WPT anti-offset and anti-deflection method and system based on rotating magnetic field coupling

Abstract

The application provides a WPT anti-deviation and anti-deflection method and system based on a rotating magnetic field coupling, and relates to the field of physics.The method comprises the following steps: constructing a WPT system, generating high-frequency voltages by using two-way inverters, and supplying a DQDD-CD coupling mechanism through an LCC-S resonance topology; loading orthogonal currents on a transmitting coil of the DQDD-CD coupling mechanism so that the excited magnetic field rotates periodically, and the DQDD-CD coupling mechanism picks up the excited magnetic flux through a receiving coil under a large range of deviation and deflection positions; two-way energy channels respectively pass through compensation capacitors and enter a rectifier circuit, and finally provide electric energy for a load; element configuration parameters of a resonance circuit and a system transmission energy efficiency expression are obtained based on the WPT system, and an LCC-S resonance element configuration method with optimal anti-deviation and anti-deflection performance is obtained according to the expression.In addition, the application also provides a WPT system based on the above method, which has good anti-deviation and anti-deflection performance.

Description

Technical Field

[0001] This invention relates to the field of physics, and more specifically, to a WPT anti-deflection and anti-rotation method and system based on rotating magnetic field coupling. Background Technology

[0002] Wireless Power Transfer (WPT) technology enables contactless charging and has become a research hotspot in the field of electric vehicle charging systems due to its advantages such as no contact loss, convenience, flexibility, and immunity to harsh outdoor environments. With the increasing demand for parking space flexibility in various applications, the anti-offset deflection characteristics of WPT systems have become one of the research focuses. The anti-offset deflection characteristics of the coupling mechanism mainly include offset in the horizontal direction, offset in the vertical direction, and deflection. These factors all affect the coupling coefficient between the transmitting and receiving coils. Therefore, to expand the charging area, the WPT system must be insensitive to offset and deflection, while ensuring the stability of the power picked up by the onboard receiver is a key issue that needs to be addressed in electric vehicle WPT systems. To improve the anti-offset deflection performance of WPT systems, existing literature mainly employs three methods: adding energy coupling channels, optimizing the spatial distribution of the coupling magnetic field, and configuring a resonant topology. Regarding adding energy coupling channels, existing technologies achieve stable system output power by adding energy coupling channels between the transmitting and receiving coils. For example, a single-transmitter-single-receiver magnetic coupling mechanism based on a relay coil mitigates output efficiency and power fluctuations after receiver offset. By employing four magnetic coupling mechanisms—single-transmitter-dual-receiver, dual-transmitter-single-receiver, and triple-transmitter-dual-receiver—the receiver power allocation strategy was optimized, improving the system's equivalent coupling coefficient and reducing leakage flux at offset positions. Adding an energy coupling channel allows for a wider range of transmitter excitation magnetic fields, effectively improving the magnetic coupling mechanism's anti-offset deflection characteristics. However, existing optimizations primarily focus on lateral and longitudinal anti-offset performance, failing to address anti-offset deflection performance in multiple directions. Regarding optimizing the spatial distribution of the coupling magnetic field, optimizing the size parameters of the coil and magnetic core, as well as the excitation method of the transmitter coil, can enhance the coupling mechanism's anti-offset capability, enabling the system to maintain stable mutual inductance when the receiver experiences offset deflection. For example, optimizing the external dimensions of the DD (Double-D, DD) ferrite magnetic guide mechanism and its placement relative to the coil reduces the magnetic reluctance in the mutual coupling region, resulting in a higher coupling coefficient. Existing technologies have also proposed FlatSolenoid Coupler (FSP) and Double-Solenoid Duadrature Pad (DSQP) mechanisms, analyzed the variation law of the coupling magnetic field distribution during the offset process, and optimized the size parameters of the transmitting and receiving coils and magnetic cores, thus achieving excellent anti-offset performance. These three types of coupling mechanisms improve the spatial distribution density of the magnetic field excited by the transmitting coil and optimize the path for the receiving coil to pick up magnetic flux, but they still do not simultaneously possess anti-offset and anti-deflection performance. Regarding resonant topology configuration, to achieve stable system output characteristics at the offset deflection position, existing technologies mainly employ two methods: ① adjusting the component parameters of the resonant topology; ② changing the topology form.Specifically, there are variable capacitors and variable inductors based on switch duty cycle control; and the influence of coupling mechanism offset on transmission power stability is overcome by utilizing the form conversion between third-order resonant topologies (LCC, LCL) and S-resonant topologies. However, due to the lack of analytical basis for wireless transmission systems, these methods are not suitable for rotating magnetic field coupling, resulting in poor anti-offset and deflection performance, requiring further optimization. In summary, there is a current need for a wireless transmission method and system that can adapt to rotating magnetic field coupling and has good anti-offset and anti-deflection performance. Summary of the Invention

[0003] The purpose of this invention is to provide a WPT anti-offset and anti-deflection method and system based on rotating magnetic field coupling, which can adapt to rotating magnetic field coupling and has good anti-offset and anti-deflection performance.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for resisting offset and deflection using a rotating magnetic field coupling (WPT) system includes: constructing a WPT system, wherein the WPT system employs two inverters to generate high-frequency voltages, which are supplied to a DQDD-CD coupling mechanism via an LCC-S resonant topology; applying orthogonal currents to the transmitting coil of the DQDD-CD coupling mechanism to cause the excitation magnetic field to rotate periodically; the DQDD-CD coupling mechanism picking up the excitation magnetic flux at a wide range of offset and deflection positions via a receiving coil; the two energy channels entering the rectifier circuit through compensation capacitors to ultimately provide power to the load; obtaining the component configuration parameters of the resonant circuit and the system transmission efficiency expression based on the WPT system; and obtaining the LCC-S resonant component configuration method with optimal offset and deflection resistance performance based on the component configuration parameters and the system transmission efficiency expression.

[0006] Applying orthogonal currents to the transmitting coil of the aforementioned DQDD-CD coupling mechanism causes the excitation magnetic field to rotate periodically. The aforementioned DQDD-CD coupling mechanism picks up the excitation magnetic flux through the receiving coil at a wide range of offset deflection positions, which is achieved as follows: the aforementioned transmitting coil consists of two pairs of decoupled DD coils arranged orthogonally in a double layer, and the aforementioned receiving coil consists of two sets of orthogonally placed flat dipole coils.

[0007] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission energy efficiency expression are obtained, including: establishing the effect law of three types of characteristic parameters of coupling mechanism winding, position and size on mutual inductance and coupling coefficient through the above system transmission energy efficiency expression, and giving the characteristic parameter values ​​of the transmitting and receiving mechanisms corresponding to the maximum expected value with the maximum coupling coefficient as the maximum expected value.

[0008] The aforementioned LCC-S resonant topology includes a primary-side compensation inductor, a primary-side parallel compensation capacitor, a primary-side series capacitor, a secondary-side series resonant capacitor, a transmitting coil self-inductance, and a receiving coil self-inductance. The output of any one of the aforementioned inverters is connected in series with the aforementioned primary-side compensation inductor and the aforementioned primary-side parallel compensation capacitor. The aforementioned primary-side parallel compensation capacitor is connected in parallel with the aforementioned primary-side series capacitor, the aforementioned transmitting coil self-inductance, and the series structure of the transmitting / receiving coil of the aforementioned DQDD-CD coupling mechanism. The aforementioned DQDD-CD coupling mechanism, the aforementioned receiving coil self-inductance, and the aforementioned secondary-side series resonant capacitor are connected in series with the input of one of the aforementioned rectifier circuits.

[0009] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transfer efficiency expression are obtained, including:

[0010] Assuming the excitation currents of the transmitting coils p1 and p2 have the same amplitude and a phase difference of α, the expressions for the inverter output currents I1 and I2 are:

[0011]

[0012] Since the transmitting coils p1 and p2 are orthogonal, the magnetomotive force f generated by the coils... DD1 f DD2 Represented as:

[0013]

[0014] In the formula, θ s Let ω be the angular frequency of the system, and let F be the reference space angle. Since the two sets of DD coils have the same structure and number of turns, F... DD1 =F DD2 Then the combined magnetomotive force f φ for:

[0015] f φ =f DD1 +f DD2 =F DD1 [cosωtcosθ s -cos(ωt+α)sinθ s (3);

[0016] When the phase difference between the excitation currents of the transmitting coils p1 and p2 is 90°, i.e., α = 90°, the resulting magnetomotive force is:

[0017] f φ =F DD1 cos(ωt-θ s (4);

[0018] According to equation (4), the combined magnetomotive force of the two pole magnetic fields is distributed in a periodic rotation with an angular frequency ω and the amplitudes are equal.

[0019] Optionally, obtaining the component configuration parameters of the resonant circuit and the system transfer efficiency expression based on the WPT system further includes:

[0020] Using the fundamental frequency approximation method, when the duty cycle of the two inverters is 50%, the two inverters generate high-frequency AC voltages U1 and U2 with a phase difference of 90°, expressed as:

[0021]

[0022] In the formula, U dc The input DC voltage for the two sets of inverters;

[0023] The KVL equations for the LCC-S resonant topology are as follows:

[0024]

[0025] In the formula, I p1 I p2 For the input current of the two channels, I S1 I S2 U is the output current of the two channels. pij U sij (i = 1, 2; j = 1, 2) represents the induced voltage generated by each mutual inductor in the DQDD-CD coupling mechanism, X Lfp1 X Lp1 X Ls1 To correspond to the inductive reactance of the resonant inductor, X Cfp1 X Cp1 X Cs1 X Cfp2 X Cp2 X Cs2 To correspond to the capacitive reactance of the resonant capacitor, R1 and R2 are the equivalent load resistances of the circuit containing the receiving coils s1 and s2, L p1 L p2 This corresponds to the self-inductance of the transmitting coil;

[0026] From formula (6):

[0027]

[0028] Among them, L fpi L represents the self-inductance of the i-th primary-side resonant inductor. pi L represents the self-inductance of the i-th transmitting coil. sj Let X represent the self-inductance of the j-th receiving coil. Lsj X represents the reactance of the receiving coil's self-inductance. Cpi C represents the capacitive reactance of the parallel resonant capacitor at the i-th emitter. fpi X represents the capacitance value of the parallel resonant capacitor at the i-th transmitter.Cpi C represents the capacitive reactance of the series resonant capacitor at the i-th emitter. pi C represents the capacitance of the series resonant capacitor at the i-th transmitter. sj This represents the capacitance value of the series resonant capacitor at the j-th receiver.

[0029] The LCC-S resonant element parameter configuration method is expressed as follows:

[0030]

[0031] From equations (6) to (8), the current in each loop is obtained:

[0032]

[0033] In the formula, Mp1s1 and Mp2s2 are the mutual inductances of the transmitting coils facing each other, Mp1s2 and Mp2s1 are the cross-coupled mutual inductances, and Mp1p2 and Ms1s2 are the mutual inductances of the coils coupled on the same side.

[0034] The equivalent load resistances R1 and R2 of the circuits containing receiving coils s1 and s2 are expressed as follows:

[0035]

[0036] In the formula, R eq This is the equivalent resistance of the circuit following the rectifier input.

[0037] Where A and B are intermediate variables, represented as follows:

[0038]

[0039] Combining equations (9), (10), and (11), we obtain the system output voltage U. o That is, resistive load R L Terminal voltage:

[0040]

[0041] The output power of the circuit containing the two sets of dipole coils is as follows:

[0042]

[0043] In the formula, r1 and r3 are the internal resistances of the transmitting coils p1 and p2, and r2 and r4 are the internal resistances of the receiving coils s1 and s2.

[0044] The total output power of the system is:

[0045]

[0046] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transfer efficiency expression are obtained, and the following are also included:

[0047] Combining equation (14), the system transmission efficiency expression is obtained as follows:

[0048]

[0049] The expressions for each intermediate variable are as follows:

[0050]

[0051] Based on equations (12) and (16), the input and output voltage gain G is derived. v The expression is:

[0052]

[0053] in:

[0054] In the formula, R L It is a resistive load.

[0055] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission efficiency expression are obtained. This also includes: under the condition that the coils at the transmitting and receiving terminals satisfy decoupling, the transmission performance of the dual-transmitter-dual-receiver coupling mechanism is expressed using an equivalent coupling coefficient k. eff describe:

[0056]

[0057] In the formula, Su s1 Su s2 VA represents the pickup capacity of the receiving coil. P1 VA P2 Indicates the transmission capacity of the transmitting coil; Vo c1 Vo c2 Is is the open-circuit voltage of the receiving coil. c1 Is c2 V is the short-circuit current of the receiving coil. p1 V p2 I is the terminal voltage of the transmitting coil. p1 I p2 Let Su be the excitation current of the transmitting coil; where Su is the capacity picked up by the receiving coil. s1 Su s2 and the transmission capacity VA of the transmitting coil P1 VA P2 Described by the mutual inductance model:

[0058]

[0059] Among them, due to the symmetrical parameters of the coils on the same side of the aforementioned DQDD-CD coupling mechanism, the self-inductance L of the transmitting coil is... p1 =L p2 The self-inductance of the receiving coil L s1 =L s2 By combining equations (19) and (20), we can derive:

[0060]

[0061] In the formula, M eff The equivalent mutual inductance of the coupling mechanism; according to K eff The coil and core dimensions of the transmitter and receiver are optimized to obtain the best anti-offset performance.

[0062] A WPT (Wide-Temperature Polarization) anti-offset and anti-deflection system based on rotating magnetic field coupling includes a WPT system and a component configuration analysis and optimization unit. The WPT system includes two inverters, an LCC-S resonant topology, a DQDD-CD coupling mechanism, and two rectifier circuits. The two inverters generate high-frequency voltages, which are supplied to the DQDD-CD coupling mechanism via the LCC-S resonant topology. The DQDD-CD coupling mechanism applies orthogonal currents to the transmitting coil to cause the excitation magnetic field to rotate periodically. The receiving coil picks up the excitation magnetic flux at a wide range of offset and deflection positions, and the flux is then fed into one of the rectifier circuits via compensation capacitors, ultimately providing power to the load. The component configuration analysis and optimization unit obtains the component configuration parameters of the resonant circuit and the system transmission efficiency expression based on the WPT system. Based on these parameters, it obtains the optimal LCC-S resonant component configuration method for anti-offset and deflection performance.

[0063] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0064] This application proposes a WPT (Wireless Transmission Platform) anti-offset and anti-deflection method and system based on rotating magnetic field coupling. The wireless transmission system constructs an LCC-S resonant topology based on a dual-inverter-dual-rectifier architecture. Orthogonal currents are applied to the DD (Diverter) transmitting coil to cause the excitation magnetic field to rotate periodically. The CD (Diverter) receiving coil can effectively pick up the excitation magnetic flux under a wide range of offset and deflection positions. The component configuration parameters of the resonant circuit and the system transmission energy efficiency expression are derived, and the optimal resonant circuit component configuration method for anti-offset and deflection performance is obtained based on the expression. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 This is a structural diagram of the rotating magnetic field coupled WPT system in Embodiment 1 of the present invention;

[0067] Figure 2 This is a schematic diagram of the DQDD-CD rotating magnetic field coupling mechanism in Embodiment 1 of the present invention;

[0068] Figure 3 This is a schematic diagram of the winding method of the DQDD coil in Embodiment 1 of the present invention;

[0069] Figure 4 This is a top view of the synthesized magnetic induction intensity in Embodiment 1 of the present invention;

[0070] Figure 5 This is a diagram showing the YOZ plane magnetic field distribution of the DQDD-CD coupling mechanism in Embodiment 1 of the present invention.

[0071] Figure 6 This is a schematic diagram of the LCC-S resonant topology in Embodiment 1 of the present invention;

[0072] Figure 7 The effect of the parameters to be optimized at the transmitter in Embodiment 1 of the present invention is as follows;

[0073] Figure 8 The effect of the parameters to be optimized at the receiving end in Embodiment 1 of the present invention is shown. Detailed Implementation

[0074] Example 1

[0075] Please see Figures 1 to 8 , Figures 1 to 8The diagram shows a schematic of a WPT anti-offset and anti-deflection method and system based on rotating magnetic field coupling provided in an embodiment of this application. The WPT anti-offset and anti-deflection method based on rotating magnetic field coupling includes: constructing a WPT system, wherein the WPT system uses two inverters to generate high-frequency voltages, which are supplied to a DQDD-CD coupling mechanism through an LCC-S resonant topology; applying orthogonal currents to the transmitting coil of the DQDD-CD coupling mechanism to cause the excitation magnetic field to rotate periodically; the DQDD-CD coupling mechanism picks up the excitation magnetic flux through a receiving coil at a wide range of offset and deflection positions; the two energy channels respectively enter the rectifier circuit through compensation capacitors, ultimately providing power to the load; obtaining the component configuration parameters of the resonant circuit and the system transmission efficiency expression based on the WPT system; and obtaining the LCC-S resonant component configuration method with optimal anti-offset and deflection performance based on the component configuration parameters and the system transmission efficiency expression.

[0076] Applying orthogonal currents to the transmitting coil of the aforementioned DQDD-CD coupling mechanism causes the excitation magnetic field to rotate periodically. The aforementioned DQDD-CD coupling mechanism picks up the excitation magnetic flux through the receiving coil at a wide range of offset deflection positions, which is achieved as follows: the aforementioned transmitting coil consists of two pairs of decoupled DD coils arranged orthogonally in a double layer, and the aforementioned receiving coil consists of two sets of orthogonally placed flat dipole coils.

[0077] The system's transmitting mechanism employs a double-layer quadrature DD (DQDD) coil, while the receiving mechanism uses a crossed dipole (CD) coil. The DQDD transmitting coil consists of two pairs of decoupled DD coils arranged orthogonally in a double layer, while the CD receiving coil consists of two sets of orthogonally placed flat dipole coils. Figure 2 (a) is the DQDD-CD rotating magnetic field coupling mechanism proposed in this embodiment. The transmitting end DQDD coil consists of two sets of orthogonally stacked DD coils and a square magnetic core, wherein each D coil is the same size; the receiving end CD coil consists of two sets of orthogonally stacked dipole coils and a magnetic core, wherein each flat helical coil is the same size, and a square shielding aluminum plate is placed at the bottom of the transmitting end and the top of the receiving end. Figure 2 (b) gives the stacking order of the magnetic coupling mechanisms.

[0078] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission energy efficiency expression are obtained, including: establishing the effect law of three types of characteristic parameters of coupling mechanism winding, position and size on mutual inductance and coupling coefficient through the above system transmission energy efficiency expression, and giving the characteristic parameter values ​​of the transmitting and receiving mechanisms corresponding to the maximum expected value with the maximum coupling coefficient as the maximum expected value.

[0079] Figure 3(a) describes the winding method of the DQDD coil. The winding directions of the D coils on both sides of the same layer are opposite, and their start and end points are connected to each other; the CD coil of the receiving mechanism uses a cross-shaped magnetic strip to wind two sets of dipole coils, which are composed of two flat helical coils wound in the same direction in series, such as... Figure 3 As shown in (b), the orthogonal placement of the two DD coils in the DQDD transmitting coil and the reverse winding of the coaxial D coils on the same layer are to achieve mutual decoupling of the two DD coils. Because the magnetic flux excited by one DD coil and entering the other DD coil is approximately equal to the corresponding outgoing component, the net coupling magnetic flux between the two sets of DD coils is close to zero. Furthermore, the induced voltage generated by the remaining net magnetic flux in the coaxial D coils cancels each other out, further weakening the coupling between the two DD coils. Secondly, the mutual decoupling of the two DD coils means that the excitation currents of the two coils do not affect each other, thus enabling independent control, thereby reducing the computational complexity of the compensation components and the control complexity of the system output. The orthogonal placement and reverse winding of the DQDD transmitting coil allow it to obtain a rotating magnetic field within the coupling space. The flat window of the receiving CD coil is used to fully pick up the horizontal component of the coupled magnetic field, and the coaxial, same-direction series winding enables the superposition of the picked-up magnetic flux induced electromotive force. The CD coil is not wound into the intersection area of ​​the cross-shaped magnetic guide mechanism in order to provide a magnetic guide path in the event of offset deflection, thereby ensuring a high retention rate of the picked-up magnetic flux.

[0080] The dimensions of each component of the DQDD-CD coupling mechanism affect its resistance to deflection. Specifically, the coaxial DD coil spacing d1 and core length W3 of the transmitting mechanism determine the coverage area of ​​the rotating magnetic field; the core thickness of the magnetic guiding mechanism determines the penetrating magnetic flux density; and the core length and coil winding length of the receiving mechanism affect the pickup range of the coupled magnetic field. Furthermore, the optimized parameters of the coupling mechanism must also consider weight, volume, available finished products, and overall cost. Referring to the relevant standards GB / T 38775 and IEC 61980 for electric vehicle WPT systems, the following dimensional parameters of the transmitting mechanism's DQDD coil are set: W5 = 300mm, W7 = 150mm, d2 = 130mm. The Litz wire diameter h3 = 3mm, and the number of coil turns N = 19, therefore W6 = 186mm, W8 = 36mm. The DQDD coil W2 = 300mm + d1; the aluminum plate size W1 = W2 + 70mm. As shown below, the first and second columns of Table 1 give the dimensional parameters and optimization range of the magnetic coupling mechanism to be optimized.

[0081] Table 1

[0082]

[0083] The above LCC-S resonant topology includes the primary-side compensating inductor L fp1 Lfp2 Primary-side parallel compensation capacitor, primary-side series capacitor C fp1 C fp2 Secondary-side series resonant capacitor C s1 C s2 The self-inductance of the transmitting coil L p1 L p2 The self-inductance of the receiving coil L s1 L s2 The output of any one of the above inverters is connected in series with the primary-side compensation inductor and the primary-side parallel compensation capacitor; the primary-side parallel compensation capacitor is connected in parallel with the primary-side series capacitor, the self-inductance of the transmitting coil, and the series structure of the transmitting / receiving coil of the DQDD-CD coupling mechanism; the DQDD-CD coupling mechanism, the self-inductance of the receiving coil, the secondary-side series resonant capacitor, and the input of one of the above rectifier circuits are connected in series.

[0084] like Figure 1 The diagram shown is a structural diagram of a rotating magnetic field coupled WPT system. Figure 1 Parts I to IV represent two sets of parallel full-bridge inverters, an LCC-S resonant topology, a DQDD-CD magnetic coupling mechanism, and two sets of series rectifier and filter circuits, respectively. This system utilizes two independent high-frequency inverters to generate high-frequency AC voltages U1 and U2 with a 90° phase difference. These voltages are supplied to the transmitting coil of the DQDD-CD coupling mechanism via the LCC resonant topology. The receiving coil picks up the energy using the generated rotating magnetic field, and the energy then passes through a compensation capacitor into the rectifier circuit, ultimately providing power to the load. In the DQDD-CD magnetic coupling mechanism, M... p1s1 M p2s2 For the transmitting coil to be directly opposite the mutual inductance, M p1s2 M p2s1 For cross-coupled mutual inductance, M p1p2 M s1s2 For mutual inductance of coils on the same side, U oi I si For the output voltage and current of the two channels, C o1 C o2 For the filter capacitor of the rectifier circuit, U o For the equivalent resistive load R L The terminal voltage.

[0085] In order to make the excitation current of the DQDD transmitting coil independent of the relative position of the pickup mechanism, and at the same time to ensure that the output voltage is not affected by the equivalent resistance of the load, an LCC-S resonant topology was established for the DQDD-CD coupling mechanism. Figure 6 For the sake of simplifying the analysis, the parasitic resistance of the inductor and capacitor is omitted in the LCC-S resonant circuit with the equivalent mutual inductance model of the DQDD-CD coupling mechanism.

[0086] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission efficiency expression are obtained, including: assuming that the excitation currents of the above transmitting coils p1 and p2 have the same amplitude and a phase difference of α, then the expressions for the inverter output currents I1 and I2 are:

[0087]

[0088] Since the transmitting coils p1 and p2 are orthogonal, the magnetomotive force f generated by the coils... DD1 f DD2 Represented as:

[0089]

[0090] In the formula, θ s Let ω be the angular frequency of the system, and let F be the reference space angle. Since the two sets of DD coils have the same structure and number of turns, F... DD1 =F DD2 Then the combined magnetomotive force f φ for:

[0091]

[0092] When the phase difference between the excitation currents of the aforementioned transmitting coils p1 and p2 is 90°, i.e., α = 90°, the resulting magnetomotive force is:

[0093] f φ =F DD1 cos(ωt-θ s (4);

[0094] From equation (4), the combined magnetomotive force of the two pole magnetic fields exhibits a periodic rotating distribution with an angular frequency ω, and the amplitudes are equal. Therefore, the magnetic induction intensity B excited by the DQDD transmitting coil in the coupling space also has rotational characteristics. The top view of the combined magnetic induction intensity is shown below. Figure 4 As shown.

[0095] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission efficiency expression are obtained. The analysis also includes: using the fundamental frequency approximation method, when the duty cycle of the two inverters is 50%, the two inverters generate high-frequency AC voltages U1 and U2 with a phase difference of 90°, expressed as:

[0096]

[0097] In the formula, U dc Let be the input DC voltage of the two inverters; the KVL equations for the LCC-S resonant topology are as follows:

[0098]

[0099] From formula (6):

[0100]

[0101] The LCC-S resonant element parameter configuration method is expressed as follows:

[0102]

[0103] From equations (6) to (8), the current in each loop is obtained:

[0104]

[0105] In the formula, Mp1s1 and Mp2s2 are the mutual inductances of the transmitting coils facing each other, Mp1s2 and Mp2s1 are the cross-coupled mutual inductances, and Mp1p2 and Ms1s2 are the mutual inductances of the coils coupled on the same side; the equivalent load resistances R1 and R2 of the circuit containing the receiving coils s1 and s2 are expressed as:

[0106]

[0107] Where A and B are represented as:

[0108]

[0109] Combining equations (9), (10), and (11), we obtain the system output voltage U. o That is, the terminal voltage of the resistive load RL:

[0110]

[0111] The output power of the circuit containing the two sets of dipole coils is as follows:

[0112]

[0113] The total output power of the system is:

[0114]

[0115] Due to the high impedance of the LCC resonant topology to harmonics, the fundamental frequency approximation method was used in the analysis of the system transmission characteristics. As shown in equation (9), when the operating frequency remains constant, the excitation currents of the two transmitting coils are only related to U. dc and L fpi The circuit is independent of the load and mutual inductance, achieving independent control of the two excitation currents. If L fp1 =L fp2 Then the amplitudes of the two paths are equal, and the phase difference of the excitation current is always 90°, which satisfies the excitation current condition required by the coupling mechanism. From equations (5) and (9), it can be seen that the input impedance of the circuit is purely resistive, therefore the input reactive power is zero. The power consumed by R1 and R2 is equal to that consumed by R... LThe power consumed is the same, thus yielding equation (10). From equation (12), it can be seen that the output voltage U0 is the same as the load R. L It is irrelevant, but depends on U. dc L fp1 The relative positions of the transmitting and receiving coils. Further considering the influence of coil internal resistance on transmission power, let r1 and r3 be the internal resistances of transmitting coils p1 and p2, and r2 and r4 be the internal resistances of receiving coils s1 and s2. From this, the output power of the circuit containing the two sets of dipole coils can be obtained. As can be seen from equation (15), maximizing transmission efficiency means that ρ0 has a lower limit. That is, the internal resistance r2 of the receiving coil should be as close as possible to the transmitting coil r1; after the transmitting and receiving coils are wound, the transmission efficiency η depends on the load R. L According to equation (15), the optimal load R corresponding to the maximum efficiency can be derived. L From equation (17), it can be seen that the voltage gain G v The voltage gain is inversely proportional to Q0, which means that in applications requiring high voltage gain, Q0 should be configured to be as small as possible.

[0116] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission efficiency expression are obtained, and further: combining equation (14), the system transmission efficiency expression is obtained as follows:

[0117]

[0118] in:

[0119]

[0120] Based on equations (12) and (16), the input and output voltage gain G is derived. v The expression is:

[0121]

[0122] in:

[0123] Based on the above WPT system, the component configuration parameters of the resonant circuit and the system transmission efficiency expression are obtained. This also includes: under the condition that the coils at the transmitting and receiving terminals satisfy decoupling, the transmission performance of the dual-transmitter-dual-receiver coupling mechanism is expressed using an equivalent coupling coefficient k. eff describe:

[0124]

[0125] In the formula, Su s1 Su s2 VA represents the pickup capacity of the receiving coil. P1 VA P2 Indicates the transmission capacity of the transmitting coil; Vo c1Vo c2 Is is the open-circuit voltage of the receiving coil. c1 Is c2 V is the short-circuit current of the receiving coil. p1 V p2 I is the terminal voltage of the transmitting coil. p1 I p2 Let Su be the excitation current of the transmitting coil; where Su is the capacity picked up by the receiving coil. s1 Su s2 and the transmission capacity VA of the transmitting coil P1 VA P2 Described by the mutual inductance model:

[0126]

[0127] Among them, due to the symmetrical parameters of the coils on the same side of the aforementioned DQDD-CD coupling mechanism, the self-inductance L of the transmitting coil is... p1 =L p2 The self-inductance of the receiving coil L s1 =L s2 By combining equations (19) and (20), we can derive:

[0128]

[0129] In the formula, M eff The equivalent mutual inductance of the coupling mechanism; according to K eff The coil and core dimensions of the transmitter and receiver are optimized to obtain the best anti-offset performance.

[0130] The power transfer capability of the coupling mechanism in a WPT system is commonly evaluated by the value of the coupling coefficient k. Among coupling mechanisms of the same size and different types, a larger k value indicates better power transfer performance. Under the condition that the transmitting and receiving terminal coils are decoupled, the transmission performance of a "dual-transmitter-dual-receiver" coupling mechanism can be expressed using the equivalent coupling coefficient K. eff To describe it. In equation (21), K eff The simulation values ​​can be obtained through finite element analysis tools, and the coil and core size parameters of the transmitter and receiver can be optimized accordingly to obtain the optimal anti-offset performance.

[0131] like Figure 5 The diagram shows the YOZ plane magnetic field distribution of the DQDD-CD coupling mechanism. Under fixed excitation magnetomotive force conditions, when the offset of the receiving mechanism is within W3 / 5, the flatly distributed coupling magnetic field and the flatly wound coaxial dipole receiving coil allow the picked-up magnetic flux to maintain a high density within the W3 / 5 offset range, such as... Figure 5 (a) When the receiving mechanism is offset outside the W3 / 5 range, the pickup magnetic flux density of the D coil on the right side of the receiving mechanism decreases, such as Figure 5 (b) At this point, the intersection area of ​​the cross-shaped magnetic guiding mechanism provides the main coupling path, thereby shortening the coupling magnetic circuit. As a result, the magnetic flux density picked up by the D coil on the left side of the receiving mechanism increases, and the complementary effect of the magnetic flux picked up by the D coils on both sides slows down the attenuation rate of the picked-up magnetic flux. When the receiving mechanism is deflected, the rotational distribution characteristics of the coupling magnetic field and the orthogonal winding method of the CD coil of the receiving mechanism enable the picked-up magnetic flux to be maintained at a high density at any deflection angle.

[0132] During the experiment, Figure 7 The figure shows the effect of the parameters to be optimized at the transmitter, where Figure 7 (a) The curves showing the relationship between the spacing d1 of the coaxial DD coils at the transmitting end and the self-inductance, mutual inductance, and equivalent coupling coefficient of the transmitting and receiving coils are presented. As can be seen from the figure, with the increase of d1, the self-inductance L of the transmitting coil... pi The self-inductance L of the receiving coil has been decreasing. sj After fluctuating by ±5μH, it gradually stabilized; mutual inductance M p1s1 M p2s2 With K eff The curve shows a "rise then fall" trend, with the inflection point at d1 = 28.6%. To achieve better power transmission performance and a smaller coil terminal voltage in the coupling mechanism, the coaxial DD coil spacing d1 = 28.6%, i.e., d1 = 120 mm, is selected.

[0133] Figure 8 The diagram shows the interaction principle of the parameters to be optimized at the receiving end. Figure 8 (a) It can be seen that as the core length W 12 With the increase of K eff The curve shows a trend of first increasing and then slowly decreasing, when the core length W 12 The normalized value is 95.23%, K eff It reached a maximum of 0.146. (By...) Figure 8 (b) It can be seen that as the width W4 of the magnetic core cross-section increases, K eff It first increases rapidly and then levels off. When the normalized value of the core length W4 is 23.1%, K... eff It reached a maximum of 0.147. (By...) Figure 8 (c) It can be seen that as h4 increases, K eff The curve flattens out. (Combined) Figure 8 As shown in (b) and (c), as the cross-sectional area of ​​the receiving end magnetic core increases, K... eff It will tend to stabilize. Figure 8 (d) It can be seen that K eff With W 10 The increase is due to the linear relationship between the picked-up magnetic flux and the coil length. Figure 8 Core size and Keff Considering the relationship between the ferrite core length W and the compactness, weight, and cost of the vehicle-mounted receiver mechanism, the length W of the ferrite core was selected accordingly. 12 =390mm, cross-sectional width W4=90mm, thickness h4=10mm, coil length W 10 =142mm.

[0134] The above experimental results can be verified by building a 500W experimental prototype with a transmission spacing of 130mm, within a horizontal offset range of 50% (±150mm) and a vertical deflection range of 0° to 90°, to assess the anti-offset deflection performance and system transmission energy efficiency of the DQDD-CD magnetic coupling mechanism. Taking into account the optimization results, the overall dimensional parameters of the coupling mechanism are listed in Table 2. The parameters used will serve as the basis for subsequent anti-offset deflection performance analysis and experimental verification.

[0135] Table 2

[0136]

[0137] Example 2

[0138] This application provides a WPT (Wide-Temperature Detection and Offset) anti-deflection system based on rotating magnetic field coupling, comprising a WPT system and a component configuration analysis and optimization unit. The WPT system includes two inverters, an LCC-S resonant topology, a DQDD-CD coupling mechanism, and two rectifier circuits. The two inverters generate high-frequency voltages, which are supplied to the DQDD-CD coupling mechanism via the LCC-S resonant topology. The DQDD-CD coupling mechanism applies orthogonal currents to the transmitting coil to cause the excitation magnetic field to rotate periodically, and picks up the excitation magnetic flux at a wide range of offset deflection positions via the receiving coil. The flux then passes through compensation capacitors and enters one of the rectifier circuits, ultimately providing power to the load. The component configuration analysis and optimization unit obtains the component configuration parameters of the resonant circuit and the system transmission efficiency expression based on the WPT system, and obtains the optimal LCC-S resonant component configuration method for anti-offset deflection performance based on the component configuration parameters and the system transmission efficiency expression.

[0139] The principle of this embodiment is the same as that of Embodiment 1, and there is no need to repeat the description here. The WPT anti-offset and anti-deflection system based on rotating magnetic field coupling can have more or fewer components, and each component can be implemented by hardware, software or a combination thereof.

[0140] In summary, this application provides a WPT anti-offset and anti-deflection method and system based on rotating magnetic field coupling: by applying orthogonal currents to the DQDD transmitting coil, the excitation magnetic field rotates periodically, allowing the CD receiving coil to fully pick up the excitation magnetic flux under a wide range of offset deflection positions. Furthermore, the effects of three types of characteristic parameters—winding, position, and size of the coupling mechanism—on mutual inductance and coupling coefficient are established, and the characteristic parameter values ​​of the transmitting and receiving mechanisms corresponding to the maximum expected value of the maximum coupling coefficient are given. The variation laws of mutual inductance and coupling coefficient of the DQDD-CD coupling mechanism under offset deflection positions are analyzed, an LCC-S resonant topology based on a dual-inverter-dual-rectifier is constructed, and the component configuration parameters of the resonant circuit and the system transmission energy efficiency expression are derived.

[0141] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling, characterized in that, include, A WPT system is constructed, which uses two inverters to generate high-frequency voltages and supplies them to a DQDD-CD coupling mechanism through an LCC-S resonant topology. Orthogonal currents are applied to the transmitting coil of the DQDD-CD coupling mechanism to cause the excitation magnetic field to rotate periodically. The DQDD-CD coupling mechanism picks up the excitation magnetic flux through its receiving coil at a wide range of deflection positions. The two energy channels pass through compensation capacitors and enter the rectifier circuit, ultimately providing power to the load. Based on the WPT system, the component configuration parameters of the resonant circuit and the system transmission energy efficiency expression are obtained. Based on the component configuration parameters and the system transmission energy efficiency expression, the LCC-S resonant component configuration method with the best anti-offset deflection performance is obtained. An orthogonal current is applied to the transmitting coil of the DQDD-CD coupling mechanism to make the excitation magnetic field rotate periodically. The DQDD-CD coupling mechanism picks up the excitation magnetic flux through the receiving coil at a wide range of offset deflection positions. This is achieved by the following: the transmitting coil consists of two pairs of decoupled DD coils arranged orthogonally in a double layer, and the receiving coil consists of two sets of orthogonally placed flat dipole coils.

2. The WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling as described in claim 1, characterized in that, Based on the WPT system, the component configuration parameters of the resonant circuit and the system transmission energy efficiency expression are obtained, including: establishing the effect law of three types of characteristic parameters of coupling mechanism winding, position and size on mutual inductance and coupling coefficient through the system transmission energy efficiency expression, and giving the characteristic parameter values ​​of the transmitting and receiving mechanisms corresponding to the maximum expected value with the maximum coupling coefficient as the maximum expected value.

3. The WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling as described in claim 1, characterized in that, The LCC-S resonant topology includes a primary-side compensation inductor, a primary-side parallel compensation capacitor, a primary-side series capacitor, a secondary-side series resonant capacitor, a transmitting coil self-inductance, and a receiving coil self-inductance. The output of any one of the inverters is connected in series with the primary-side compensation inductor and the primary-side parallel compensation capacitor. The primary-side parallel compensation capacitor is connected in parallel with the primary-side series capacitor, the transmitting coil self-inductance, and the series connection of the transmitting / receiving coil of the DQDD-CD coupling mechanism. The DQDD-CD coupling mechanism, the receiving coil self-inductance, and the secondary-side series resonant capacitor are connected in series with the input of one of the rectifier circuits.

4. The WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling as described in claim 1, characterized in that, Based on the WPT system, the component configuration parameters of the resonant circuit and the system transfer efficiency expression are obtained, including: Assuming the excitation currents of the transmitting coils p1 and p2 have the same amplitude and a phase difference of α, then the inverter output current... , The expression is: （1）； Since the transmitting coils p1 and p2 are orthogonal, the magnetomotive force generated by the coils... , Represented as: （2）； In the formula, Let ω be the reference space angle and ω be the angular frequency of the system; where the two sets of DD coils have the same structure and number of turns, therefore = Then the combined magnetomotive force for: （3）； When the phase difference between the excitation currents of the transmitting coils p1 and p2 is 90°, i.e., α = 90°, the resulting magnetomotive force is: （4）； According to equation (4), the combined magnetomotive force of the two pole magnetic fields is distributed in a periodic rotation with an angular frequency ω and the amplitudes are equal.

5. The WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling as described in claim 4, characterized in that, Based on the WPT system, the component configuration parameters of the resonant circuit and the system transfer efficiency expression are obtained, and the system further includes: Using the fundamental frequency approximation method, when the duty cycle of the two inverters is 50%, the two inverters generate high-frequency AC voltages with a 90° phase difference. , , is represented as: （5）； In the formula, The input DC voltage for the two sets of inverters; The KVL equations for the LCC-S resonant topology are as follows: （6）； In the formula, , For the input current of two channels, , The output current of the two channels, , The induced voltages generated by each mutual inductor in the DQDD-CD coupling mechanism are i=1,2; j=1,2; , , To correspond to the inductive reactance of the resonant inductor, , , , , , This is the capacitive reactance of the corresponding resonant capacitor. , The equivalent load resistance of the circuit containing receiving coils s1 and s2 is given. , This corresponds to the self-inductance of the transmitting coil; From formula (6): （7）； in, fpi This represents the self-inductance of the i-th primary-side resonant inductor. pi This represents the self-inductance of the i-th transmitting coil. sj This represents the self-inductance of the j-th receiving coil. Lsj The reactance representing the self-inductance of the receiving coil. Cpi This represents the capacitive reactance of the parallel resonant capacitor at the i-th emitter. fpi This represents the capacitance value of the parallel resonant capacitor at the i-th transmitter. Cpi This represents the capacitive reactance of the series resonant capacitor at the i-th emitter. pi This represents the capacitance value of the series resonant capacitor at the i-th transmitter. sj This represents the capacitance value of the series resonant capacitor at the j-th receiver. The LCC-S resonant element parameter configuration method is expressed as follows: （8）； From equations (6) to (8), the current in each loop is obtained: （9）； In the formula, p1s1、 p2s2 is the mutual inductance between the transmitting coil and the receiving coil. p1s2, p2s1 is a cross-coupled mutual inductance. p1p2, s1 and s2 are the mutual inductance of coils coupled on the same side; The equivalent load resistance of the circuit containing receiving coils s1 and s2 , Represented as: （10）； In the formula, This is the equivalent resistance of the circuit following the rectifier input. Where A and B are intermediate variables, represented as follows: （11）； The system output voltage is obtained by combining equations (9), (10) and (11). o That is, resistive load L Terminal voltage: （12）； The output power of the circuit containing the two sets of dipole coils is as follows: （13）； In the formula, , For transmitting coil , internal resistance, , For receiving coil , The internal resistance; The total output power of the system is: （14）。 6. The WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling as described in claim 5, characterized in that, Based on the WPT system, the component configuration parameters of the resonant circuit and the system transfer efficiency expression are obtained, and the system further includes: Combining equation (14), the system transmission efficiency expression is obtained as follows: （15）； The expressions for each intermediate variable are as follows: （16）； Based on equations (12) and (16), the input and output voltage gain G is derived. v The expression is: （17）； in: (18); In the formula, It is a resistive load.

7. The WPT anti-deflection and anti-rotation method based on rotating magnetic field coupling as described in claim 6, characterized in that, Based on the WPT system, the component configuration parameters of the resonant circuit and the system transfer efficiency expression are obtained, and the system further includes: Under the condition that the coils at the transmitting and receiving terminals are decoupled, the transmission performance of the dual-transmitter-dual-receiver coupling mechanism is achieved using the equivalent coupling coefficient. describe: （19）； In the formula, , This indicates the pickup capacity of the receiving coil. , Indicates the transmission capacity of the transmitting coil; , The open-circuit voltage of the receiving coil. , For the short-circuit current of the receiving coil, , This is the terminal voltage of the transmitting coil. , This is the excitation current of the transmitting coil; Among them, the capacity picked up by the receiving coil , and the transmission capacity of the transmitting coil , Described by the mutual inductance model: （20）； In this context, due to the symmetrical parameters of the coils on the same side of the DQDD-CD coupling mechanism, the self-inductance of the transmitting coil... = The self-inductance of the receiving coil = ; The following is derived from the combined equations (19) and (20): （21）； In the formula, The equivalent mutual inductance of the coupling mechanism; according to The coil and core dimensions of the transmitter and receiver are optimized to obtain the best anti-offset performance.

8. A WPT anti-deflection and anti-rotation system based on rotating magnetic field coupling, characterized in that, Includes the WPT system and component configuration analysis and optimization unit; The WPT system includes two inverters, an LCC-S resonant topology, a DQDD-CD coupling mechanism, and two rectifier circuits. The two inverters are used to generate high-frequency voltages respectively, and supply them to the DQDD-CD coupling mechanism through the LCC-S resonant topology; The DQDD-CD coupling mechanism is used to apply orthogonal currents to the transmitting coil to make the excitation magnetic field rotate periodically, and to pick up the excitation magnetic flux through the receiving coil at a wide range of offset deflection positions. Then, the magnetic flux is fed into one of the rectifier circuits through compensation capacitors, and finally provides power to the load. The transmitting coil consists of two pairs of decoupled DD coils arranged orthogonally in a double layer, and the receiving coil consists of two sets of orthogonally placed flat dipole coils. The component configuration analysis and optimization unit obtains the component configuration parameters of the resonant circuit and the system transmission energy efficiency expression based on the WPT system, and obtains the LCC-S resonant component configuration method with optimal anti-offset deflection performance based on the component configuration parameters and the system transmission energy efficiency expression.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method as described in any one of claims 1-7.

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