless power transmission device (200) by resonant inductive coupling, in particular for charging or recharging a motor vehicle (30) with electrical energy, comprising: a resonant transmitter circuit (1) comprising: a first capacitance C1 of value C1', a first winding E1 comprising: a first inductance L1 of value L1' a first resistance R1 of value R1' a resonant receiver circuit (2) comprising: a second capacitance C2 of value C2', a second winding E2 comprising: a second inductance L2 of value L2' a second resistance R2 of value R2' the resonant transmitter circuit having a natural pulsation ω1 such that ω1=1 / √(L1' x C1') and a natural frequency f1 such that f1 = ω1 / (2π),and the receiver resonant circuit having a natural pulsation ω2 such that ω2 = 1 / √ (L2' x C2') and a natural frequency f2 such that f2 = ω2 / (2π), and such that ω1 = ω2, the power transmission device (200) being configured so that: the transmitter (1) and receiver (2) resonant circuits are in inductive coupling, the electromotive force induced by the transmitter circuit (1) in the receiver circuit (2) varies in a predetermined manner, the electromotive force induced by the receiver circuit (2) in the transmitter circuit (1) varies in a predetermined manner. Figure for the abstract: Fig. 1,

Description

Title of the invention: Contactless power transmission device by resonant inductive coupling for charging or recharging a motor vehicle

[0001] The present invention relates to a resonant transmitter circuit and to a contactless power transmission device by inductive resonance coupling for charging or recharging a motor vehicle or any type of vehicle propelled by means of electrical energy.

[0002] In a manner known per se, it is technically possible to supply by contactless transmission a motor vehicle or any other object equipped with an electrical energy storage device with a power of between 3 and 22 kW, when this object is stationary (in this case we speak of a static load), or when it is moving (we then speak of a dynamic load). This supply by contactless transmission is then carried out by means of magnetically coupled remote electrical circuits tuned to the same frequency. The magnetically coupled circuits each comprise at least one resonant LC element, L and C designating inductances and capacitances respectively.

[0003] The problem with this type of solution is that to transmit a satisfactory power level, in particular several kW, it is necessary to operate at high frequencies, in particular of the order of 85 kHz or more, for the 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 at the load.

[0004] Operating at such a high frequency level mainly results in the need to use expensive components such as soft ferrites and Litz conductive wire whose strands are twisted so as to avoid proximity losses, and of very small cross-section, for example less than or equal to 0.07 mm in diameter.

[0005] The invention aims to overcome, at least in part, these drawbacks.

[0006] To this end, the invention relates to a device for contactless power transmission by inductive resonance coupling, in particular for charging or recharging a motor vehicle with electrical energy, comprising: - A resonant transmitter circuit comprising: • a first capacitance C1 of value Cl', • a first winding El comprising: • a first inductance L1 of value LE • a first resistance RI of value RI' - A receiver resonant circuit 2 comprising: • a second capacitance C2 of value C2', • a second winding E2 comprising: • a second inductance L2 of value L2' • a second resistor R2 of value R2' the transmitter resonant circuit having a natural pulsation col such that œl=l / V(Lr x Cl') and a natural frequency fl such that fl = col / (2ir), and the receiver resonant circuit having a natural pulsation co2 such that co2=l / V(L2' x C2') and a natural frequency f2 such that f2 = co2 / (2ir), and such that col = co2, the power transmission device being configured so that: - the transmitter and receiver resonant circuits are in inductively coupled, - the electromotive force induced by the transmitter circuit in the receiver circuit varies in a predetermined manner, - the electromotive force induced by the receiver circuit in the transmitter circuit varies in a predetermined manner.

[0007] The invention makes it possible to increase the amplitude of an electric starting current supplied by the transmitter resonant circuit to the receiver resonant circuit, when the transmitter resonant circuit is magnetically coupled to the receiver resonant circuit.

[0008] According to one aspect of the invention, the receiver resonant circuit is arranged to be tuned to the transmitter resonant circuit, and the receiver resonant circuit and the transmitter resonant circuit have the same natural frequency f 1 = f2 = f, and the same pulsation co2 = col = co.

[0009] According to one aspect of the invention, the two resonant circuits are placed at the resonance pulsation co = l / ^Ll' x Cl') = 1 / V(L2' x C2'). Thus, the resonance and tuning conditions are achieved, so that the voltages across the capacitances Cl, C2 compensate the voltages across the inductances L2, L2.

[0010] The term “electromotive force induced by the transmitter circuit in the receiver circuit” refers to the electromotive force in the receiver circuit varying proportionally to the variations in the total flux on the second inductance L2, therefore to the variations in current in the transmitter circuit.

[0011] Similarly, the term “electromotive force induced by the receiver circuit in the transmitter circuit” denotes the electromotive force in the transmitter circuit varying proportionally to the variations in the total flux on the first inductance L1, therefore to the variations in current in the receiver circuit.

[0012] According to one aspect of the invention, the inductive coupling between the transmitter resonant circuit and the receiver resonant circuit gives rise in each of these circuits to a mutual inductance effect Mo. This mutual inductance will be called in the following “mutual coupling inductance”, because it is linked to a physical coupling of the transmitter and receiver circuits by a magnetic flux.

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[0027] According to one aspect of the invention, this mutual coupling inductance creates in the transmitter circuit a first coupling electromotive force: ei ,-coupling_\\l J 0 dt According to one aspect of the invention, this mutual coupling inductance Mo creates in the receiver circuit a second coupling electromotive force: e} -JM e coupling_2\ 1 J dt According to one aspect of the invention, the transmitter circuit comprises a first mutual control inductance Mcl of value connected in series with the first inductance Ll. This first mutual control inductance produces in the transmitter circuit an electromotive force proportional to the variations of the current Ù of the receiver circuit, called “first control electromotive force”: p ( t} — M ^coHimande_{\1 ) lyl C'tV / dt According to one aspect of the invention, the receiver circuit comprises a second mutual control inductance Mc2 of value Mc2(i) connected in series with the second inductance L2. This second mutual control inductance produces in the receiver circuit an electromotive force proportional to the variations in the current q of the transmitter circuit, called “second control electromotive force”: recommend1 According to one aspect of the invention, the value of the first mutual control inductance MC} varies sinusoidally according to a predetermined frequency f, with a pulsation equal to 2co = 4 / r / , and of amplitude proportional to the mutual inductance Mo. We thus have: gi(0 - According to one aspect of the invention, the value of the second mutual control inductance Mc2 varies sinusoidally according to a predetermined frequency, with a pulsation equal to 2co = 4 / r / , and of amplitude proportional to the mutual inductance Mo; M'cM - *hk2*cos^2wt) According to one aspect of the invention, the predetermined frequency of variation of the values ​​of the mutual control inductances and Mc2 is equal to twice the natural frequency of the receiver resonant circuit and the transmitter resonant circuit to within a tolerance. Such a predetermined frequency allows the amplitude of the current to increase

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[0044] electric current flowing in the receiving resonant circuit. According to one aspect of the invention, the addition in the transmitter circuit of the first mutual control inductance producing in the transmitter circuit an electromotive force proportional to the variations in the current of the receiver circuit amounts to considering a total electromotive force: ^coupling_\ ( 0 L^command_\ ( ) ' di With M] (t ) the total mutual inductance seen by the emitter circuit: =M0+ M C} (t) = + / z  .j*cos(2wf)) According to one aspect of the invention, the addition in the receiver circuit of the second mutual control inductance Mc2, producing in the receiver circuit an electromotive force proportional to the variations in the current q of the transmitter circuit amounts to considering a total electromotive force: ^coupling_2\l 7 T ccommande_2\f / 1 / dt With ( f) the total mutual inductance seen by the emitter circuit: jW2(f) = Mq+ M c2 (0 =Af0*(l+ ^2*cos(2aV)) The invention thus makes it possible to achieve an amplification of the amplitude of the current and the voltage, at the level of the receiver resonant circuit, with an amplification gain sufficiently high to allow operation at a lower frequency, and / or at a greater distance. The invention thus makes it possible, by introducing an amplification gain, to transmit a satisfactory level of power by a contactless method between a resonant transmitter circuit and a resonant receiver circuit, despite the implementation of a very low level frequency compared to the state of the art. According to one aspect of the invention, the parameters hk\ and hk2 can be set to different values ​​in the transmitter circuit and in the receiver circuit. According to one aspect of the invention, the device has a mutual inductance made variable and asymmetric. According to one aspect of the invention, setting the parameters hkl and hk2 to different values ​​makes it possible to maximize the induced electromotive force em2 and to minimize the induced counter electromotive force em\. According to one aspect of the invention, hk\ e [0 ;1], hk2 e [0 ;1] and {hkl, hk2} ^{0,0} According to one aspect of the invention, the mutual inductance is driven in pumping, without resonance. This reduces the number of wires and therefore greatly simplifies the implementation of the solenoid. According to one aspect of the invention, the values ​​and Mc / i) 'a First and of the second mutual control inductance Mcï and vary periodically according to a predetermined frequency f, with a pulsation equal to 2co = 4îtf, in a non-sinusoidal manner, and with an amplitude proportional to the mutual inductance MQ.

[0045] According to one aspect of the invention, the values ​​and comprise har moniques in with j > 1: [0°46] , * hkifC0^jœt + (pki / )

[0047] With ie [1;2], and m > 1, notably m = 3 or m = 5.

[0048] According to one aspect of the invention, the introduction of harmonics on the values ​​of the mutual control inductances makes it possible to reduce, in particular to eliminate the creation of higher order harmonics on the values ​​of the currents t) and / ? ( t ) passing through the transmitter and receiver resonant circuits.

[0049] According to one aspect of the invention, the frequency / = ^ is chosen so that the maximum frequency of the harmonics f — is less than or equal to 500Hz, in particular less than or equal to 300Hz.

[0050] According to one aspect of the invention, the maximum frequency f is thus in the Ultra Low Frequency (UBF) domain as described previously.

[0051] According to one aspect of the invention, the first mutual control inductance and / or the second mutual control inductance is formed by an electronic voltage inverter arranged to emulate the electrical behavior of the mutual control inductance*

[0052] According to one aspect of the invention, the first mutual control inductance is formed by a first electronic voltage inverter arranged to emulate the electrical behavior of the mutual control inductance Mci and the value of the inductance M cr

[0053] According to one aspect of the invention, the second mutual control inductance is formed by a second electronic voltage inverter arranged to emulate the electrical behavior of the mutual control inductance Mc2 and the value of the inductance M c2-

[0054] According to one aspect of the invention, at least one of the electronic voltage inverters comprises power components, for example IGBT type transistors forming at least two arms.

[0055] According to one aspect of the invention, at least one electronic voltage inverter delivers an alternating voltage controlled by means of a direct current control voltage.

[0056] According to one aspect of the invention, at least one electronic voltage inverter has two connection terminals between which the alternating voltage is delivered, these two connection terminals being the two terminals between which the inductance mutual order is emulated.

[0057] According to one aspect of the invention, the direct current control voltage is provided by a power supply capable of delivering a power greater than or equal to the power to be transmitted by the resonant inductive coupling.

[0058] According to one aspect of the invention, at least one mutual control inductance comprises a magnetic circuit.

[0059] According to one aspect of the invention, the inductance value of at least one mutual control inductance varies by varying the reluctance of the magnetic circuit of the mutual control inductance.

[0060] According to one aspect of the invention, the magnetic circuit of the at least one mutual control inductance comprises at least one movable part, relative to the second winding.

[0061] According to one aspect of the invention, the magnetic circuit of the at least one mutual control inductance comprises at least one fixed part, relative to the second winding.

[0062] According to one aspect of the invention, the fixed part and the mobile part comprise a ferromagnetic or ferrimagnetic material.

[0063] According to one aspect of the invention, the movable part is set in motion so that projections are alternately facing other projections or between two projections.

[0064] According to one aspect of the invention, the moving part of the magnetic circuit of the at least one mutual control inductance is driven by an electric motor.

[0065] According to one aspect of the invention, the at least one mutual control inductance is made in one piece.

[0066] According to one aspect of the invention, the at least one mutual control inductance 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 comprising a solenoid and a plurality of stator arms, the set of stator arms forming a single magnetic pole when the solenoid is traversed by an electric current and the pole being considered in particular on the air gap side, - the rotor comprising a plurality of rotor arms forming a single magnetic pole when the solenoid is traversed by an electric current and the pole being considered in particular on the air gap side.

[0067] According to one aspect of the invention, the first mutual control inductance and the second mutual control inductance comprise a single variable magnetic reluctance assembly arranged to produce a variable common flux.

[0068] According to one aspect of the invention, two adjacent rotor arms are separated two by two by a non-magnetic portion.

[0069] According to one aspect of the invention, two adjacent stator arms are separated two by two by a non-magnetic portion.

[0070] According to one aspect of the invention, the number of stator arms is equal to the number of rotor arms.

[0071] Alternatively, the number of stator arms is different from the number of rotor arms.

[0072] According to one aspect of the invention, each stator arm extends in a radial direction relative to the axis of rotation of the rotor and comprises a laminated magnetic sheet stack, the stacking of which is in particular carried out in an orthoradial direction relative to the radial direction in which the stator arm extends.

[0073] According to one aspect of the invention, the stacking is carried out in an orthoradial direction relative to the axis of rotation of the rotor.

[0074] Alternatively, the stacking is carried out in a direction parallel to the axis of rotation of the rotor.

[0075] According to one aspect of the invention, each rotor arm extends in a radial direction relative to the axis of rotation of the rotor and comprises a laminated magnetic sheet stack, the stacking of which is in particular carried out in an orthoradial direction relative to the radial direction in which the rotor arm extends.

[0076] According to one aspect of the invention, the stack is produced in an orthoradial direction relative to the axis of rotation of the rotor.

[0077] Alternatively, the stacking is carried out in a direction parallel to the axis of rotation of the rotor.

[0078] According to one aspect of the invention, the rotor comprises a non-magnetic shaft.

[0079] This allows the flow to pass only through the rotor arms and not through the shaft, in an axial direction.

[0080] According to one aspect of the invention, each rotor arm comprises a projecting portion, in particular arranged radially on the side of the axis of rotation of the rotor.

[0081] This allows the rotor arms to be held securely on the shaft and limits leakage flows by channeling the magnetic flux from an external magnetic source.

[0082] According to one aspect of the invention, the rotor is coupled to a motor to enable it to be driven in rotation, in particular at a predetermined speed Q, this speed being expressed in revolutions / s and being such that Q = ((2 xf) ± e / (N), N being the number of stator arms, and f = fl = f2 being the resonant frequency of the transmitting and receiving resonant circuits.

[0083] According to one aspect of the invention, the power transmission device comprises at least one control unit arranged to control a mutual control inductance, and at least one mutual control inductance is electrically connected to a control unit

[0084] In particular, the first mutual control inductance and the second mutual control inductance are electrically connected to a control unit.

[0085] According to one aspect of the invention, at least one electronic voltage inverter is electrically connected to a control unit, arranged to control the electronic voltage inverter.

[0086] According to one aspect of the invention, at least one variable magnetic reluctance assembly is electrically connected to a control unit, arranged to control the variable magnetic reluctance assembly.

[0087] According to one aspect of the invention, the second capacitance C2 comprises a polypropylene capacitor, in particular of at least 90 pF, for example of at least 900 pF.

[0088] According to one aspect of the invention, the capacitances C1 and C2, as well as the resistances R1 and R2 have a substantially constant value. By substantially constant value is meant the value of this capacitance, not including variations thereof linked to temperature or wear or any other physical factor.

[0089] According to one aspect of the invention, the power transmission device comprises at least one current measurement unit.

[0090] According to one aspect of the invention, the power transmission device comprises a first current measuring unit arranged to measure the current flowing in the transmitter resonant circuit and a second current measuring unit arranged to measure the current flowing in the receiver resonant circuit.

[0091] According to one aspect of the invention, the power transmission device comprises an electrically connected control unit: - At the first mutual control inductance - At the second mutual control inductance - To the first current measurement unit - To the second current measurement unit.

[0092] According to one aspect of the invention, the control unit is arranged to control the value of the first mutual control inductance M cï and the second mutual control inductance M by the electronic voltage inverters and / or the variable magnetic reluctance assemblies of the transmitter and receiver circuits.

[0093] According to one aspect of the invention, the control unit is arranged to control the value of the first mutual control inductance M CA and the second mutual control inductance M c2 as a function of the currents i^t) and circulating respectively in the transmitter and receiver resonant circuits and measured respectively by the first and second current measurement units.

[0094] In particular, the control unit is arranged to control the value of the first mutual control inductance Mcl as a function of the current i2(t) flowing in the receiver resonant circuit and measured by the second current measurement unit, and to control the value of the second mutual control inductance M C9 as a function of the currents flowing in the transmitter resonant circuits and measured by the first current measurement unit. [Added for clarification]

[0095] According to another embodiment of the invention, the power transmission device comprises: - a first control unit electrically connected to the transmitter resonant circuit and arranged to control the value of the first mutual control inductance M by the first electronic voltage inverter and / or the variable magnetic reluctance assembly of the transmitter circuits, as a function of the current q(t) flowing in the transmitter resonant circuit and measured by the first current measuring unit. - a second control unit electrically connected to the receiver resonant circuit and arranged to control the value of the second mutual control inductance M r7 by the second electronic voltage inverter and / or the variable magnetic reluctance assembly of the receiver circuits, as a function of the current flowing in the receiver resonant circuit and measured by the second current measuring unit.

[0096] According to one aspect of the invention, the transmitter and receiver resonant circuits are placed in sinusoidal mode. The currents ^( / ) and i2( t) can therefore be considered as complex variables.

[0097] According to one aspect of the invention, the transmitter and receiver resonant circuits are placed at resonance, coupled and tuned. The currents and i2 ( t ) are therefore in quadrature, and we have the following relationships between the currents ij and / 2:

[0098] / Jr) = jXvi2(t) = -J-Kz-ifa)

[0099] With and K2 real coefficients belonging to the interval [0, 2], in particular

[0100] belonging to the interval [0.8, 1.2], in particular with KY = K2 = 1

[0101] According to one aspect of the invention, the first control unit is arranged to estimate the variations of the current i^(t) flowing in the receiver resonant circuit from the current flowing in the transmitter resonant circuit and measured by the first current measurement unit.

[0102] According to one aspect of the invention, the second control unit is arranged to estimate the variations of the current flowing in the transmitter resonant circuit from the current i2(t) flowing in the receiver resonant circuit and measured by the second unit of current measurement.

[0103] Advantageously, this embodiment makes it possible to achieve a contactless power transmission without transmission of information between the transmitter resonant circuit and the receiver resonant circuit, in particular between the first and second control units.

[0104] According to one aspect of the invention, the contactless power transmission device is arranged to carry out inductive wireless charging of an electrical energy storage device, in particular a battery, in particular a battery of an electric vehicle.

[0105] According to one aspect of the invention, the device for contactless power transmission by inductive resonance coupling comprises an energy source, in particular alternating current of frequency f and pulsation co = 2ît / , generating a voltage:

[0106] z / j (?) = t70*co^w?-f)

[0107] According to one aspect of the invention, the control of the values ​​of the mutual control inductances:

[0108] [OK)9] M'c2(t) = M^hk2*co^2Mt)

[0110] is carried out with an advance of y relative to the energy source.

[0111] According to another embodiment of the invention, the energy source generates a tension : [0H2] (?) = £Z0*sin(ü??) = t70*cos(ûj? + y)

[0113] and the control of the values ​​of the mutual control inductances: [0H4] M'cl(t) = M^hk^co^2œt)

[0115] M'c2(t) = M o *hk2 *co^2m?j

[0116] is performed with a delay of y relative to the energy source.

[0117] According to one aspect of the invention, the resonant transmitter circuit is powered by the energy source.

[0118] According to one aspect of the invention, the power transmission is carried out at Ultra Low Frequencies (UBF) i.e. with f between 300 Hz and 3 kHz.

[0119] According to one aspect of the invention, the power transmission device is arranged to carry out a power transmission of between 1 kW and 500 kW, in particular between 1 kW and 150 kW.

[0120] The invention also relates to a contactless charging or recharging assembly for a motor vehicle, comprising: - a contactless power transmission device by inductive coupling to resonance as described previously - a resistive load, in particular a battery of an electric vehicle, coupled to the receiving resonant circuit, this resistive load having an equivalent impedance, the contactless power transmission device being arranged to perform power transmission directed towards the resistive load.

[0121] According to one aspect of the invention, the contactless charging or recharging assembly of an electric vehicle comprises a decoupling assembly arranged to decouple the equivalent impedance of the resistive load, in particular a vehicle battery, from the recharging power, this decoupling assembly comprising a rectifier arranged to provide a direct voltage to supply recharging power to the resistive load, and an impedance matching assembly which is arranged to, at a given recharging power, vary the equivalent impedance of the resistive load.

[0122] According to one aspect of the invention, the equivalent impedance of the resistive load is represented by the ratio V / l where V is the voltage across the impedance matching assembly and I the intensity of the current flowing through it.

[0123] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0124] [Fig.l] is a schematic representation of a contactless charging or recharging assembly for a motor vehicle according to the invention;

[0125] [Fig.2] is a schematic representation of a contactless power transmission device by resonant inductive coupling according to the invention;

[0126] [Fig. 3] is a schematic representation of a variable magnetic reluctance assembly according to the invention; and

[0127] [Fig.4] is a schematic representation of the whole of [Fig.3], according to section AA;

[0128] [Fig.5] is a schematic representation of a second inductance according to the invention;

[0129] [Fig.6] is a representation of the time evolutions of the voltage u_(l ) (t) generated by the energy source, the voltage u_2 (t) at the terminals of the resistive load, and the currents i_l (t) and i_2 (t) circulating respectively in the transmitter and receiver circuits.

[0130] The features, variants and different embodiments of the invention may be combined with each other, in various combinations, to the extent that they are not incompatible or mutually exclusive with respect to the others. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0131] As visible in [Fig.l], 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) as well as the on-board network of the motor vehicle 30. 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 using a contactless power transmission device by resonant inductive coupling 200.

[0132] The battery 20 of the vehicle 30 is a resistive load having an equivalent impedance, and the contactless power transmission device is arranged to perform power transmission directed towards the resistive load.

[0133] The charging assembly 100 or contactless recharging of an electric vehicle comprises a decoupling assembly arranged to decouple the equivalent impedance of the vehicle battery from the recharging power, this decoupling assembly comprising a rectifier 12 arranged to provide a direct voltage to supply recharging power to the resistive load, and an impedance matching assembly which is arranged to, at a given recharging power, vary the equivalent impedance of the resistive load.

[0134] In the example of [Fig.l], the contactless power transmission device by resonant inductive coupling 200 comprises an alternating current energy source 10 supplying the rectifier 12, this rectifier 12 being electrically connected to an inverter 13 which thus supplies a resonant transmitter circuit 1 with alternating current at a frequency higher than that of the source 10. Alternatively, the energy source 10 could be at a frequency that can be used directly without requiring the use of a rectifier 12 and an inverter 13. In the example of [Fig.l], it is the winding E0 which is supplied via the wired connection to the energy source 10. This winding E0 then supplies the resonant transmitter circuit 1 by inductive coupling.

[0135] In a variant not shown, the alternating current energy source 10 could directly supply the resonant emitter circuit 1 with alternating current.

[0136] In the example of [Fig.l], the receiver resonant circuit 2 comprises a second capacitance C2 of value C2' and a second winding E2.

[0137] The resonant emitter circuit 1 comprises a first capacitance Cl of value Cl' and a first winding EL

[0138] When the receiver resonant circuit 2 is magnetically coupled to the resonant circuit transmitter 1, there is contactless power transmission by inductive resonance coupling to the receiver circuit 2. This magnetic coupling takes place when the first El and second E2 windings are close to each other. In the example considered, this coupling takes place when the first El 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.

[0139] As seen in [Fig.2], the energy source 10 is connected to a resistor RO in series with a transmission coil LO. The winding E0 shown in [Fig.l] in fact includes the parasitic resistance RO in series with a transmission coil LO. In [Fig.2], the rectifier 12 and the inverter 13 have not been shown for simplicity.

[0140] As seen in [Fig.2], the receiver resonant circuit 2 consists of a circuit RLC. In fact, the second winding E2 has a second inductance L2 of value L2' in series with a second resistor R2 of value R2', in series with the second capacitance C2.

[0141] The transmitting coil L0 is magnetically coupled to the first inductance LL

[0142] The transmitting resonant circuit 1 consists of an RLC circuit. Indeed, the first winding El comprises a first inductance L1 of value Ll' in series with a first resistance RI of value RI', in series with the first capacitance CL

[0143] The second capacitance C2 comprises a polypropylene capacitor, of at least 900 pF.

[0144] In the example shown, the receiver resonant circuit 2 and the transmitter resonant circuit 1 are in inductively coupled.

[0145] The resonant transmitter circuit has a natural pulsation such that

[0146] col=1 A / (L1 ' x Cl') and a natural frequency fl such that fl = col / (2ir), the circuit resonant receiver a natural pulsation co2 such that co2=l / V(L2' x C2') and a natural frequency f2 such that f2 = co2 / (2ir), and such that col = co2.

[0147] The receiver resonant circuit is arranged to be tuned to the transmitter resonant circuit. Consequently, the receiver resonant circuit and the transmitter resonant circuit have the same natural frequency f 1 = f2 = f, and the same angular frequency co2 = col = co.

[0148] As seen in [Fig.2], a receiving 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.l].

[0149] The winding E3 shown in [Fig.l] here includes the parasitic resistance in series with the receiving coil L3.

[0150] The receiving coil L3 is magnetically coupled to the second inductor L2.

[0151] In the example of Figures 1 and 2, the transmitter resonant circuit 2 and the coil LO transmitters are located on the ground, while the receiver resonant circuit 1 and the receiver coil L3 are located on board the vehicle.

[0152] The two resonant circuits are placed at the resonance pulsation co = 1 / V(L1' x Cl') = 1 / V(L2' x C2'). Thus, the resonance and tuning conditions are achieved, so that the voltages across the capacitances Cl, C2 compensate the voltages across the inductances L2, L2.

[0153] The inductive coupling between the transmitter resonant circuit 1 and the receiver resonant circuit 2 gives rise in each of these circuits to a mutual inductance effect Mo called in the following “mutual coupling inductance”.

[0154] This mutual coupling inductance Mo creates in the transmitter circuit 1 a first electromotive coupling force:

[0155] '■•neck beach JW1- J

[0156] And in the receiver circuit 2 a second coupling electromotive force:

[0157] ^coupling_2\l / J;

[0158] The transmitter circuit 1 comprises a first mutual control inductance Mcf of value Mc^ mounted in series with the first inductance LL. This first mutual control inductance produces in the transmitter circuit 1 an electromotive force:

[0159] _ ( e orderJ\t) dT

[0160] The value varies sinusoidally according to a predetermined frequency f, with a pulsation equal to 2co = 4tt / , and of amplitude proportional to the mutual inductance Mo; [°161] = Mo* / 41*cos(2m / )

[0162] Similarly, the receiver circuit 2 comprises a second mutual control inductance Mc2 of value Mc2 V) connected in series with the second inductance L2. This second mutual control inductance produces in the receiver circuit 2 a second control electromotive force:

[0163] e , ,(O = M commandJ2 \ 1 ) 1V1 ClyJ dt

[0164] The value Mc^ of the second mutual control inductance Mc2 varies sinusoidally according to a predetermined frequency, with a pulsation equal to 2co = 4^ / , and of amplitude proportional to the mutual inductance A70.

[0165] 'c^i) = *cos(2 wr)

[0166] The value ( t ) varies with a phase shift or - relative to the voltage ( / ) of the energy source 10.

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[0176]

[0177]

[0178]

[0179]

[0180] The predetermined frequency of variation of the values ​​of the mutual control inductances and Mc2 is equal to twice the natural frequency of the receiver resonant circuit 2 and the transmitter resonant circuit 1 within a tolerance. Such a predetermined frequency makes it possible to increase the amplitude of the electric current flowing in the receiver resonant circuit 2. The invention thus makes it possible to increase the amplitude of an electric starting current supplied by the transmitter resonant circuit 1 to the receiver resonant circuit 2, when the transmitter resonant circuit is magnetically coupled to the receiver resonant circuit 2. The addition in the transmitter circuit 1 of the first mutual control inductance Met producing in the transmitter circuit an electromotive force proportional to the variations of the current û of the receiver circuit amounts to considering a total electromotive force: ^coupling_\( 0 "b ^cormnande_\ ( O 0 dt With Mj ( t ) the total mutual inductance seen by the emitter circuit: —Mq+ MC}(t) =MO^1+ Similarly, the addition in the receiver resonant circuit 2 of the second mutual control inductance Mc2, producing in the receiver circuit an electromotive force proportional to the variations of the current q of the transmitter circuit 1 amounts to considering a total electromotive force: di i(t) dt &coupling_2( 0 ^command_2( / ) M( t ) * With M। ( t ) the total mutual inductance seen by the emitter circuit: M2(t) = M0+ Mc2(t) =MO\1+ ^2*cos(2w0) The electromotive force induced by the transmitter resonant circuit 1 in the receiver circuit 2 and the electromotive force induced by the receiver circuit 2 in the transmitter circuit 1 vary in a predetermined manner. The parameters hki and hk2 can be set to different values ​​in the transmitter circuit 1 and in the receiver circuit 2, these values ​​being included in the interval [0,1], and at least one of these parameters being non-zero. The device 200 therefore has a mutual inductance made variable and asymmetric, which makes it possible to maximize the induced electromotive force em2 and to minimize the induced counter electromotive force emi. The invention thus makes it possible to achieve an amplification of the amplitude of the current and the voltage, at the level of the receiver resonant circuit, with an amplification gain sufficiently high to allow operation at a lower frequency, and / or at a greater distance.

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192] of the first and second mutual inductance The mutual inductance is driven by pumping, without resonance. The values ​​and M control circuits MCi and Mc2 vary periodically according to a predetermined frequency f, with a pulsation equal to 2co = 4æ / , in a non-sinusoidal manner, and with an amplitude proportional to the mutual inductance Mo. In an embodiment not shown, the values ​​and comprise harmonics with j > 1: With i G [1;2], and m > 1, notably m = 3 or m = 5. The introduction of harmonics on the values ​​of the mutual control inductances makes it possible to reduce, in particular to eliminate the creation of higher order harmonics on the values ​​of the currents f) and i2(t) crossing the resonant circuits transmitter 1 and receiver 2. The frequency f — % is then chosen so that the maximum frequency of the harmonics f — is less than or equal to 500Hz, in particular less than or equal to 300Hz and thus remains in the Ultra Low Frequency (UBF) domain. The capacitances Cl and C2, as well as the resistances RI and R2, have a substantially constant value. By substantially constant value, we mean the value of this capacitance, not including variations in it linked to temperature or wear or any other physical factor. The power transmission device 200 is arranged to carry out a power transmission of between 1 kW and 500 kW, in particular between 1 kW and 150 kW, in Ultra Low Frequencies (UBF) i.e. with f of between 300 Hz and 3 kHz. The power transmission device 200 comprises a first current measuring unit 50 arranged to measure the current flowing in the transmitter resonant circuit 1 and a second current measuring unit 51 arranged to measure the current flowing in the receiver resonant circuit 2. The power transmission device comprises a control unit 60 electrically connected: - At the first mutual control inductance - At the second mutual control inductance - To the first current measuring unit 50 and to the second current measuring unit 51. According to one aspect of the invention, the control unit 60 is arranged to control the value of the first mutual control inductance M Ci and the second mutual control inductance M C7 as a function of the currents and circulating respectively in the transmitter 1 and receiver 2 resonant circuits and measured respectively by the first 50 and second 51 current measuring units.

[0193] In particular, the control unit 60 is arranged to control the value of the first mutual control inductance M as a function of the current flowing in the receiver resonant circuit 2 and measured by the second current measurement unit 51, and to control the value of the second mutual control inductance M c-> as a function of the current flowing in the transmitter resonant circuit 1 and measured by the first current measurement unit 50.

[0194] According to another embodiment not shown, the power transmission device comprises: - a first control unit electrically connected to the emitter resonant circuit and arranged to control the value of the first mutual control inductance M ci as a function of the current q(t) flowing in the emitter resonant circuit and measured by the first current measuring unit. - a second control unit electrically connected to the receiving resonant circuit and arranged to control the value of the second mutual control inductance M c2 as a function of the current flowing in the receiving resonant circuit and measured by the second current measuring unit.

[0195] The first control unit is arranged to estimate the variations of the current ü2(t) flowing in the receiver resonant circuit from the current î^t) flowing in the transmitter resonant circuit and measured by the first current measurement unit, and the second control unit is arranged to estimate the variations of the current flowing in the transmitter resonant circuit from the current flowing in the receiver resonant circuit and measured by the second current measurement unit.

[0196] Advantageously, this embodiment makes it possible to achieve a contactless power transmission without transmission of information between the transmitter resonant circuit and the receiver resonant circuit, in particular between the first and second control units.

[0197] An example of the embodiment of a mutual control inductance is described in connection with [Fig.5].

[0198] This embodiment example can for example be used to produce the first mutual control inductance, the second mutual control inductance Met, or the two mutual control inductances. In the remainder of the description, we will simply refer to a mutual control inductance Mc of value M'c,

[0199] The mutual control inductance Mc is formed by an electronic voltage inverter 9 arranged to emulate the electrical behavior of the mutual control inductance Mc and the value of the inductance M c-

[0200] The electronic voltage inverter 9 comprises power components, in particular IGBT type transistors forming at least two arms.

[0201] The electronic voltage inverter 9 delivers an alternating voltage controlled by means of a direct control voltage VDC.

[0202] The direct control voltage VDC is provided by a power supply capable of delivering a power greater than or equal to the power to be transmitted by the inductive resonance coupling.

[0203] The electronic voltage inverter 9 has two connection terminals between which the alternating voltage is delivered, these two connection terminals being the two terminals between which the mutual control inductance is emulated.

[0204] The electronic voltage inverter 9 is electrically connected to a control unit arranged to control the electronic voltage inverter.

[0205] Another example of the embodiment of a mutual control inductance is shown in Figures 3 and 4.

[0206] The mutual control inductance Mc comprises a magnetic circuit, and its inductance value varies by varying the reluctance of the magnetic circuit.

[0207] The magnetic circuit of the mutual control inductance Mc comprises a movable part, relative to the second winding, and at least one fixed part, relative to the second winding.

[0208] The fixed part and the moving part comprise a ferromagnetic or ferrimagnetic material.

[0209] The moving part is driven by an electric motor so that projections are alternately located opposite other projections or between two projections.

[0210] The mutual control inductance is in this example 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 carries an electric current. The pole is here considered on the air gap side. The rotor 6 comprises a plurality of rotor arms 7 forming a single magnetic pole when the solenoid 5 carries an electric current. The pole is here considered on the air gap side.

[0211] Thus, the solenoid 5 constitutes a winding. The stator constitutes a fixed part and the rotor constitutes a movable part, relative to the winding.

[0212] As can be seen in [Fig.3], two adjacent rotor arms 7 are separated two by two by a non-magnetic portion and two adjacent stator arms 4 are separated two by two 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.

[0213] Thus, the stator 3 has a plurality of protrusions, all of the same polarity, this polarity in the direction of the north or south orientation, being a function of the phase of the current passing through the solenoid 5. Furthermore, the rotor 6 has a plurality of protrusions, all of the same polarity, this polarity in the direction of the north or south orientation, being a function of the phase of the current passing through the solenoid 5. The stator 3 and the rotor 6 each have the same number of magnetic protrusions, separated by absences of magnetic material.

[0214] Each stator arm 4 extends in a radial direction relative to the axis of rotation X of the rotor and comprises a laminated magnetic sheet stack, the stacking of which is carried out in an orthoradial direction relative to the radial direction in which the stator arm 4 extends. In the example considered, the stacking is carried out in an orthoradial direction relative to the axis of rotation X of the rotor 6.

[0215] Each rotor arm 7 extends in a radial direction relative to the axis of rotation X of the rotor and comprises a laminated magnetic sheet stack, the stacking of which is carried out in an orthoradial direction relative to the radial direction in which the rotor arm 7 extends. In the example considered, the stacking is carried out in an orthoradial direction relative to the axis of rotation X of the rotor.

[0216] The rotor 6 comprises a shaft 8 which is made of a non-magnetic material. This allows the flux to pass only through the rotor arms 7 and not through the shaft 8, in an axial direction.

[0217] In the example considered, the non-magnetic 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.

[0218] As can be seen in [Fig.4], each rotor arm 7 comprises a projecting portion, in particular arranged 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.

[0219] In the example of [Fig.3], the solenoid 5 comprises a plurality of turns extending concentrically. In the example of [Fig.4], the solenoid 5 may comprise a plurality of turns extending axially. In a variant not shown, the solenoid 5 may comprise a single flat turn.

[0220] The turns are devoid of Litz wire. Alternatively, the turns comprise Litz wire whose cross-section has a diameter strictly greater than 0.2 mm, in particular strictly greater than 0.3 mm.

[0221] The solenoid 5 is arranged so that an alternating current circulating in the turns composing it has a frequency strictly lower than 3 kHz.

[0222] An electric motor, not shown, is coupled to the shaft 8 to enable the rotor 6 to rotate at a predetermined speed Q expressed in revolutions / s and being such that Q = ((2xf0) ± e / (N), N being the number of stator arms 4. This predetermined speed is considered in steady state, that is to say at the end of an electromechanical transient state.

[0223] The variable magnetic reluctance assembly is electrically connected to a control unit not shown in the figures, and arranged to control the variable magnetic reluctance assembly

[0224] Figure 6 shows the time evolutions of the voltage ( t ) generated by the energy source, the voltage u-, ( t ) at the terminals of the resistive load, and the currents and i2(j) circulating respectively in the transmitter and receiver circuits.

[0225] The transmitter and receiver resonant circuits are placed in sinusoidal mode. We can therefore consider the currents and i2(0 as being complex variables.

[0226] The transmitter and receiver resonant circuits are placed at resonance, coupled and tuned. The currents ( t ) and i2 ( t ) are therefore in quadrature, and we have the following relationships between the currents i] and i2:

[0227] i{( t ) = jXvi2 ( t ) and i2 ( t ) = - jX^i^t)

[0228] With and K2 real coefficients belonging to the interval [0, 2], in particular

[0229] belonging to the interval [0.8, 1.2], in particular with = K2 = 1.

[0230] The energy source generates a voltage of frequency f and pulsation co = 2tt / , generating a voltage:

[0231] = t / 0*COs(wf-j)

[0232] The control of the values ​​of the mutual control inductances:

[0233] =

[0234] =

[0235] is carried out with an advance of y relative to the energy source.

[0236] In another embodiment of the invention not shown, the energy source generates a voltage:

[0237] Uï (t) = t / 0*sin((üt) = t / 0*COs(û^ +f)

[0238] and the control of the values ​​of the mutual control inductances:

[0239]

[0240] wc2(ÿ—

[0241] is carried out with a delay of ir / 2 relative to the energy source.

[0242] Of course, the preceding description has been given by way of example only and does not limit the scope of the invention, which would not be exceeded by replacing the various elements with any other equivalents.

[0243] Furthermore, the various features, variations, and / or embodiments of the present invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive.

Claims

Claims

1. Contactless power transmission device (200) by resonant inductive coupling, in particular for charging or recharging a motor vehicle (30) with electrical energy, comprising: - a resonant transmitter circuit (1) comprising: • a first capacitance C1 of value Cl', • a first winding El comprising: • a first inductance L1 of value LE • a first resistance RI of value RI' - a resonant receiver circuit (2) comprising: • a second capacitance C2 of value C2', • a second winding E2 comprising: • a second inductance L2 of value L2' • a second resistor R2 of value R2' the transmitter resonant circuit having a natural pulsation col such that col=l / V(Lr x Cl') and a natural frequency fl such that fl = col / (2ir), and the receiver resonant circuit having a natural pulsation co2 such that co2=l / V(L2' x C2') and a natural frequency f2 such that f2 = co2 / (2ir), and such that col = co2, the power transmission device (200) being configured so that: - the resonant transmitter (1) and receiver (2) circuits are in inductively coupled, - the electromotive force induced by the transmitter circuit (1) in the receiver circuit (2) varies in a predetermined manner, - the electromotive force induced by the receiver circuit (2) in the transmitter circuit (1) varies in a predetermined manner.

2. Device (200) according to claim 1, wherein the receiver resonant circuit is arranged to be tuned to the transmitter resonant circuit, and the receiver resonant circuit and the transmitter resonant circuit have the same natural frequency f 1 = f2 = f, and the same angular frequency co2 = col = co.

3. Device (200) according to claim 2, wherein the two resonant circuits are placed at the resonance pulsation co = 1 / 'V(L1 ' x Cl') = 1 / V(L2' x C2'), so that the resonance and tuning conditions are reached, and the voltages across the capacitances Cl, C2 compensate the voltages across the inductances L2, L2.

4. Device (200) according to one of the preceding claims, in which the transmitter circuit comprises a first mutual control inductance of value connected in series with the first inductance L1. This first mutual control inductance produces in the transmitter circuit an electromotive force proportional to the variations of the current / 2 of the receiver circuit, called "first control electromotive force": / x » r' / X.'.diM & , M tH—. ^command^ïy1 J (Ayj dt

5. Device (200) according to claim 4, in which the value M( of the first mutual control inductance varies sinusoidally according to a predetermined frequency f, with a pulsation equal to 2co = 4tf / , and of amplitude proportional to the mutual inductance Mq. We thus have:

6. Device (200) according to one of the preceding claims, in which the receiver resonant circuit comprises a second mutual control inductance Mc2 of value Mc2(i) connected in series with the second inductance L2. This second mutual control inductance produces in the receiver resonant circuit an electromotive force proportional to the variations of the current q of the transmitter resonant circuit, called "second control electromotive force": / x , y / \.i.£ / q(0 ^commandC-Z V / C 2( / dt

7. Device (200) according to claim 6, wherein the value of the second mutual control inductance Mc2 varies sinusoidally according to a predetermined frequency, with a pulsation equal to 2co = 4njf, and of amplitude proportional to the mutual inductance We thus have: M *hk2 *cos(2 w / )

8. Device (200) according to one of claims 4 to 7, wherein the first mutual control inductance and / or the second mutual control inductance Mc2 is formed by an electronic voltage inverter (9) arranged to emulate the electrical behavior of the mutual control inductance*

9. Device (200) according to one of claims 4 to 7, in which the first mutual control inductance Mc{ and / or the second mutual control inductance Mc2 is 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 comprising a solenoid (5) and a plurality of stator arms (4), the set of stator arms forming a single magnetic pole when the solenoid (5) is traversed by an electric current and the pole being considered in particular on the side of the air gap, - the rotor (6) comprising 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 considered in particular on the side of the air gap.

10. Device (200) according to one of claims 4 to 7, comprising at least one control unit arranged to control a mutual control inductance, and wherein at least one mutual control inductance is electrically connected to a control unit (60).

11. Device (200) according to one of the preceding claims, comprising at least one current measuring unit (50, 51).

12. Device (200) according to claim 10, comprising a first current measuring unit (50) arranged to measure the current flowing in the transmitter resonant circuit (1) and a second current measuring unit (51) arranged to measure the current flowing in the receiver resonant circuit (2).

13. Device (200) according to one of claims 10 to 11, comprising an electrically connected control unit: - To the first mutual control inductance - To the second mutual control inductance Mc2, - To the first current measuring unit (50), - To the second current measuring unit (51). the control unit being arranged to control the value of the first mutual control inductance M cl and of the second mutual control inductance M c2 By 'cs electronic voltage inverters (90) and / or the variable magnetic reluctance assemblies of the transmitter (1) and receiver (2) circuits.

14. Device (200) according to one of claims 10 to 11, comprising: - a first control unit electrically connected to the transmitter resonant circuit (1) and arranged to control the value of the first mutual control inductance M Cl by the first electronic voltage inverter (9) and / or the variable magnetic reluctance assembly of the transmitter circuits (1), as a function of the current ij(t) flowing in the transmitter resonant circuit (1) and measured by the first current measuring unit (50). - a second control unit electrically connected to the receiver resonant circuit (2) and arranged to control the value of the second mutual control inductance M c2 by the second electronic voltage inverter (9) and / or the variable magnetic reluctance assembly of the receiver circuit (2), as a function of the current flowing in the receiver resonant circuit and measured by the second current measuring unit.

15. Device (1) according to one of the preceding claims, comprising an energy source, in particular alternating current of frequency f and pulsation co = 2^ / , generating a voltage: - î / 0*sin(a?f) = and such that the resonant emitter circuit is powered by the energy source.

16. Device (1) according to claims 6 and 15, and potentially one of the other preceding claims, wherein the value Mc2(f) varies with a phase shift y or - y relative to the voltage of the energy source.

17. Contactless charging or recharging assembly (100) for a motor vehicle (30), comprising: - a contactless power transmission device (200) by inductive resonance coupling according to any one of the preceding claims, - a resistive load, in particular a battery (20) of an electric vehicle (30), coupled to the receiving resonant circuit (1), this resistive load having an equivalent impedance, the contactless power transmission device (100) being arranged to perform a power transmission directed towards the resistive load.

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