Asymmetric coupling variable coil type bidirectional wireless electric energy transmission system, method and equipment

Abstract

The invention relates to the technical field of wireless electric energy transmission, in particular to an asymmetric coupling variable coil type bidirectional wireless electric energy transmission system, method and equipment, the system comprises a power grid side unit and a load side unit, the power grid side unit comprises a primary side direct current power supply, a primary side inverter, a variable primary side compensation network and a primary side coil assembly, the first coil and the second coil are connected in series; a primary side controller; the load side unit comprises a secondary side direct-current power supply, a secondary side switch network, a variable secondary side compensation network and a connection secondary side switch network; a secondary coil; the secondary side controller is used for adjusting the conduction state of the secondary side switching network; according to the asymmetric coupling structure of the primary side coil assembly and the secondary side coil, wireless bidirectional constant current or wireless bidirectional constant voltage transmission of electric energy is carried out. According to the invention, the problems of insufficient bidirectional control capability, rigid structure and hardware redundancy caused by dependence on a complex control link and a symmetrical structure of the existing bidirectional wireless power transmission system are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power transmission, and in particular to an asymmetric coupling variable coil type bidirectional wireless power transmission system, method and device. Background Art

[0002] Bidirectional wireless power transmission technology realizes the bidirectional wireless flow of electric energy through magnetic coupling. It is the core technology for realizing dynamic energy management in the fields of electric vehicles, smart grids, etc. It requires the switching requirements of constant current (CC) charging and constant voltage (CV) floating charging of the battery to be met during forward transmission (power supply from the grid to the load), and supports constant current discharge and constant voltage stabilization functions during reverse transmission (power supply from the load to the grid).

[0003] However, traditional variable frequency control relies on frequency regulation to achieve output mode switching, but frequency deviation can easily lead to system detuning, efficiency drop, and slow dynamic response; DC-DC auxiliary control adjusts the output through an additional power converter, which has high accuracy, but the additional devices increase the system volume, loss and cost; although phase shift modulation can adjust the output through phase difference, it requires complex algorithm support and the switching loss increases significantly with phase deviation. In addition, most solutions in the existing technology only optimize unidirectional transmission (such as forward charging), and the constant current and voltage control capabilities are weak during reverse transmission, resulting in asymmetric bidirectional performance; the system design strictly relies on the symmetry of the primary and secondary coils and the compensation network, and it is difficult to adapt to asymmetric scenarios such as the size difference between vehicles and power grid equipment; in order to achieve mode switching, multiple sets of primary controllers or switching devices need to be configured, which has high hardware complexity and reduced reliability.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] The present invention provides an asymmetric coupled variable coil type bidirectional wireless power transmission system, method and device, which can effectively solve the problems in the background technology.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: An asymmetric coupled variable coil bidirectional wireless power transmission system, the system comprising a grid side unit and a load side unit, wherein: The grid side unit includes a primary DC power supply U dc1 ; A primary inverter, including switch tubes Q1 and Q2, connected to the primary DC power supply; a variable primary compensation network, connected to the primary inverter; a primary coil assembly, consisting of a first coil L p1 and the second coil L p2A primary side controller is configured to switch the connection state of the variable primary side compensation network; The load side unit includes a secondary DC power supply U dc2 ; A secondary switch network, including switch tubes Q3, Q4, Q5, Q6, connected to the secondary DC power supply; a variable secondary compensation network, connected to the secondary switch network; a secondary coil L s ; A secondary side controller, adjusting the conduction state of the secondary side switch network; According to the primary coil assembly and the secondary coil L s The asymmetric coupling structure is used to perform wireless bidirectional constant current or wireless bidirectional constant voltage transmission of electric energy.

[0007] Furthermore, in the primary coil assembly, the first coil L p1 is a toroidal coil, the second coil L p2 It is a double D-type coil; The first coil is arranged around the second coil, and a ferrite isolation layer is arranged between the two; The secondary coil L s is a ring coil, wound on the ferrite substrate, and connected with the first coil L p1 Arranged vertically in space.

[0008] Furthermore, the variable primary compensation network includes a series compensation inductor L1, a parallel compensation capacitor C1, a first series compensation capacitor C p1 , the second series compensation capacitor C p2 And the primary side controller S; The switching end of the primary controller S is connected between the output end of the primary inverter and the series compensation inductor L1; The other end of the series compensation inductor L1 is connected to one end of the parallel compensation capacitor C1 and the second series compensation capacitor C p2 one end of The second series compensation capacitor C p2 The other end is connected to the second coil L p2 ; The first series compensation capacitor C p1 One end of the primary side controller S is connected to the primary side inverter output end, and the other end is connected to the first coil L p1 .

[0009] Furthermore, the variable secondary compensation network includes a series compensation inductor L2, a parallel compensation capacitor C2, and a series compensation capacitor C s and the secondary side switch network; One end of the series compensation inductor L2 is connected to the secondary DC power supply U through the switch tube Q6.dc2 The negative electrode of the capacitor C2 is connected to one end of the parallel compensation capacitor C2 and the series compensation capacitor C s one end of The other end of the parallel compensation capacitor C2 is connected to the node between the switch tube Q4 and the switch tube Q5; The series compensation capacitor C s The other end is connected to the secondary coil L s one end of The secondary coil L s The other end is connected to the node between the switch tube Q5 and the switch tube Q6.

[0010] Furthermore, the primary side controller and the secondary side controller are further configured to include: In the constant current output mode, the primary side controller S is controlled to disconnect the first coil L p1 A connection node a is connected to a node b and the switch tubes Q4 and Q6 in the secondary switch network are constantly turned on, so that the variable secondary compensation network forms an LCC topology; In the constant voltage output mode, the primary side controller S is controlled to connect to the connection node a and to the first coil L. p1 , and the switch tube Q3 in the secondary side switch network is constantly turned on, and the switch tube Q6 is constantly turned off, so that the variable secondary side compensation network forms an S-type topology.

[0011] Furthermore, when the bidirectional transmission mode is executed, it includes: During forward transmission, the primary inverter operates in a high-frequency inversion state, and the secondary switch network operates as a half-wave rectifier; During reverse transmission, the secondary side switch network is switched to a half-bridge inverter state, and the primary side inverter operates as a half-wave rectifier.

[0012] Furthermore, the parameters of the variable primary compensation network and the variable secondary compensation network should satisfy the following resonance conditions: ; ; ; ; ; Where, ω is the operating angular frequency of the system, L1 is the series compensation inductor, C1 is the parallel compensation capacitor, L2 is the series compensation inductor, C2 is the parallel compensation capacitor, L s is the secondary coil, C s is the series compensation capacitor, L p1 For the first coil, C p1is the first series compensation capacitor, L p2 For the second coil, C p2 is the second series compensation capacitor.

[0013] Furthermore, the system provides a constant current independent of the load in a constant current output mode and provides a constant voltage independent of the load in a constant voltage output mode through coordinated switching of the asymmetric coupling structure and the variable compensation network.

[0014] An asymmetric coupled variable coil bidirectional wireless power transmission method, the method comprising: Collect the two-end power parameters of the output and input ends in real time, and analyze and obtain the regulation requirements; According to the regulation requirements, physical switching of the primary side controller contacts and logical reconstruction of the secondary side switch tube network are controlled to generate a multi-dimensional control framework; Based on the two-terminal electric energy parameters of the variable primary compensation network and the variable secondary compensation network, a bidirectional zero phase difference resonance condition is established; According to the multi-dimensional control framework and the spatial orthogonal layout of the first coil and the second coil, a mutual inductance adjustment channel of the primary and secondary coils is constructed to maintain a bidirectional transmission path while eliminating redundant coupling; Based on the synergistic effect of the multi-dimensional control framework and the bidirectional zero phase difference resonance condition, load-independent constant current or constant voltage output is achieved in a bidirectional transmission scenario through the current source characteristics of the LCC topology and the voltage source characteristics of the SS topology.

[0015] An asymmetric coupling variable coil type bidirectional wireless power transmission device is used to realize the asymmetric coupling variable coil type bidirectional wireless power transmission system.

[0016] The technical solution of the present invention can achieve the following technical effects: Through the coordinated control of the mechanical primary controller and the semiconductor switch, the primary coil and secondary switch network functions are reused to reduce hardware complexity. By utilizing dynamic parameter matching and frequency closed-loop tracking, zero phase difference resonance is maintained under the asymmetric structure to ensure efficient energy transmission within the full load range, thus solving the problems of insufficient two-way control capability, structural rigidity and hardware redundancy.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 The circuit diagram of an asymmetrically coupled variable coil bidirectional wireless power transmission system is shown; Figure 2 A coupling mechanism structure diagram of an asymmetric coupling variable coil type bidirectional wireless power transmission system; Figure 3 This is the circuit schematic diagram in the forward and reverse constant current output mode; Figure 4 It is the equivalent circuit diagram in the forward and reverse constant current output mode; Figure 5 This is the circuit schematic diagram in the forward and reverse constant voltage output mode; Figure 6 It is the equivalent circuit diagram in the forward and reverse constant voltage output mode; Figure 7 The present invention is a working flow chart of an asymmetric coupled variable coil type bidirectional wireless power transmission system. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0022] Embodiment 1; like Figure 1 As shown, the present application provides an asymmetric coupled variable coil bidirectional wireless power transmission system, the system includes a grid side unit and a load side unit, wherein: Grid side unit, including primary DC power supply U dc1 ; The primary inverter includes switch tubes Q1 and Q2, connected to the primary DC power supply; a variable primary compensation network, connected to the primary inverter; a primary coil assembly, consisting of a first coil L p1 and the second coil L p2Series structure; primary side controller, switching the connection state of the variable primary side compensation network; Load side unit, including secondary DC power supply U dc2 ; A secondary switch network, including switch tubes Q3, Q4, Q5, Q6, connected to a secondary DC power supply; a variable secondary compensation network, connected to the secondary switch network; a secondary coil L s ; A secondary side controller, regulating the conduction state of the secondary side switch network; According to the primary coil assembly and the secondary coil L s The asymmetric coupling structure is used to perform wireless bidirectional constant current or wireless bidirectional constant voltage transmission of electric energy.

[0023] Specifically, in the forward constant current output or constant voltage output mode, the primary side controller controls the relay to form a dual-coil structure for the coupling transformer, and the secondary side controller switches the secondary side compensation network to the LCC compensation topology (constant current mode) or the SS compensation topology (constant voltage mode); in the reverse constant current output or constant voltage output mode, the primary side controller controls the transformer to be a dual-coil structure or a three-coil structure by switching the relay, and the secondary side controller controls the secondary side switch tube network to be a half-bridge inverter to ensure efficient feedback of electric energy; the relay control is used to switch different coupling structures (dual coils or three coils) to achieve constant current or constant voltage output according to load requirements; the secondary side controller switches the secondary side compensation network according to the working mode to form LCC or SS compensation topologies respectively to ensure the stability of the output current or voltage; in the constant current mode, the relay is controlled to disconnect or connect different nodes, and the secondary side controller controls the switch tubes Q4 and Q6 to be constantly turned on, and switches the secondary side compensation network to the LCC topology (composed of the series compensation inductor L2, the parallel compensation capacitor C2 and the series compensation capacitor C s In constant voltage mode, the control relay switches the first coil L p1 Connected to the required node, the secondary side controller makes the switch tube Q3 always on, the switch tube Q6 always off, and the secondary side compensation network switches to SS topology (with series compensation capacitor C s and the secondary coil L s composition) to achieve constant voltage output.

[0024] Through the technical solution of the present invention, seamless control of bidirectional constant current and constant voltage output under an asymmetric structure is achieved, and the hardware complexity is reduced by multiplexing the primary coil and the secondary switch network functions. Dynamic parameter matching and frequency closed-loop tracking are used to maintain zero phase difference resonance under the asymmetric structure to ensure efficient energy transmission within the full load range, thereby solving the problems of insufficient bidirectional control capability, structural rigidity and hardware redundancy.

[0025] Further, if Figure 2 As shown, in the primary coil assembly, the first coil L p1 is a toroidal coil, the second coil Lp2 It is a double D-type coil; The first coil is arranged around the second coil, and a ferrite isolation layer is arranged between the two; Secondary coil L s It is a ring coil, wound on the ferrite matrix, and connected with the first coil L p1 Arranged vertically in space.

[0026] As a preferred embodiment of the above, the first coil is an annular structure, usually wound with copper wire, circular or elliptical, and placed in the core area of ​​the primary side. The annular design enables the first coil to form a uniform magnetic field during transmission and enhance the electromagnetic coupling efficiency. The specific size, number of turns and wire diameter of the coil are optimized according to the system design requirements to ensure effective coupling with the second coil while maximizing the transmission efficiency; the second coil adopts a double D-type structure, that is, two D-shaped coils are symmetrically arranged to enhance the asymmetry of the coupling. The advantage of this design is that it can provide more flexible and efficient electromagnetic coupling, especially suitable for bidirectional power transmission. The double D-type structure forms a special electromagnetic field distribution in space, which is suitable for multi-mode operation and can better support constant current and constant voltage output modes. A ferrite isolation layer is placed between the first coil and the second coil. The ferrite material has excellent magnetic permeability and high magnetic permeability, which can effectively isolate the mutual influence between the coils, reduce the interference of the magnetic field, and improve the coupling efficiency. The thickness and shape of the isolation layer will be optimized according to the design requirements to achieve the ideal electromagnetic shielding effect and ensure efficient energy transmission. The secondary coil is a toroidal coil, similar to the first coil, usually wound with copper wire and designed as a ring. The coil is wound on The ferrite matrix enhances the magnetic field focusing ability of the coil and improves the power receiving ability. The secondary coil and the first coil are arranged vertically in space. This vertical layout can avoid unnecessary interference in electromagnetic coupling and help optimize energy transmission efficiency. The relative position of the secondary coil and the primary coil can be fine-tuned according to the specific needs of the system to achieve the best transmission performance; during the forward power transmission process of the system, the primary inverter drives the first coil and the second coil to generate a strong alternating magnetic field, and the secondary coil receives this magnetic field and converts it into electrical energy. Due to the double D-type design of the primary coil component and the ferrite The use of the isolation layer and electromagnetic coupling can effectively reduce the dispersion of the magnetic field and improve the energy transmission efficiency of the system; during the reverse transmission process, the secondary coil and the first coil continue to maintain a good magnetic coupling relationship, and the secondary coil transmits energy in reverse to the primary coil assembly. At this time, the vertical arrangement of the secondary coil and the first coil can effectively improve the energy conversion efficiency; the primary coil and the second coil are arranged according to the design requirements, and ensure that the ferrite isolation layer is installed between the two to reduce electromagnetic interference; in the secondary part, the secondary coil is wound on the ferrite substrate, and ensure that it is arranged vertically in space with the first coil to maximize the coupling efficiency.

[0027] Furthermore, the variable primary compensation network includes a series compensation inductor L1, a parallel compensation capacitor C1, a first series compensation capacitor C p1 , the second series compensation capacitor C p2 and the primary side controller S; The switching end of the primary controller S is connected between the output end of the primary inverter and the series compensation inductor L1; The other end of the series compensation inductor L1 is connected to one end of the parallel compensation capacitor C1 and the second series compensation capacitor C p2 one end of The second series compensation capacitor C p2 The other end is connected to the second coil L p2 ; The first series compensation capacitor C p1 One end is connected to the primary inverter output through the switching of the primary controller S, and the other end is connected to the first coil L p1 .

[0028] As a preferred embodiment of the above, in the variable primary compensation network, the series compensation inductor L1 is located in the primary circuit and is connected in series between the output end of the primary inverter and other compensation elements. Its main function is to adjust the current phase, reduce voltage fluctuations, and enhance the stability of the system; the parallel compensation capacitor C1 is connected in parallel with the series compensation inductor L1 to stabilize the voltage and reduce current fluctuations. This capacitor is used to balance the voltage drop caused by the inductor to ensure the stability of the output voltage; the first series compensation capacitor C p1 With the second series compensation capacitor C p2 In series in the network, C p1 Its function is to stabilize the output voltage of the primary inverter, C p2 Then with the primary coil L p2 The primary controller S is a control unit responsible for adjusting the working state of the components in the primary compensation network. It can switch different capacitors and inductors according to load requirements and working modes to optimize the power transmission efficiency of the system. The switching end of the primary controller S is connected between the output end of the primary inverter and the series compensation inductor L1. The current and voltage of the system are adjusted by controlling the connection mode of the capacitor and the inductor to ensure that the system can achieve constant current or constant voltage output in different working modes. The switching end of the primary controller S is connected between the output end of the primary inverter and the series compensation inductor L1. It controls the current flow direction and voltage change of the series compensation inductor L1, thereby affecting the working state of the entire compensation network. By switching the control end, the configuration of the compensation network can be changed, thereby adjusting the power transmission state of the system. The other end of the series compensation inductor L1 is connected to one end of the parallel compensation capacitor C1 and the second series compensation capacitor C p2This structure is connected by a series compensation inductor L1 and a parallel compensation capacitor C1 and a second series compensation capacitor C p2 The combination of the two together regulates the voltage and current of the system to ensure output stability. The series compensation inductor L1 plays a role in current regulation, while the parallel compensation capacitor C1 provides support for voltage stability. The second series compensation capacitor C p2 By connecting the second coil L p2 connection, further enhancing the magnetic coupling of the system and optimizing the energy transmission efficiency; the first series compensation capacitor C p1 The connection mode of is more critical. One end of it is connected to the output end of the primary inverter through the switching end of the primary controller S, and the other end is connected to the first coil L p1 , by switching the controller S, the first series compensation capacitor C p1 The connection to the inverter output can be adjusted dynamically to change the circuit's operating state. For example, in constant current mode, C p1 The connection state enables the system to adapt to load changes and maintain a stable current output; while in constant voltage mode, C p1 It helps to adjust the output voltage and ensure the realization of the voltage regulation function; in the constant current mode, the primary side controller S controls the first series compensation capacitor C p1 The switching state adjusts the stability of the current output; in the constant voltage mode, the primary controller S switches the first series compensation capacitor C p1 The connection method with the inverter adjusts the voltage output to ensure the stability of the output voltage; through the adjustment of the primary side controller S, combined with the flexible configuration of the variable compensation inductor and capacitor, the output current and voltage can be automatically adjusted according to the load demand, the power factor of the system can be improved, and the loss of invalid energy can be reduced.

[0029] Furthermore, the variable secondary compensation network includes a series compensation inductor L2, a parallel compensation capacitor C2, and a series compensation capacitor C s and secondary side switch network; One end of the series compensation inductor L2 is connected to the secondary DC power supply U through the switch tube Q6. dc2 The negative pole of the capacitor is connected to one end of the parallel compensation capacitor C2 and the series compensation capacitor C s one end of The other end of the parallel compensation capacitor C2 is connected to the node between the switch tube Q4 and the switch tube Q5; Series compensation capacitor C s The other end is connected to the secondary coil L s one end of Secondary coil L s The other end is connected to the node between the switch tube Q5 and the switch tube Q6.

[0030] As a preferred embodiment of the above, in the variable secondary compensation network, the series compensation inductor L2 is connected in series with other components in the secondary circuit, responsible for adjusting the current phase, smoothing current fluctuations, and enhancing electromagnetic coupling. One end of the series compensation inductor L2 is connected to the secondary DC power supply U through the switch tube Q6. dc2 The negative pole of the capacitor is connected to the parallel compensation capacitor C2 and the series compensation capacitor C s The parallel compensation capacitor C2 is connected to the series compensation inductor L2 to provide voltage stability and prevent excessive voltage fluctuations. The other end of the parallel compensation capacitor C2 is connected to the node between the switch tubes Q4 and Q5. The configuration of the parallel compensation capacitor C2 can effectively improve the voltage stability of the secondary side and ensure that the voltage of the secondary side will not fluctuate too much during the transmission process. The series compensation capacitor C s Located in the secondary circuit, it works with the series compensation inductor L2 and the parallel compensation capacitor C2 to provide additional voltage regulation capability. One end is connected to the other end of the series compensation inductor L2, and the other end is connected to the secondary coil L s One end of the series compensation capacitor C s The secondary current is further stabilized by connecting in series with the series compensation inductor L2 to ensure the balance of voltage and current. The secondary switch network consists of three switch tubes Q4, Q5 and Q6, which are used to switch the circuit state and control the flow of electric energy. Switch tubes Q4 and Q5 control the current flow direction of the parallel compensation capacitor C2, while switch tube Q6 is used to control the current path of the series compensation inductor L2. The other end of the parallel compensation capacitor C2 is connected to the node between the switch tubes Q4 and Q5, providing a control point for the flow of electric energy. The secondary coil L s The other end of the series compensation inductor L2 is connected to the node between the switch tubes Q5 and Q6, forming a closed path for current flow to ensure the transmission and feedback of electric energy; one end of the series compensation inductor L2 is connected to the switch tube Q6, and is connected to the secondary DC power supply U through the switch tube Q6. dc2 The other end is connected to the parallel compensation capacitor C2 and the series compensation capacitor C s The series configuration of these three provides the current phase adjustment function, making the secondary coil L s Can be connected with the primary coil L p1 The other end of the parallel compensation capacitor C2 is connected to the node between the switch tubes Q4 and Q5, which determines the voltage stabilization effect of the parallel compensation capacitor C2. The control of the switch tubes Q4 and Q5 determines the charging and discharging process of the parallel compensation capacitor C2, thereby adjusting the current and voltage of the secondary side. s The other end of the secondary coil L s One end of the capacitor C s Can work together with the secondary coil to adjust magnetic coupling and power conversion efficiency; the secondary coil L sThe other end is connected to the node between the switch tubes Q5 and Q6 to form a complete current loop, ensuring the feedback or transmission of power from the secondary coil to the switch network; in the constant current mode, the secondary compensation network adjusts the parallel compensation capacitor C2 and the series compensation capacitor C s The working state of the secondary side is controlled, and the switching state of the switch tubes Q4, Q5, and Q6 is controlled to ensure the stable output of the secondary side current. The series compensation inductor L2 and the parallel compensation capacitor C2 work together to balance the secondary side current and ensure that the current output is constant to meet the load requirements. In the constant voltage mode, the secondary side compensation network adjusts the parallel compensation capacitor C2 and the series compensation capacitor C s To maintain the output voltage of the secondary side stable, the switch tubes Q4, Q5 and Q6 are switched in time according to the load demand to adjust the power output of the secondary side to keep it in a constant voltage state; through the switching control of the switch tubes Q4, Q5, Q6 and the series compensation inductor L2 and the parallel compensation capacitor C2 and the series compensation capacitor C s The collaboration between the two can achieve precise regulation of the secondary side current and voltage in different working modes, thereby ensuring the stability and efficiency of wireless power transmission.

[0031] Further, if Figure 3 , 4 As shown in , 5 and 6, the primary side controller and the secondary side controller are further configured to include: In the constant current output mode, the primary controller S is controlled to disconnect the first coil L p1 The connection node a of the secondary side is connected to the node b and the switch tubes Q4 and Q6 in the secondary side switch network are constantly turned on, so that the variable secondary side compensation network forms an LCC topology; In the constant voltage output mode, the primary side controller S is controlled to connect to the connection node a and to the first coil L. p1 , and constantly turn on the switch tube Q3 in the secondary side switch network, and constantly turn off the switch tube Q6, so that the variable secondary side compensation network forms an S-type topology.

[0032] As a preferred embodiment of the above, in the constant current mode, the primary controller S controls its switching end to disconnect the first coil L p1 The connection node a is connected to the node b, and the coupling mechanism is a double coil. The switch tubes Q4 and Q6 are constantly turned on, and the switch tubes Q1 and Q2 are alternately turned on with a duty cycle of 50%. The switch tubes Q3 and Q5 do not provide a trigger signal, and only the diode works. Through switching control, the first coil L p1 The output of is switched to node b, thereby achieving a constant output of the load current; in the constant current mode, the switches Q4 and Q6 of the secondary controller are constantly turned on. The conduction of Q4 ensures that the parallel compensation capacitor C2 maintains a stable voltage, while the conduction of Q6 ensures that the series compensation inductor L2 and the series compensation capacitor C sThis configuration forms an LCC topology. Under the LCC topology, the secondary compensation network is mainly composed of a series inductor and a parallel capacitor, which can provide a stable constant current output. In the LCC topology, the series compensation inductor L2 and the parallel compensation capacitor C2 work together to ensure the stability of the secondary current. At the same time, the series compensation capacitor C s Helps regulate the output current; in constant voltage mode, the primary controller S connects the connection node a to the first coil L p1 and make sure that its connection is in the connected state, the first coil L p1 It is connected to the output end of the inverter, and the current flows through the first coil to form a constant voltage output. By adjusting the primary current, the primary controller ensures the stability of the output voltage and ensures that the voltage reaches the set value. In the constant voltage mode, the switch tube Q3 in the secondary switch network remains constantly turned on, while the switch tube Q6 is constantly turned off. The conduction of Q3 ensures the stable transmission of electric energy in the secondary circuit, and the turn-off of Q6 avoids the influence of the series compensation inductor L2 on the output current. In the S-type topology, the capacitor C s With the secondary coil L s A feedback network is formed to keep the voltage stable. This topology can provide constant voltage output while ensuring efficient energy transmission; in constant current mode, the primary controller S disconnects the first coil L p1 The secondary controller forms an LCC topology by constantly turning on the switches Q4 and Q6. This topology can ensure the stable output of the secondary current. At the same time, the configuration of the series compensation inductor L2 and the parallel compensation capacitor C2 can provide effective current compensation. In the constant voltage mode, the primary controller S connects the connection node a to the first coil L p1 , ensuring that it is connected to the inverter output, the secondary side controller forms an S-type topology by constantly turning on the switch tube Q3 and keeping the switch tube Q6 off. Under the S-type topology, the series compensation capacitor C in the secondary side compensation network s With the secondary coil L s To maintain voltage stability and ensure constant voltage, in the forward constant voltage mode, the switching arm of the primary controller S is connected to node a, the coupling mechanism is a three-coil, the switch tube Q6 is constantly off, the switch tube Q3 is constantly on, the switch tubes Q1 and Q2 are alternately turned on with a duty cycle of 50%, the switch tubes Q4 and Q5 do not provide a trigger signal, and only the diode works. In the reverse constant voltage mode, the switch tubes Q4 and Q5 are alternately turned on with a duty cycle of 50%, the switch tubes Q1 and Q2 do not provide a trigger signal, and only the diode works.

[0033] Specifically, when bidirectional transmission mode is executed, it includes: In forward transmission, the primary inverter operates in a high-frequency inverter state, and the secondary switching network operates as a half-wave rectifier; During reverse transmission, the secondary side switch network switches to half-bridge inverter state, and the primary side inverter operates as a half-wave rectifier.

[0034] As a preferred embodiment of the above, in the forward transmission mode, electric energy is transmitted from the primary side to the secondary side. In this mode, the primary side inverter operates in a high-frequency inversion state, and the secondary side switch network operates as a half-wave rectifier, so that electric energy can be effectively transmitted from the primary side to the secondary side through electromagnetic coupling; in the forward transmission process, the main function of the primary side inverter is to convert the input DC power into high-frequency AC power so as to pass through the first coil L p1 and the second coil L p2Electromagnetic coupling transmission is carried out. The primary inverter converts the electric energy into AC power at high frequency by adjusting the switching frequency and working mode of the switch tube to ensure efficient transmission of electric energy to the secondary side. The secondary switch network works as a half-wave rectifier at this time, which means that the working mode of the secondary switch tube only allows current to flow in one direction, and is usually only turned on in one and a half cycles. The switch tubes Q4 and Q6 in the secondary switch network work together to convert the received high-frequency AC signal into DC power through half-wave rectification and supply it to the secondary load. In the forward transmission mode, the primary inverter converts DC power into high-frequency AC power. The secondary switch network receives these AC signals as a rectifier and converts them into DC power, which is transmitted to the secondary load. This configuration effectively reduces the fluctuation of current and voltage, and improves the stability and efficiency of power transmission. In the reverse transmission mode, the direction of power transmission is opposite, that is, it is transmitted from the secondary side to the primary side. In this mode, the working state of the secondary side switch network is switched to the half-bridge inverter state, and the primary side inverter operates as a half-wave rectifier. The secondary side switch network is switched to the half-bridge inverter working state, that is, the secondary side switches Q3, Q4, Q5 and Q6 will be turned on and off at appropriate times to achieve DC current inversion. When in the reverse constant current mode, the switch tubes Q3 and Q5 are alternately turned on with a duty cycle of 50%. The switch tubes Q1 and Q2 do not provide trigger signals, and only the diodes work. The secondary side will be switched from The DC power received by the load is converted into high-frequency AC power. The secondary inverter structure can ensure that the current can be efficiently transmitted between the secondary and primary sides, and the system can control the output direction of voltage and current. In the reverse transmission mode, the primary inverter switches to the half-wave rectifier mode, which is responsible for converting the AC signal transmitted from the secondary side into DC power for the primary load or feedback to the power grid. In the half-wave rectifier mode, the primary inverter can receive and rectify the AC signal from the secondary inverter and convert it into a stable DC current. In the reverse transmission mode, the secondary side transmits energy in reverse to the primary side through the half-bridge inverter. The primary inverter receives these AC powers as a half-wave rectifier and converts them into stable DC power. Feedback to the grid or load, this reverse transmission mode contributes to the bidirectional power flow of the system and improves the energy recovery efficiency of the system; in the forward transmission mode, the primary inverter adjusts the high-frequency inverter frequency and working mode according to the load demand to ensure that the AC power passing through the primary coil can be stably transmitted to the secondary side, and the secondary switch network processes these AC signals through half-wave rectification and converts them into stable DC power output to the secondary load; in the reverse transmission mode, the secondary switch network switches to a half-bridge inverter to generate high-frequency AC power by controlling the on and off of the switch tube. The primary inverter works as a half-wave rectifier, rectifying the AC signal from the secondary side and converting it into DC power, which is fed back to the primary side or the grid.

[0035] Furthermore, the parameters of the variable primary compensation network and the variable secondary compensation network should satisfy the following resonance conditions: ; ; ; ; ; Where, ω is the operating angular frequency of the system, L1 is the series compensation inductor, C1 is the parallel compensation capacitor, L2 is the series compensation inductor, C2 is the parallel compensation capacitor, L s is the secondary coil, C s is the series compensation capacitor, L p1 For the first coil, C p1 is the first series compensation capacitor, L p2 For the second coil, C p2 is the second series compensation capacitor.

[0036] As a preferred embodiment of the above, by adjusting the inductance value of the primary and secondary coils and the corresponding compensation capacitors, the resonant frequencies of the two are ensured to be consistent. This can usually be achieved by increasing or decreasing the number of turns of the coil, changing the material of the inductor, adjusting the capacitance value, etc.; to ensure zero phase difference resonance, the resonant frequencies of the primary and secondary sides must be consistent. Specifically, the values ​​of the inductor and the capacitor are adjusted so that the resonant frequencies of the two are equal; the operating frequency of the inverter is adjusted by the controller to ensure that during operation, the voltage and current of the primary and secondary sides always maintain zero phase difference. This control strategy can be achieved by dynamically adjusting the compensation network of the circuit. For example, the primary controller can monitor the changes in the magnetic field between the primary coil and the secondary coil in real time, and Adjust the inverter frequency and the working state of the compensation capacitor according to the feedback information; use appropriate compensation inductor and capacitor components (such as LCC, S-type topology, etc.) to ensure the phase synchronization of the magnetic field. The function of the compensation network is to adjust the phase of the current and compensate for the phase difference caused by coupling asymmetry, thereby achieving zero phase difference resonance; by reasonably selecting the value of the compensation element, adjust the magnetic coupling between the primary and secondary sides to maintain the phase synchronization of the current; in the high-frequency inverter working mode, the high-frequency signal output by the primary inverter needs to be synchronized with the signal received by the secondary side to ensure that the phase difference between the two is zero. By using a precise frequency adjustment mechanism, the primary inverter can adjust the output frequency according to the feedback information of the secondary signal, thereby maintaining the phase synchronization of the two.

[0037] Further, if Figure 7 As shown, the system provides a constant current independent of the load in the constant current output mode and a constant voltage independent of the load in the constant voltage output mode through the coordinated switching of the asymmetric coupling structure and the variable compensation network.

[0038] Embodiment 2: Based on the same inventive concept as the asymmetric coupling variable coil type bidirectional wireless power transmission system in the aforementioned embodiment, the present invention further provides an asymmetric coupling variable coil type bidirectional wireless power transmission method, the method comprising: Collect the two-end power parameters of the output and input ends in real time, and analyze and obtain the regulation requirements; According to the regulation requirements, physical switching of the primary side controller contacts and logical reconstruction of the secondary side switch tube network are controlled to generate a multi-dimensional control framework; Based on the two-terminal electric energy parameters of the variable primary compensation network and the variable secondary compensation network, a bidirectional zero phase difference resonance condition is established; According to the multi-dimensional control framework and the spatial orthogonal layout of the first coil and the second coil, a mutual inductance adjustment channel of the primary and secondary coils is constructed to maintain a bidirectional transmission path while eliminating redundant coupling; Based on the synergistic effect of the multi-dimensional control framework and the bidirectional zero phase difference resonance condition, load-independent constant current or constant voltage output is achieved in a bidirectional transmission scenario through the current source characteristics of the LCC topology and the voltage source characteristics of the SS topology.

[0039] The above adjustment method in the present invention can effectively realize an asymmetric coupled variable coil type bidirectional wireless power transmission system, and the technical effects that can be achieved are as described in the above embodiments, which will not be repeated here.

[0040] Embodiment three; Based on the same inventive concept as an asymmetric coupling variable coil type bidirectional wireless power transmission system in the aforementioned embodiment, the present invention also provides an asymmetric coupling variable coil type bidirectional wireless power transmission device for realizing an asymmetric coupling variable coil type bidirectional wireless power transmission system.

[0041] The above-mentioned device in the present invention can effectively realize an asymmetric coupled variable coil type bidirectional wireless power transmission system, and the technical effects that can be achieved are as described in the above-mentioned embodiments, which will not be repeated here.

[0042] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present application as defined therein, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, a person skilled in the art may make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalents, the present application is intended to include these modifications and variations.

Claims

1. An asymmetric coupled variable coil bidirectional wireless power transmission system, characterized in that: The system comprises a grid-side unit and a load-side unit, wherein: The grid side unit includes a primary DC power supply U dc1 ; A primary inverter, including switch tubes Q1 and Q2, connected to the primary DC power supply; a variable primary compensation network, connected to the primary inverter; a primary coil assembly, consisting of a first coil L p1 and the second coil L p2 A primary side controller is configured to switch the connection state of the variable primary side compensation network; The load side unit includes a secondary DC power supply U dc2 ; A secondary switch network, including switch tubes Q3, Q4, Q5, Q6, connected to the secondary DC power supply; a variable secondary compensation network, connected to the secondary switch network; a secondary coil L s ; A secondary side controller, adjusting the conduction state of the secondary side switch network; According to the primary coil assembly and the secondary coil L s The asymmetric coupling structure is used to perform wireless bidirectional constant current or wireless bidirectional constant voltage transmission of electric energy.

2. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 1, characterized in that: In the primary coil assembly, the first coil L p1 is a toroidal coil, the second coil L p2 It is a double D-type coil; The first coil is arranged around the second coil, and a ferrite isolation layer is arranged between the two; The secondary coil L s is a ring coil, wound on the ferrite substrate, and connected with the first coil L p1 Arranged vertically in space.

3. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 1, characterized in that: The variable primary compensation network includes a series compensation inductor L1, a parallel compensation capacitor C1, a first series compensation capacitor C p1 , the second series compensation capacitor C p2 And the primary side controller S; The switching end of the primary controller S is connected between the output end of the primary inverter and the series compensation inductor L1; The other end of the series compensation inductor L1 is connected to one end of the parallel compensation capacitor C1 and the second series compensation capacitor C p2 one end of The second series compensation capacitor C p2 The other end is connected to the second coil L p2 ; The first series compensation capacitor C p1 One end of the primary side controller S is connected to the primary side inverter output end, and the other end is connected to the first coil L p1 .

4. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 1, characterized in that: The variable secondary compensation network includes a series compensation inductor L2, a parallel compensation capacitor C2, and a series compensation capacitor C s and the secondary side switch network; One end of the series compensation inductor L2 is connected to the secondary DC power supply U through the switch tube Q6. dc2 The negative electrode of the capacitor C2 is connected to one end of the parallel compensation capacitor C2 and the series compensation capacitor C s one end of The other end of the parallel compensation capacitor C2 is connected to the node between the switch tube Q4 and the switch tube Q5; The series compensation capacitor C s The other end is connected to the secondary coil L s one end of The secondary coil L s The other end is connected to the node between the switch tube Q5 and the switch tube Q6.

5. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 1, characterized in that: The primary side controller and the secondary side controller are further configured to include: In the constant current output mode, the primary side controller S is controlled to disconnect the first coil L p1 A connection node a is connected to a node b and the switch tubes Q4 and Q6 in the secondary switch network are constantly turned on, so that the variable secondary compensation network forms an LCC topology; In the constant voltage output mode, the primary side controller S is controlled to connect to the connection node a and to the first coil L. p1 , and the switch tube Q3 in the secondary side switch network is constantly turned on, and the switch tube Q6 is constantly turned off, so that the variable secondary side compensation network forms an S-type topology.

6. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 1, characterized in that: When bidirectional transmission mode is executed, it includes: During forward transmission, the primary inverter operates in a high-frequency inversion state, and the secondary switch network operates as a half-wave rectifier; During reverse transmission, the secondary side switch network is switched to a half-bridge inverter state, and the primary side inverter operates as a half-wave rectifier.

7. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 6, characterized in that: The parameters of the variable primary compensation network and the variable secondary compensation network should satisfy the following resonance conditions: ； ； ； ； ； Where, ω is the operating angular frequency of the system, L1 is the series compensation inductor, C1 is the parallel compensation capacitor, L2 is the series compensation inductor, C2 is the parallel compensation capacitor, L s is the secondary coil, C s is the series compensation capacitor, L p1 For the first coil, C p1 is the first series compensation capacitor, L p2 For the second coil, C p2 is the second series compensation capacitor.

8. The asymmetric coupled variable coil bidirectional wireless power transmission system according to claim 1, characterized in that: The system provides a constant current independent of the load in a constant current output mode and provides a constant voltage independent of the load in a constant voltage output mode through the coordinated switching of the asymmetric coupling structure and the variable compensation network.

9. An asymmetric coupled variable coil type bidirectional wireless power transmission method, characterized in that: The method comprises: Collect the two-end power parameters of the output and input ends in real time, and analyze and obtain the regulation requirements; According to the regulation requirements, physical switching of the primary side controller contacts and logical reconstruction of the secondary side switch tube network are controlled to generate a multi-dimensional control framework; Based on the two-terminal electric energy parameters of the variable primary compensation network and the variable secondary compensation network, a bidirectional zero phase difference resonance condition is established; According to the multi-dimensional control framework and the spatial orthogonal layout of the first coil and the second coil, a mutual inductance adjustment channel of the primary and secondary coils is constructed to maintain a bidirectional transmission path while eliminating redundant coupling; Based on the synergistic effect of the multi-dimensional control framework and the bidirectional zero phase difference resonance condition, load-independent constant current or constant voltage output is achieved in a bidirectional transmission scenario through the current source characteristics of the LCC topology and the voltage source characteristics of the SS topology.

10. An asymmetric coupled variable coil type bidirectional wireless power transmission device, used to implement the asymmetric coupled variable coil type bidirectional wireless power transmission system as claimed in claims 1-8.

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