A omnidirectional and all-attitude wireless power supply system and control method thereof

Abstract

The present application provides an omnidirectional and all-posture wireless power supply system and a control method thereof. The system includes a transmitting end and a receiving end, characterized in that the transmitting end includes three concentrically arranged and mutually orthogonal transmitting coils, each transmitting coil is respectively connected to a wireless charging transmitting circuit, and the receiving end includes three concentrically arranged and mutually orthogonal receiving coils, each receiving coil is respectively connected to a wireless charging receiving circuit and then supplies power to the load in parallel. The effect is that no matter how the load posture changes, the receiving coil and the transmitting coil will not be completely orthogonal, ensuring that the load can transmit energy with maximum efficiency in all postures. When the system is controlled, the load position can be judged according to the current changes of each transmitting coil, and then the phase shift parameters of the transmitting mutual inductance coil are changed by the controller to adjust the current size, so that its electromagnetic vector is always aligned with the receiving coil to complete the omnidirectional load with maximum efficiency wireless power supply.

Description

Technical Field

[0001] The present application relates to wireless power transmission technology, and in particular to an omnidirectional and all-posture wireless power supply system and a control method thereof. Background Art

[0002] With the continuous development of wireless power transmission (WPT) technology, wireless charging has injected new vitality into the fields of electric transportation, robots, medical implants, etc. However, the existing mainstream WPT system mainly uses a single receiving coil to power the load. This power supply method requires that the receiving coil and the transmitting coil are in a tangent state to meet the maximum transmission efficiency, and the transmission efficiency will be reduced due to changes in the load posture. Therefore, the current mainstream WPT system has certain limitations, which are mainly manifested in high requirements for load posture, high requirements for transmitter performance, low power transmission efficiency, and inconsistent power supply in different directions. Most existing electronic devices have high portability and freedom, and the traditional mainstream WPT system can no longer meet market demand.

[0003] In order to improve the flexibility of wireless charging, some researchers use radio frequency technology to generate a uniform magnetic field in the WPT system to provide power to multiple receiving coils at the same time, but this requires expensive radio frequency power amplifiers. Some researchers have also proposed multiple dipole receiving coils, allowing the device to be charged freely at any position on a two-dimensional plane. However, these methods are not suitable for devices that move and rotate in three-dimensional space. Summary of the invention

[0004] In view of this, the present invention first provides an omnidirectional and all-posture wireless power supply system to improve the convenience and flexibility of the existing wireless power supply system.

[0005] In order to achieve the above object, the specific technical solutions adopted by the present invention are as follows:

[0006] A omnidirectional and all-posture wireless power supply system includes a transmitting end and a receiving end. The key is that the transmitting end includes three concentrically arranged and mutually orthogonal transmitting coils, each transmitting coil is respectively connected to a wireless charging transmitting circuit, and the receiving end includes three concentrically arranged and mutually orthogonal receiving coils, each receiving coil is respectively connected to a wireless charging receiving circuit and then supplies power to a load through a grid-connected circuit.

[0007] Optionally, the transmitting coil and the receiving coil are wound in the same manner, the coils with the same turn are wound in an arc shape, two adjacent turns of the coils are connected by a radially arranged transition section, three transmitting coils and three receiving coils are staggered using their respective inter-turn gaps, and the internal resistance of each transmitting coil is the same.

[0008] Optionally, the transmitting coil and the receiving coil are wound with excitation wires and fixed by a 3D printed acrylic bracket.

[0009] Optionally, the wireless charging transmitting circuit includes a direct current power supply, a high-frequency inverter and a primary resonance compensation circuit, and the wireless charging receiving circuit includes a secondary resonance compensation circuit and a rectifier and filter circuit.

[0010] Optionally, both the primary resonance compensation circuit and the secondary resonance compensation circuit adopt a resonant capacitor series compensation structure.

[0011] Optionally, the high-frequency inverters of the three wireless charging transmitting circuits share a DC power supply.

[0012] Optionally, the high-frequency inverters of the three wireless charging transmitting circuits are full-bridge inverter circuits and are respectively connected to the controller. The controller is configured with three groups of current sensors and voltage sensors. Each group of current sensors and voltage sensors detects the working current and working voltage of a transmitting coil. The controller controls the PWM phase shift angle of the corresponding high-frequency inverter according to the working current and working voltage of each transmitting coil.

[0013] Based on the above system, the present invention also provides a control method for an omnidirectional and all-attitude wireless power supply system, the key of which is that the high-frequency inverters in the three wireless charging transmitting circuits are controlled according to the following steps:

[0014] S1: Set the PWM wave phase shift angle of each high-frequency inverter in the three wireless charging transmitting circuits to be initialized to 0, and measure the RMS value U of the AC voltage source output by the wireless charging transmitting circuit 0 and the system internal resistance R 0 ;

[0015] S2: Monitor the initial current of the three transmitting coils of the three wireless charging transmitting circuits, recorded as I 1 ,I 2 ,I 3 And determine whether the respective initial currents have changed, if the change exceeds the preset threshold, proceed to step S3, otherwise continue monitoring;

[0016] S3: Obtain the current values ​​of the three transmitting coils after they are relatively stable and record them as At the same time, calculate the current change value of each and record it as ΔI 1 , ΔI 2 , ΔI 3 ;

[0017] S4: According to and Calculate the intermediate variable m 1 、m 2 、m 3and M B The value of; where: ΔI is ΔI 1 , ΔI 2 , ΔI 3 The maximum value in ;

[0018] S5: Follow Calculate load space position parameters and θ;

[0019] S6: Follow Calculate the desired PWM wave offset phase angle, where the calculation method of each intermediate variable is:

[0020]

[0021] Among them, sgn() is the symbol function;

[0022] S7: Desired PWM wave offset phase angle calculated in step S6 The high-frequency inverters in the three wireless charging transmitting circuits are controlled respectively, and the process returns to step S2 to repeat the process in a loop.

[0023] Optionally, in step S2, whether the respective initial currents have changed is determined based on whether the current change exceeds 5% of the initial current.

[0024] Optionally, the high-frequency inverters in the three wireless charging transmitting circuits implement full-dimensional and full-posture maximum transmission efficiency tracking control of the load through the controller executing steps S1 to S7.

[0025] Optionally, the present invention further provides a control method for an omnidirectional and all-attitude wireless power supply system, wherein the high-frequency inverters in the three wireless charging transmitting circuits are controlled according to the following steps:

[0026] S11: Set working state 1, the three transmitting coils work independently, when one transmitting coil is working, the other two transmitting coils remain disconnected, and measure the corresponding working current of each transmitting coil when it is working. And the working current of the three receiving coils and receiving voltage j=a,b,c, corresponding to the three receiving coils a, b, c, i=1,2,3 corresponding to the three transmitting coils, the superscript 1 indicates the system working state 1, That is, the working current of the i-th transmitting coil in the system working state 1, That is, the working current of the jth receiving coil when the i-th transmitting coil works independently in the system working state 1, That is, the working voltage of the jth receiving coil when the i-th transmitting coil works independently in the system working state 1;

[0027] S12: According to Calculate the mutual inductance M between a single receiving coil and a transmitting coil ij ; where ω is the resonant angular frequency, R a , R b , R c Respectively represent the equivalent resistance of the receiving end circuit in the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c; Respectively represent the load equivalent resistance in the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c; X a , X b , X c They represent the equivalent reactance of the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c respectively;

[0028] S13: Call the math tool according to:

[0029]

[0030] Solving function Load space position parameters when taking the maximum value and the value of θ;

[0031] S14: According to Calculate the optimal current of each transmitting coil when the power is maximum, where the current amplitude U 0 is the AC equivalent voltage output by the high-frequency inverter, V DC is the DC input voltage in the three wireless charging transmitting circuits, R 0 is the equivalent resistance of each wireless charging transmitting circuit;

[0032] S15: Follow Calculate the optimal current of each receiving coil when the power is maximum;

[0033] S16: Follow Calculate the PWM wave offset phase angle expected by each transmitting coil when the power is maximum; where R 1 , R 2 , R 3 Respectively represent the equivalent resistance of the three transmitting coils 1, 2, and 3; R s1 , R s2 , R s3 Respectively represent the equivalent power supply internal resistance in the wireless charging transmitting circuit corresponding to the three transmitting coils 1, 2, and 3;

[0034] S17: The controller calculates the desired PWM wave offset phase angle according to step S16 The high-frequency inverters in the three wireless charging transmitting circuits are controlled separately to achieve maximum transmission power control.

[0035] The remarkable effects of the present invention are:

[0036] The present application provides an omnidirectional and all-posture wireless power supply system and its control method. The system consists of three groups of mutually orthogonal transmitting coils and corresponding circuits inside a spherical space. Since the receiving end is also provided with three groups of mutually orthogonal receiving coils inside the spherical space, the receiving coils and the transmitting coils will not be completely orthogonal regardless of how the load posture changes. This structure improves the wireless power supply efficiency of the WPT system and ensures that the load can ensure the maximum efficiency of energy transmission in all postures. When the system is controlled, the position of the transmitting and receiving coils in space can be determined according to the current changes of each transmitting coil, and then the phase shift parameters of the transmitting mutual inductance coil can be changed by the controller to adjust the current of the transmitting coil so that its electromagnetic vector is always aligned with the receiving coil to complete the omnidirectional load with maximum efficiency wireless power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0038] Figure 1 is a topological diagram of the system circuit structure in the specific embodiment 1 of the present invention;

[0039] Figure 2 is a schematic diagram of a system circuit in a specific embodiment 1 of the present invention;

[0040] Figure 3 Schematic diagram of the winding form of the generating coil in the specific embodiment 1 of the present invention;

[0041] Figure 4 It is a principle block diagram of the system control circuit in the specific embodiment 1 of the present invention;

[0042] Figure 5 This is a system control flow chart in specific embodiment 1 of the present invention;

[0043] Figure 6 is a topological diagram of the system circuit structure in specific embodiment 2 of the present invention;

[0044] Figure 7 is a schematic diagram of a system circuit in a specific embodiment 2 of the present invention;

[0045] Figure 8 This is a system control flow chart in specific embodiment 2 of the present invention. DETAILED DESCRIPTION

[0046] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0047] Embodiment 1:

[0048] like Figure 1 As shown, for powering independent devices in a space environment, the low gravity environment in space may cause problems such as flipping and turning of the equipment. If the traditional wire connection method is used for power supply at this time, it is likely to cause problems such as wire knotting and entanglement, which may lead to safety accidents. If a wireless power supply system is used, power supply and safety can be guaranteed at the same time. Therefore, this embodiment provides an all-round and all-attitude wireless power supply system, including a transmitting end and a receiving end, the transmitting end includes three concentrically arranged and mutually orthogonal transmitting coils (also called transmitting mutual inductance coils), each transmitting coil is respectively connected to a wireless charging transmitting circuit, and the receiving end includes three concentrically arranged and mutually orthogonal receiving coils (also called receiving mutual inductance coils), each receiving coil is respectively connected to a wireless charging receiving circuit and then supplies power to the load through a grid-connected circuit. Combined with Figure 2 It can be seen that in the specific implementation, the wireless charging transmitting circuit includes a DC power supply, a high-frequency inverter and a primary-side resonance compensation circuit, and the wireless charging receiving circuit includes a secondary-side resonance compensation circuit and a rectifier filter circuit. In this example, the high-frequency inverters of the three wireless charging transmitting circuits can share a DC power supply, which can be converted into an AC voltage source through the high-frequency inverter circuit respectively. The primary-side resonance compensation circuit and the secondary-side resonance compensation circuit both adopt a resonant capacitor series compensation structure.

[0049] As for the rectifier filter circuit, since the current received in the receiving coil is an alternating current, it needs to be rectified to convert it into a direct current to supply the load. The rectifier circuit is a capacitor filter circuit. The alternating current first passes through the rectifier bridge to become a direct current with a large ripple, and then is filtered through a parallel resistor to finally obtain a relatively smooth direct current, thereby achieving the purpose of filtering. The equivalent circuit of the receiving coil is three current sources plus a rectifier circuit, and then the three receiving circuits are loaded to the two ends of the load respectively, thereby achieving the purpose of integrating the current.

[0050] The transmitting end of the system is composed of three sets of mutually orthogonal transmitting coils in a spherical space and corresponding wireless energy transmitting circuits. Since the receiving coil is also composed of three sets of mutually orthogonal receiving coils in a spherical space and corresponding wireless energy receiving circuits, the receiving coil and the transmitting coil will not be completely orthogonal regardless of how the load posture changes. This structure effectively improves the wireless power supply efficiency of the WPT system and ensures that the load can ensure the most efficient energy transmission in all postures. The system can determine the position of the receiving coil in space based on the change in the current of the transmitting coil, and then automatically adjust the current of the transmitting mutual inductance coil through the controller so that the electromagnetic vector of the transmitting coil is always aligned with the receiving mutual inductance coil to complete the full load power supply.

[0051] The transmitting coil and the receiving coil have the same structure but different sizes. In order to ensure that each turn of the transmitting coil is a standard circle, the invention adopts a new winding method, such as Figure 3 As shown, the coil with the same turn is wound in an arc shape, and the adjacent two turns of the coil are connected by a radially arranged transition section. The three transmitting coils and the three receiving coils are staggered using their respective inter-turn gaps, and the internal resistance of each transmitting coil is the same. This winding method can ensure that the coils can be completely aligned to a certain extent, thereby improving the transmission efficiency. Secondly, in order to maximize the transmission efficiency, the power supply wire is composed of 300 copper wires, with an inner radius of 100mm, a turn distance of 10mm, 10 turns per coil, and a total coil diameter of 40cm. In specific implementation, the transmitting coil and the receiving coil are wound with excitation wires and fixed by a 3D printed acrylic bracket. The three coils are cross-combined in a pairwise orthogonal manner. In actual situations, this combination method can ensure that no matter how the posture of the receiving load changes, the transmitting coil and the receiving coil will always have two opposite faces to ensure the wireless power supply efficiency. This winding method can minimize the change of the magnetic field caused by the change of curvature. The overall spherical receiving system can ensure that it can receive a considerable magnetic field in all postures, thereby ensuring its power under all posture conditions.

[0052] Combination Figure 4 It can be seen that the high-frequency inverters of the three wireless charging transmitting circuits are full-bridge inverter circuits and are respectively connected to the controller. The controller is configured with three groups of current sensors and voltage sensors. Each group of current sensors and voltage sensors detects the working current and working voltage of a transmitting coil. The controller controls the PWM phase shift angle of the corresponding high-frequency inverter according to the working current and working voltage of each transmitting coil.

[0053] When the actual system is working, as the circuit working time increases, the circuit will generate heat, which will cause the corresponding resonant frequency to change. Therefore, it is necessary to adjust the frequency of the alternating current generated by the FPGA.

[0054] The feedback system can automatically adjust the transmission frequency so that the system can work stably at the resonant frequency. The core of the system is to use STM32 to detect current changes at all times. If the current change (i.e. ΔI / Δt) does not exceed the set threshold, it means that the load coordinates in three-dimensional space have changed. This is the load space coordinate change stage. The system automatically completes the coordinate calculation and performs three-dimensional power supply.

[0055] If the current change exceeds the set threshold, it means that the load coil is stable. The current change at this time is caused by the increase in temperature, which leads to temperature drift. At this time, STM32 is working in the "fine-tuning working" state. STM32 will send a control signal to the FPGA chip. The FPGA chip adjusts the transmission current parameters to change the frequency of the current, which can ensure that the receiving load receives the maximum power. When the current change returns to the set threshold, it indicates that the current temperature drift adjustment is over, and the system returns to the load space coordinate change stage.

[0056] In actual situations, by detecting the ADC port of the STM32H750VBT6 microcontroller and setting the threshold range, it is possible to detect whether the system drifts due to temperature. When the microcontroller detects temperature drift, it can automatically change the algorithm to adjust the output current to achieve the effect of suppressing temperature drift.

[0057] In addition, this embodiment also provides a control method for an omnidirectional and all-attitude wireless power supply system, such as Figure 5 As shown, the high-frequency inverters in the three wireless charging transmitting circuits are controlled according to the following steps:

[0058] S1: Set the PWM wave phase shift angle of each high-frequency inverter in the three wireless charging transmitting circuits to be initialized to 0, and measure the RMS value U of the AC voltage source output by the wireless charging transmitting circuit 0 and the system internal resistance R 0 ;

[0059] S2: Monitor the initial current of the three transmitting coils of the three wireless charging transmitting circuits, recorded as I 1 ,I 2 ,I 3 And determine whether the respective initial currents have changed, if the change exceeds the preset threshold, proceed to step S3, otherwise continue monitoring;

[0060] S3: Obtain the current values ​​of the three transmitting coils after they are relatively stable and record them as At the same time, calculate the current change value of each and record it as ΔI 1 , ΔI 2 , ΔI 3 ;

[0061] S4: According to and Calculate the intermediate variable m 1 、m 2 、m 3 and M B The value of; where: ΔI is ΔI 1 , ΔI 2 , ΔI 3 The maximum value in ;

[0062] S5: Follow Calculate load space position parameters and θ;

[0063] S6: Follow Calculate the desired PWM wave offset phase angle, where the calculation method of each intermediate variable is:

[0064]

[0065] Among them, sgn() is the symbol function;

[0066] S7: Desired PWM wave offset phase angle calculated in step S6 The high-frequency inverters in the three wireless charging transmitting circuits are controlled respectively, and the process returns to step S2 to repeat the process in a loop.

[0067] In specific implementation, in step S2, it is determined whether the initial current has changed according to whether the current change exceeds 5% of the initial current. The high-frequency inverters in the three wireless charging transmission circuits implement the load full-range and full-stance maximum transmission efficiency tracking control through the controller executing steps S1-S7.

[0068] In order to better understand the design concept of the present invention, a more detailed theoretical explanation is given below:

[0069] Combination Figure 1 It can be seen that since the system is composed of three transmitting coils and three receiving coils, in order to simplify the theoretical derivation process, we will regard the system composed of three receiving coils as a whole below, first analyze the receiving coil as a whole and finally analyze the receiving coil independently.

[0070] According to the mutual inductance coupling theory, we abstract the system and label the transmitting coils as 1, 2, and 3 respectively. The circuit equation in the transmitting coil circuit can be expressed by (1), and the equivalent voltage source can be expressed by equation (2):

[0071]

[0072] In equation (1), X i (i=1,2,3) is the reactance in the transmitting coil, I i is the current in the loop, Ri is the load resistance, and ω is the angular frequency of the AC voltage source. ja is the mutual inductance between the transmitting coil j and the receiving coil a, R sj is the source resistance, U j is the voltage source in equation (2) (j = 1, 2, 3), U in equation (2) 0 is the RMS value of the AC voltage source, β 1 , β 2 , β 3 is the phase angle of the corresponding excitation source. By adjusting the full-bridge inverter, the size of β can be adjusted to change the direction of the magnetic field vector of the three transmitting coils, so that the direction of wireless power supply always points to the load. Since the three transmitting coils in the system are orthogonal to each other, the mutual inductance between the three transmitting coils is theoretically zero and can be ignored in actual situations. When we use a full-bridge inverter as the power supply of the system, the system source resistance can be ignored, and the current of the transmitting coil can be adjusted by adjusting the phase shift control of the inverter by adjusting the PWM wave.

[0073] In the WPT system, a full-bridge inverter is used as the transmitting source of the system. Since the source resistance is too small, it can be ignored in actual situations. The current of the transmission coil can be adjusted through the phase shift control of the inverter.

[0074]

[0075] To maximize the power transfer capability, the transmitting coil should be operated in resonant mode. The system is tuned to resonant mode by adjusting the values ​​of the system resistance, inductance, and capacitance. The three current values ​​in the circuit in resonant mode are shown in equation (4):

[0076]

[0077] In equation (4), A=M 1a u 1 +M 2a u 2 +M 3a u 3 ,

[0078] M ia (i=1,2,3) is the mutual inductance of the three transmitting coils to the receiving coil, R′ a It is the total equivalent resistance value of the receiving device circuit.

[0079] In order to achieve maximum efficiency transmission, maximum power transmission and true omnidirectional power transmission, the current transmission vector direction can be controlled by controlling the corresponding angle according to equation (5), and the specific angle can be adjusted by equation (6). In actual situations, the angle change needs to be determined according to the actual measurement situation.

[0080]

[0081] Where m in equation (6) i (i=1,2,3) is defined as equation (7)

[0082]

[0083] Among them, m 1 is the mutual inductance ratio, ΔI i =I i -I 0 |ΔI|=max{|ΔI I |},|ΔM 0 |=max{|ΔM ia |}

[0084] Define parameter α add for:

[0085]

[0086] According to equation (4) and equation (5), we can get: The corresponding phase shift angle that needs to be adjusted This corresponds to the following equation:

[0087]

[0088] Based on the above calculations, we can convert the relationship between the deflection angle and current in the wireless charging system into:

[0089]

[0090] In summary, by adjusting the value of the deflection angle α of each inverter, the current I of the transmitting coil can be changed, thereby achieving all-round and all-posture wireless charging.

[0091] Embodiment 2:

[0092] The deep-sea environment has difficult factors such as complex water pressure, corrosive seawater and low temperature. Conventional wired charging methods face risks such as cable wear, connection difficulties and potential leakage, especially when seabed operations are frequent. In order to solve these problems, this omnidirectional wireless power transmission system is used to charge unmanned underwater vehicles (UUVs). The system can achieve omnidirectional wireless power transmission without precise alignment, thereby improving the charging efficiency and safety of the submersible.

[0093] like Figure 6 and Figure 7 As shown, this embodiment provides an all-round and all-attitude wireless power supply system. Compared with Embodiment 1, the main difference in the control circuit is that each transmitting coil is provided with a switching switch, and the working state of each transmitting coil can be changed by switching the switch. When specifically controlling, Figure 8 As shown:

[0094] A control method for an omnidirectional and all-stance wireless power supply system, wherein high-frequency inverters in three wireless charging transmitting circuits are controlled according to the following steps:

[0095] S11: Set working state 1, the three transmitting coils work independently, when one transmitting coil is working, the other two transmitting coils remain disconnected, and measure the corresponding working current of each transmitting coil when it is working. And the working current of the three receiving coils and receiving voltage j=a,b,c, corresponding to the three receiving coils a, b, c, i=1,2,3 corresponding to the three transmitting coils, the superscript 1 indicates the system working state 1, That is, the working current of the i-th transmitting coil in the system working state 1, That is, the working current of the jth receiving coil when the i-th transmitting coil works independently in the system working state 1, That is, the working voltage of the jth receiving coil when the i-th transmitting coil works independently in the system working state 1;

[0096] S12: According to Calculate the mutual inductance M between a single receiving coil and a transmitting coil ij ; where ω is the resonant angular frequency, R a , R b , R c Respectively represent the equivalent resistance of the receiving end circuit in the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c (including the internal resistance of the receiving coil); Respectively represent the load equivalent resistance in the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c; X a , X b , X cRespectively represent the equivalent reactance of the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c;

[0097] During implementation:

[0098] When coil 1 works alone, according to the mutual inductance coupling theory, we can get:

[0099]

[0100] When coil 2 works alone, according to the mutual inductance coupling theory, we can get:

[0101]

[0102] When coil 3 works alone, according to the mutual inductance coupling theory, it can be obtained that:

[0103]

[0104] Therefore, the various mutual inductance calculation formulas mentioned above can be obtained by simplification.

[0105] S13: Call the math tool according to:

[0106]

[0107] Solving function Load space position parameters when taking the maximum value and the value of θ; in the specific implementation, mathematical solving software such as MATLAB, Python, Mathematica, Maple, etc. can be used to solve the maximum value of the equation.

[0108] S14: According to Calculate the optimal current of each transmitting coil when the power is maximum, where the current amplitude U 0 is the AC equivalent voltage output by the high-frequency inverter, V DC is the DC input voltage in the three wireless charging transmitter circuits, R 0 is the equivalent resistance of each wireless charging transmitting circuit;

[0109] S15: Follow Calculate the optimal current of each receiving coil when the power is maximum;

[0110] S16: Follow Calculate the PWM wave offset phase angle expected by each transmitting coil when the power is maximum; where R 1 , R 2 , R 3 Respectively represent the equivalent resistance of the three transmitting coils 1, 2, and 3; R s1 , R s2 , Rs3 Respectively represent the equivalent power supply internal resistance in the wireless charging transmitting circuit corresponding to the three transmitting coils 1, 2, and 3;

[0111] S17: The controller calculates the desired PWM wave offset phase angle according to step S16 The high-frequency inverters in the three wireless charging transmitting circuits are controlled separately to achieve maximum transmission power control.

[0112] During the control process, the current in the transmitting coil can be detected periodically or continuously. When the newly calculated α exceeds the set threshold range, it means that the position has changed. Return to the first step to readjust the phase shift angle, thereby achieving maximum transmission power tracking control.

[0113] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0114] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A control method for an omnidirectional and all-attitude wireless power supply system, the system comprises a transmitting end and a receiving end, the transmitting end comprises three concentrically arranged and mutually orthogonal transmitting coils, each transmitting coil is respectively connected to a wireless charging transmitting circuit, the receiving end comprises three concentrically arranged and mutually orthogonal receiving coils, each receiving coil is respectively connected to a wireless charging receiving circuit and then supplies power to a load through a grid-connected circuit; the wireless charging transmitting circuit comprises a DC power supply, a high-frequency inverter and a primary resonance compensation circuit, characterized in that: The high-frequency inverters in the three wireless charging transmission circuits are controlled according to the following steps: S11: Set working state 1, the three transmitting coils work independently, when one transmitting coil is working, the other two transmitting coils remain disconnected, and measure the corresponding working current of each transmitting coil when it is working. And the working current of the three receiving coils and receiving voltage The corresponding three receiving coils are a, b, and c, and i=1, 2, and 3 correspond to the three transmitting coils. The superscript 1 indicates the system working state 1. That is, the working current of the i-th transmitting coil in the system working state 1, That is, the working current of the jth receiving coil when the i-th transmitting coil works independently in the system working state 1, That is, the working voltage of the jth receiving coil when the i-th transmitting coil works independently in the system working state 1; S12: According to Calculate the mutual inductance M between a single receiving coil and a transmitting coil ij ; where ω is the resonant angular frequency, R a , R b , R c Respectively represent the equivalent resistance of the receiving end circuit in the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c; Respectively represent the load equivalent resistance in the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c; X a , X b , X c Respectively represent the equivalent reactance of the wireless charging receiving circuit corresponding to the three receiving coils a, b, and c; S13: Call the math tool according to: Solving function Load space position parameters when taking the maximum value and the value of θ; S14: According to Calculate the optimal current of each transmitting coil when the power is maximum, where the current amplitude U0 is the AC equivalent voltage output by the high-frequency inverter, V DC is the DC input voltage in the three wireless charging transmitting circuits, and R0 is the equivalent resistance of each wireless charging transmitting circuit; S15: Follow Calculate the optimal current of each receiving coil when the power is maximum; S16: Follow Calculate the PWM wave offset phase angle expected by each transmitting coil when the power is maximum; R1, R2, and R3 represent the equivalent resistances of the three transmitting coils 1, 2, and 3 respectively; R s1 , R s2 , R s3 Respectively represent the equivalent power supply internal resistance in the wireless charging transmitting circuit corresponding to the three transmitting coils 1, 2, and 3; S17: The controller calculates the desired PWM wave offset phase angle according to step S16 The high-frequency inverters in the three wireless charging transmitting circuits are controlled separately to achieve maximum transmission power control.

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