A clc-clcc inductive wireless power transfer system and design method

Abstract

The application discloses a CLC-CLCC induction wireless power transmission system and a design method, and the system is sequentially connected by a direct-current power supply, an inverter circuit, a primary CLC compensation network, a magnetic coupling mechanism, a secondary CLC compensation network and a rectification filter circuit. The direct-current power supply is used for power supply, and the inverter circuit is used for generating high-frequency alternating current. The resonant parameters of the primary CLC compensation network and the secondary CLC compensation network are jointly configured, the amplitude ratio and the phase difference between the primary transmitting coil current and the secondary receiving coil current of the magnetic coupling mechanism are controlled, the resultant magnetic induction intensity of the space alternating magnetic field is reduced under the premise of the same transmission power level, and thus the eddy current loss generated by the system in the transmission medium such as seawater is effectively inhibited. In addition, the system can provide load-independent constant voltage output and realize zero phase angle on the input side, and the transmission efficiency, load adaptability and operation stability of the wireless power transmission system are comprehensively improved.

Description

Technical Field

[0001] This invention belongs to the field of inductive wireless power transfer technology, specifically relating to a CLC-CLCC inductive wireless power transfer system and its design method. Background Technology

[0002] Underwater wireless power transfer technology enables contactless power replenishment for underwater equipment such as autonomous underwater vehicles and seabed observation networks. Compared to traditional underwater wet-plug charging technology, wireless power transfer technology completely eliminates the safety hazards associated with physical connectors, such as leakage, seawater corrosion, and wear, offering significant advantages such as safety, reliability, and strong environmental adaptability. Currently, magnetic coupling inductive wireless power transfer (IPT) is the mainstream technology for achieving medium-to-high power transfer underwater.

[0003] Unlike air, seawater is a typical high-conductivity loss medium. When an IPT system operates in seawater, the high-frequency alternating magnetic field generated by the primary-secondary coupling mechanism induces significant eddy currents in the surrounding seawater. This eddy current effect not only greatly increases the system's transmission loss (i.e., seawater eddy current loss), leading to a sharp decrease in transmission efficiency, but also causes abnormal heating of the surrounding water. Therefore, effectively suppressing the eddy current loss induced by the high-frequency magnetic field in seawater is a key technical challenge that urgently needs to be solved in the field of underwater wireless power transmission.

[0004] Compensation topology circuits are core components of inductive wireless power transfer systems. Currently, existing compensation circuits are mainly divided into basic topologies and high-order topologies. For example, Chinese invention patent CN111835092B provides a bilateral LCC (inductor-capacitor-capacitor) compensation network adjustment method and system for a wireless charging system. This system achieves efficient power transfer through a bilateral LCC network. However, traditional high-order LCC-LCC topologies primarily pursue zero-phase-angle (ZPA) and constant output characteristics in parameter design, and cannot control the specific phase difference between the primary and secondary coil currents through passive network parameter adjustment. Therefore, in high-conductivity seawater environments, high-frequency leakage magnetic fields still induce severe eddy current losses. Furthermore, when facing wide load conditions with varying resistance values ​​of underwater equipment, such topologies struggle to maintain low conduction losses in the inverter.

[0005] Chinese patent application CN111313564A discloses a wireless power transmission system for an underwater unmanned submersible. This technology also addresses the problem of eddy current loss caused by high-frequency alternating magnetic fields in highly conductive underwater media. It constructs a matrix-style transmitting coil charging channel and implements localized control of corresponding areas. Its main function is to reduce seawater eddy current loss at the physical level by decreasing the actual power transmission area and limiting the spatial exposure range of the magnetic field. However, the drawback of this solution is that it relies entirely on the physical switching of the external coil array and fails to provide a means of actively controlling or counteracting the spatial alternating magnetic field from the excitation source of the circuit topology's intrinsic parameters.

[0006] Chinese invention patent CN109546758B discloses an underwater wireless power transmission system utilizing distributed capacitance for signal transmission. This system, addressing the hazards of seawater eddy current losses, employs a composite architecture for synchronous energy and signal transmission. Real-time data exchange between the primary and secondary sides is achieved through distributed capacitance channels between the plates, coupled with a corresponding closed-loop control algorithm to dynamically adjust the converter's operating state, aiming to maintain high energy transmission efficiency and system control precision in complex and variable underwater environments. However, this approach, relying on complex signal modulation and demodulation circuits and additional active control modules, increases system hardware complexity and manufacturing costs. Furthermore, it is susceptible to high-frequency electromagnetic interference in seawater environments, making it difficult to achieve the high reliability of static wide-load adaptability with a minimalist structure, unlike a purely passive compensation topology.

[0007] In summary, for the practical applications of wireless power transfer in today's marine environments, current conventional compensation circuit topologies and parameter design methods struggle to simultaneously meet the stringent requirements of actively suppressing seawater eddy current losses and maintaining low inverter conduction losses in a purely passive state. How to comprehensively address the aforementioned pain points of inductive wireless power transfer systems without increasing system control complexity and physical size is a crucial technical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0008] To address the technical problem that in existing wireless power transmission systems operating in transmission media such as seawater, high-frequency alternating magnetic fields easily induce strong alternating electromotive forces and generate severe eddy current losses, leading to a significant decrease in the overall transmission efficiency of the system, this invention provides a CLC-CLCC inductive wireless power transmission system and its design method. The aim is to reduce the spatial magnetic flux density at the same transmission power level by relying on the parameter configuration of a purely passive compensation network, without adding complex active control modules and physical shielding structures, based on the intrinsic properties of the circuit topology. This achieves active and effective suppression of eddy current losses induced by spatial magnetic fields in wireless power transmission systems operating in transmission media such as seawater.

[0009] A CLC-CLCC inductive wireless power transfer system comprises, in sequence, a DC power supply, an inverter circuit, a primary-side CLC (capacitor-inductor-capacitor) compensation network, a magnetic coupling mechanism, a secondary-side CLCC (capacitor-inductor-capacitor-capacitor) compensation network, a rectifier and filter circuit, and a load connection, wherein: The DC power supply is used to provide DC input voltage; The inverter circuit is used to convert DC input voltage into high-frequency AC voltage. The primary-side CLC compensation network is used to perform resonance compensation and impedance transformation on the high-frequency AC voltage, so that the system input terminal matches the zero-phase input state and outputs a high-frequency AC current to the primary-side transmitting coil of the magnetic coupling mechanism. The amplitude and phase of the current are set according to the load and component parameters. The magnetic coupling mechanism includes a primary-side transmitting coil and a secondary-side receiving coil, which transmit electrical energy non-contactly through a spatial transmission medium (such as air, lake water, seawater, etc.) using a high-frequency magnetic field coupling method. The secondary-side CLCC compensation network is used to resonate and match the high-frequency AC current induced by the secondary-side receiving coil, thereby outputting a high-frequency AC voltage with constant voltage characteristics. At the same time, the secondary-side CLCC compensation network and the primary-side CLC compensation network jointly constrain each other to control the amplitude ratio and phase difference between the primary and secondary coil currents, thereby enabling the adjustment (reduction) of the combined magnetic flux density modulus between the primary and secondary coils under the premise of the same transmission power. The rectifier and filter circuit is used to rectify and filter the high-frequency AC voltage, thereby providing a stable DC output voltage to the load.

[0010] Furthermore, the primary-side CLC compensation network includes a primary-side parallel compensation inductor, a primary-side first series compensation capacitor, and a primary-side second series compensation capacitor. One end of the primary-side first series compensation capacitor is connected to the positive terminal of the AC output of the inverter circuit. The other end of the primary-side first series compensation capacitor is connected to one end of the primary-side parallel compensation inductor and one end of the second series compensation capacitor. The other end of the second series compensation capacitor is connected to the same-name terminal of the primary-side transmitting coil. The other end of the primary-side parallel compensation inductor is connected to the negative terminal of the AC output of the inverter circuit and the opposite-name terminal of the primary-side transmitting coil.

[0011] Furthermore, the secondary-side CLCC compensation network includes a secondary-side series compensation capacitor, a secondary-side series compensation inductor, a secondary-side first parallel compensation capacitor, and a secondary-side second parallel compensation capacitor. One end of the secondary-side series compensation capacitor is connected to the same-name terminal of the secondary-side receiving coil. The other end of the secondary-side series compensation capacitor is connected to one end of the secondary-side first parallel compensation capacitor and one end of the secondary-side series compensation inductor. The other end of the secondary-side series compensation inductor is connected to one end of the secondary-side second parallel compensation capacitor and the positive AC input terminal of the rectifier filter circuit. The other end of the secondary-side first parallel compensation capacitor is connected to the other end of the secondary-side second parallel compensation capacitor, the opposite-name terminal of the secondary-side receiving coil, and the negative AC input terminal of the rectifier filter circuit.

[0012] The inverter circuit can adopt a full-bridge inverter structure or a half-bridge inverter structure, and the rectifier and filter circuit adopts a full-bridge rectifier circuit structure. Both the primary-side transmitting coil and the secondary-side receiving coil are wound with Litz wire, and ferrite cores are provided on the outer side of the magnetic circuits of both the primary-side transmitting coil and the secondary-side receiving coil. The combined magnetic flux density between the primary-side transmitting coil and the secondary-side receiving coil is the result of the superposition of the magnetic flux density excited by the primary coil current and the magnetic flux density excited by the secondary coil current.

[0013] In the aforementioned system topology, the inductor and capacitor parameters in the primary-side CLC compensation network and the secondary-side CLCC compensation network are jointly configured according to system operating requirements. The core operating mechanism lies in controlling the amplitude ratio and specific phase difference between the primary-side transmitting coil current and the secondary-side receiving coil current by jointly setting the resonance parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network. This reduces the combined magnetic flux density of the alternating magnetic field in the spatial transmission medium, thereby actively suppressing eddy current losses generated in wireless power transmission systems in transmission media such as seawater at the same transmission power level. Therefore, this system topology can achieve zero-phase input and constant-voltage output, while also adjusting the amplitude ratio and phase difference of the primary and secondary coil currents, effectively suppressing eddy current losses at the same transmission power level.

[0014] To reduce the combined magnetic flux density in space and actively suppress eddy current losses in transmission media such as seawater while maintaining the same transmission power level, this invention implements parameter optimization. This optimization does not rely on external additional structures but rather achieves active control of the electromagnetic field by jointly adjusting the parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network, ensuring that the parameters of each inductor and capacitor in the system satisfy the parametric expression. The parameter optimization refers to controlling the amplitude ratio and phase difference between the current in the primary-side transmitting coil and the current in the secondary-side receiving coil through the joint constraints of the parameters of the aforementioned passive network components. This parameter adjustment method effectively cancels or weakens the high-frequency alternating magnetic field in the transmission space. By relying on the parameter configuration of the purely passive network, the combined magnetic induction intensity is reduced, thereby substantially reducing the combined magnetic flux density in space and suppressing eddy current losses induced by the spatial magnetic field.

[0015] The parameter design method for the aforementioned CLC-CLCC inductive wireless power transfer system includes: Based on the high-frequency operating state, the system is resonant condition matched so that the system input is matched to a zero-phase input state and the output meets the constant voltage output state. The component parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network are jointly adjusted to reduce the spatial magnetic flux density at the same transmission power level. By independently adjusting the component parameters in the primary-side CLC compensation network, the inverter's low conduction loss optimization is achieved.

[0016] Furthermore, the resonance condition matching involves selecting the component parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network based on the resonance condition to achieve efficient resonance transmission of the system. The expression for the resonance condition is as follows: , in: ω This refers to the high-frequency switching angular frequency of the inverter circuit. M This refers to the mutual inductance between the primary transmitting coil and the secondary receiving coil. L 1 represents the inductance value of the primary-side parallel compensation inductor. C p1 This is the capacitance value of the first series compensation capacitor on the primary side. C p This is the capacitance value of the second series compensation capacitor on the primary side. L p This is the self-inductance value of the primary-side transmitting coil. C s The capacitance value of the secondary-side series compensation capacitor. Csp1 This is the capacitance value of the first parallel compensation capacitor on the secondary side. L 2 represents the inductance value of the secondary-side series compensation inductor. C sp2 This is the capacitance value of the second parallel compensation capacitor on the secondary side. L s The self-inductance of the secondary receiving coil, j It is the imaginary unit.

[0017] Furthermore, the reduction of spatial magnetic flux density at the same transmission power level is achieved by controlling the amplitude ratio and phase difference between the primary side transmitting coil current and the secondary side receiving coil current by satisfying the following expression, so as to offset or weaken the high-frequency alternating magnetic field in the transmission space, thereby reducing the magnetic flux density and suppressing eddy current losses caused by the magnetic field in transmission media such as seawater. , in: The phasor of the alternating current on the primary-side transmitting coil. The AC current phasor on the secondary receiving coil, R L This is the load resistance value. R o This is the equivalent resistance of the load referred to the AC side of the rectifier and filter circuit. P This represents the output power of the inverter circuit.

[0018] Furthermore, the inverter's low conduction loss optimization involves independently adjusting the component parameters in the primary-side CLC compensation network to make the equivalent input impedance seen from the inverter circuit output terminal a highly resistive, purely resistive state. This results in the inverter output terminal exhibiting high voltage and low current characteristics. The expression for the equivalent input impedance is as follows: in: Z in To obtain the equivalent input impedance, the inductance value of the parallel compensation inductor on the primary side is adjusted. L 1 to change Z in Size.

[0019] Specifically, parameters can be configured for the rated load during the system hardware design phase, including the following steps: (1) Obtain the rated load of the system to be designed under the target application conditions, and derive its equivalent resistance value referred to the AC side of the rectifier and filter circuit. R o ; (2) The equivalent resistance value Ro As known fixed constants, they are substituted into the above expressions (i.e., the current expression and the resonance condition expression) to perform joint constraint solutions; (3) Calculate the optimal target parameter values ​​of the first parallel compensation capacitor, the second parallel compensation capacitor, and the series compensation inductor on the secondary side that are strictly matched with the rated load; (4) Based on the optimal target parameter values ​​obtained from the solution, the hardware selection and configuration of the primary CLC compensation network and the secondary CLCC compensation network are carried out; in the subsequent actual operation of the system, the component parameters of the secondary CLCC compensation network remain fixed. For any rated load requirement within a wide resistance range, the optimal target parameter values ​​can be independently obtained by performing the above steps. This allows for the joint configuration of the inductor and capacitor parameters in the primary-side CLC compensation network and the secondary-side CLCC compensation network based on system operating requirements within the system topology. This ensures that systems customized for different rated loads can meet the zero-phase-angle input and constant-voltage output characteristics under rated operating conditions, achieving low inverter conduction losses. Furthermore, by setting the resonance parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network through the above steps, the amplitude ratio and specific phase difference between the primary-side transmitting coil current and the secondary-side receiving coil current can be controlled. This reduces the combined magnetic flux density of the alternating magnetic field in the surrounding space medium, thereby lowering the combined magnetic flux density at the same transmission power level.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects: 1. At the same transmission power level, the present invention can reduce the spatial magnetic flux density, thereby suppressing eddy current losses generated by the spatial magnetic field when the wireless power transmission system operates in a transmission medium such as seawater.

[0021] 2. This invention is based on a CLC-CLCC compensation network structure. By jointly adjusting the resonance parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network, the amplitude ratio and specific phase difference between the primary-side transmitting coil current and the secondary-side receiving coil current are controlled.

[0022] 3. By controlling the amplitude ratio and specific phase difference of the current, this invention reduces the combined magnetic flux density of the alternating magnetic field jointly excited by the primary and secondary coils in the space transmission medium, thereby achieving a reduction in the combined magnetic flux density in space at the same transmission power level and effectively suppressing eddy current losses caused by the space magnetic field in transmission media such as seawater. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the topology of the CLC-CLCC inductive wireless power transfer system in an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the equivalent circuit model of the CLC-CLCC inductive wireless power transfer system in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the circuit equivalent transformation after transformer decoupling of the equivalent circuit model in an embodiment of the present invention.

[0026] Figure 4 The diagram shows the equivalent transformation of the circuit of the CLC-CLCC inductive wireless power transfer system in this embodiment of the invention after the resonance condition is met. In the diagram, (a) is the equivalent circuit of the system with equivalent resistance, (b) is the equivalent circuit of the secondary circuit converted to the primary side, and (c) is the total equivalent input impedance circuit of the system.

[0027] Figure 5 The AC side voltage of the inverter circuit in the system of this embodiment of the invention at rated power. u in and current i in and the DC output voltage of the rectifier circuit U load A waveform diagram.

[0028] Figure 6 The AC side voltage of the inverter circuit in this embodiment of the invention is at 1 / 2 rated power. u in and current i in and the DC output voltage of the rectifier circuit U load A waveform diagram.

[0029] Figure 7 The primary and secondary coil currents of the system in this embodiment of the invention are used to verify the eddy current loss suppression effect. i p and i s A waveform diagram. Detailed Implementation

[0030] To describe the present invention in more detail, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 As shown, this embodiment provides a CLC-CLCC inductive wireless power transfer system for use in seawater environments. The system is sequentially connected to a DC power supply, an inverter circuit, a primary-side CLC compensation network, a magnetic coupling mechanism, a secondary-side CLCC compensation network, a rectifier and filter circuit, and a load (whose resistance is...). R L Among them, the DC power supply (its voltage is...)U dc The DC input terminal of the inverter circuit is connected to provide DC power; the magnetic coupling mechanism includes a primary-side transmitting coil (whose self-inductance is...) L p ) and secondary receiving coil (whose self-inductance is L s The two are connected by seawater and magnetic field coupling for non-contact electrical energy transfer.

[0032] The inverter circuit adopts a full-bridge inverter architecture consisting of four power switching devices (Q1~Q4); the rectifier and filter circuit adopts a structure consisting of four rectifier diodes (D1~D4) and a filter capacitor C. L The full-bridge rectifier architecture is composed of these components.

[0033] In the primary-side CLC compensation network, the first series compensation capacitor on the primary side (its capacitance value is...) C p1 One end of the capacitor is connected to the positive terminal of the AC output of the inverter circuit, and the other end of the first series compensation capacitor on the primary side is connected to the parallel compensation inductor on the primary side (whose inductance value is...). L 1) One end and the second series compensation capacitor on the primary side (its capacitance value is C p One end of the primary-side parallel compensation inductor is connected to the negative terminal of the inverter circuit's AC output and forms a return branch; the other end of the primary-side second series compensation capacitor is connected in series with the primary-side transmitting coil.

[0034] Both the primary transmitting coil and the secondary receiving coil of the magnetic coupling mechanism are wound with Litz wire, and ferrite cores are provided on the outer side of the magnetic circuit of both the primary transmitting coil and the secondary receiving coil.

[0035] In the secondary-side CLCC compensation network, one end of the secondary-side receiving coil is connected to a secondary-side series compensation capacitor (whose capacitance value is...). C s One end of the secondary side series compensation capacitor is connected to the other end of the secondary side first parallel compensation capacitor (whose capacitance value is...). C sp1 One end of the circuit and the secondary side are connected in series with a compensating inductor (whose inductance value is...) L 2) One end of the secondary-side series compensation inductor; the other end of the secondary-side series compensation inductor is connected to the second parallel compensation capacitor (whose capacitance value is...). C sp2 One end of the secondary receiving coil and the positive terminal of the AC input of the rectifier and filter circuit are connected together; the other end of the secondary receiving coil, the other end of the first parallel compensation capacitor on the secondary side, and the other end of the second parallel compensation capacitor on the secondary side are connected together to the negative terminal of the AC input of the rectifier and filter circuit.

[0036] Figure 2For the equivalent circuit model of the CLC-CLCC inductive wireless power transfer system in this embodiment, we use the fundamental frequency analysis method to convert the inverter circuit into an equivalent circuit with an effective value of... U in High-frequency AC voltage source u in The rectifier filter circuit and the actual load resistance value R L Converted to the AC side, the equivalent resistance is R o Their fundamental equivalent relations satisfy: , This embodiment performs a circuit equivalent transformation on the equivalent circuit model after transformer decoupling, as follows: Figure 3 As shown, to clarify the impedance characteristics of the primary and secondary sides, we introduce a controlled voltage source for decoupling: a controlled voltage source is introduced in series in the primary circuit. A controlled voltage source is introduced in series in the secondary circuit. ,in ω This refers to the high-frequency switching angular frequency of the inverter circuit. M The mutual inductance of the primary and secondary coils, and Let be the AC current phasors of the primary winding and the secondary winding, respectively; after decoupling, the total equivalent input impedance of the system as seen from the inverter side is denoted as . Z in .

[0037] The derivation process of gradually simplifying the circuit impedance of the CLC-CLCC inductive wireless power transfer system in this embodiment after satisfying the preset resonance condition is as follows: Figure 4 As shown, in order to achieve the multiple technical objectives of this invention, the parameters of the passive devices in the system need to be pre-configured and satisfy the following four resonance conditions: , like Figure 4 As shown in the simplification process, after the system parameters satisfy the above formula, the secondary network including the load can be reflected to the primary side step by step. In this resonant state, the present invention actively controls the primary side current phasor through parameter configuration. Phasor of secondary current The relationship between the two strictly satisfies: As can be seen from the above equation, under this topological structure, and There exists a fixed amplitude ratio and phase difference that can be adjusted by parameters. The size of the parallel compensation capacitor on the secondary side is set jointly. C sp1 and C sp2 and the size of the secondary series compensation inductor L The specific parameters of 2 can be configured to create the required phase difference, thereby causing the alternating magnetic field generated by the primary and secondary coils to cancel each other out in the seawater medium, thus suppressing the eddy current loss of seawater from the source of electromagnetic excitation.

[0038] Figure 4 The equivalent resistance in (a) and (b) R E The equivalent impedance of the secondary winding referred to the primary winding Z p After circuit simplification and calculation, the expressions are as follows: Further integration Figure 4 The final simplified result of (c) is the total equivalent input impedance of the system. Z in It exhibits purely resistive behavior, achieving zero-phase input characteristics of the system, and the total equivalent input impedance of the system is... Z in The expression simplifies to: The above equation shows that the CLC-CLCC topology of the present invention not only achieves zero-phase input characteristics, but also has low input impedance. Z in The size of the compensation inductor connected in parallel with the primary side L 1 shows a positive correlation. This can be achieved by appropriately increasing [the value / increase] during the hardware design phase. L A sensitivity value of 1 makes Z in It exhibits a high-impedance state; this configuration allows the inverter circuit to maintain a high-level AC voltage while significantly compressing the AC current amplitude (i.e., exhibiting a high-voltage, low-current state) when outputting the same apparent power. This characteristic greatly reduces the conduction losses of the power switching devices in the inverter and provides favorable conditions for achieving zero-voltage turn-on.

[0039] Based on the above theoretical derivation, this embodiment provides a method for optimizing the resonance parameters of a corresponding load: for different application scenarios within a wide resistance range, the rated load resistance value for that scenario is obtained. R L And converted to R o ;Will R oSubstituting these known constants into the constraints of the aforementioned characteristic formula; by solving this system of equations, the load that is strictly matched to this specific rated load can be calculated. C sp1 , C sp2 and L The optimal target parameters for 2 are determined, and the hardware configuration of the system is finalized based on these parameters. This method ensures that the system can achieve a comprehensive optimization of constant voltage output, low conduction loss, and low eddy current loss in seawater conduction medium by relying on the configuration of purely passive components when facing different rated load requirements.

[0040] To better verify the technical effects of the present invention, we designed and built an experimental prototype platform for use in a seawater environment. The prototype was tested by filling an acrylic water tank with seawater, which has a length, width and height of 560mm×560mm×350mm. The high-frequency switching frequency was set to 85kHz, the target transmission distance was 35cm, the input rated power was 500W, the input DC voltage was 210V, and the output voltage was constant at 57V.

[0041] The prototype was designed based on the parameter design method provided by this invention, and the specific parameters are shown in Table 1: Table 1 like Figure 5 and Figure 6 As shown, DC output voltage U load The output voltage ranged from 57V to 58V at different power levels, which was basically the set constant voltage output value. This experimental result proves that the output characteristics of the present invention are consistent with the design.

[0042] Depend on Figure 5 and Figure 6 As can be seen, the system achieves zero-phase input characteristics at different power levels. Since the inverter needs to achieve zero-voltage turn-on to reduce turn-on losses, AC current measurement... i in The phase lags slightly behind the AC voltage measurement. u in The phase.

[0043] Figure 7 This demonstrates the primary-side emitter coil current during steady-state operation of the system. i p With the secondary receiving coil current i sThe measured waveform objectively shows a significant phase difference between the currents in the two coils, which matches the theoretical value set by the derived formula. This phenomenon indicates that the system has successfully achieved phase control of the primary and secondary currents, providing direct physical support for suppressing eddy current losses generated during wireless power transmission in the seawater medium.

[0044] Depend on Figure 7 It can be seen that the drain-source voltage of the MOSFET on the inverter side u ds With corresponding gate drive signal u gs There is a dead time between the waveforms, which is related to the drain-source voltage of the field-effect transistor. u ds When the gate drive signal drops to 0, u gs Only when the voltage level is high will the field-effect transistor turn on, achieving zero-voltage turn-on.

[0045] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. Those skilled in the art can readily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made to the present invention by those skilled in the art based on the disclosure thereof should be within the scope of protection of the present invention.

Claims

1. A CLC-CLCC inductive wireless power transfer system, characterized in that, include: A DC power supply, used to provide DC input voltage; An inverter circuit is used to convert a DC input voltage into a high-frequency AC voltage. The primary-side CLC compensation network is used to perform resonance compensation and impedance transformation on the high-frequency AC voltage, so that the system input terminal matches the zero-phase angle input state and outputs high-frequency AC current to the primary-side transmitting coil of the magnetic coupling mechanism. The magnetic coupling mechanism includes a primary-side transmitting coil and a secondary-side receiving coil, which transmit electrical energy non-contactly through a spatial transmission medium using a high-frequency magnetic field coupling method. The secondary-side CLCC compensation network is used to resonate and match the high-frequency AC current induced by the secondary-side receiving coil, thereby outputting a high-frequency AC voltage with constant voltage characteristics; at the same time, the secondary-side CLCC compensation network and the primary-side CLC compensation network jointly constrain each other to control the amplitude ratio and phase difference between the primary and secondary coil currents. The rectifier and filter circuit is used to rectify and filter high-frequency AC voltage with constant voltage characteristics, thereby providing a stable DC output voltage to the load. The primary-side CLC compensation network includes a primary-side parallel compensation inductor, a primary-side first series compensation capacitor, and a primary-side second series compensation capacitor. The secondary-side CLCC compensation network includes a secondary-side series compensation capacitor, a secondary-side series compensation inductor, a secondary-side first parallel compensation capacitor, and a secondary-side second parallel compensation capacitor, and satisfies the following resonance condition: ， in: ω This refers to the high-frequency switching angular frequency of the inverter circuit. M This refers to the mutual inductance between the primary transmitting coil and the secondary receiving coil. L 1 represents the inductance value of the primary-side parallel compensation inductor. C p1 This is the capacitance value of the first series compensation capacitor on the primary side. C p This is the capacitance value of the second series compensation capacitor on the primary side. L p This is the self-inductance value of the primary-side transmitting coil. C s The capacitance value of the secondary-side series compensation capacitor. C sp1 This is the capacitance value of the first parallel compensation capacitor on the secondary side. L 2 represents the inductance value of the secondary-side series compensation inductor. C sp2 This is the capacitance value of the second parallel compensation capacitor on the secondary side. L s This is the self-inductance value of the secondary receiving coil. j It is the imaginary unit.

2. The CLC-CLCC inductive wireless power transfer system according to claim 1, characterized in that: One end of the first series compensation capacitor on the primary side is connected to the positive terminal of the AC output of the inverter circuit. The other end of the first series compensation capacitor on the primary side is connected to one end of the parallel compensation inductor on the primary side and one end of the second series compensation capacitor. The other end of the second series compensation capacitor is connected to the same-name terminal of the primary-side transmitting coil. The other end of the parallel compensation inductor on the primary side is connected to the negative terminal of the AC output of the inverter circuit and the opposite-name terminal of the primary-side transmitting coil.

3. The CLC-CLCC inductive wireless power transfer system according to claim 1, characterized in that: One end of the secondary-side series compensation capacitor is connected to the same-name terminal of the secondary-side receiving coil. The other end of the secondary-side series compensation capacitor is connected to one end of the secondary-side first parallel compensation capacitor and one end of the secondary-side series compensation inductor. The other end of the secondary-side series compensation inductor is connected to one end of the secondary-side second parallel compensation capacitor and the positive AC input terminal of the rectifier filter circuit. The other end of the secondary-side first parallel compensation capacitor is connected to the other end of the secondary-side second parallel compensation capacitor, the opposite-name terminal of the secondary-side receiving coil, and the negative AC input terminal of the rectifier filter circuit.

4. The CLC-CLCC inductive wireless power transfer system according to claim 1, characterized in that: The inverter circuit adopts a full-bridge inverter structure or a half-bridge inverter structure, and the rectifier and filter circuit adopts a full-bridge rectifier circuit structure; both the primary-side transmitting coil and the secondary-side receiving coil are wound with Litz wire, and ferrite cores are provided on the outer side of the magnetic circuit of both the primary-side transmitting coil and the secondary-side receiving coil.

5. The parameter design method for the CLC-CLCC inductive wireless power transfer system as described in any one of claims 1 to 4, characterized in that: Based on the high-frequency operating state, the system is resonant condition matched so that the system input is matched to a zero-phase input state and the output meets the constant voltage output state. The component parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network are jointly adjusted to reduce the spatial magnetic flux density at the same transmission power level. By independently adjusting the component parameters in the primary-side CLC compensation network, the inverter's low conduction loss optimization is achieved.

6. The parameter design method according to claim 5, characterized in that, The resonant condition matching refers to selecting the component parameters of the primary-side CLC compensation network and the secondary-side CLCC compensation network through resonant conditions to achieve efficient resonant transmission of the system.

7. The parameter design method according to claim 6, characterized in that, The reduction of spatial magnetic flux density at the same transmission power level is achieved by controlling the amplitude ratio and phase difference between the primary transmitting coil current and the secondary receiving coil current by satisfying the following expression, so as to cancel or weaken the high-frequency alternating magnetic field in the transmission space. ， in: The phasor of the alternating current on the primary-side transmitting coil. The AC current phasor on the secondary receiving coil, R L This is the load resistance value. R o This is the equivalent resistance of the load referred to the AC side of the rectifier and filter circuit. P This represents the output power of the inverter circuit.

8. The parameter design method according to claim 7, characterized in that, The inverter low conduction loss optimization is achieved by independently adjusting the component parameters in the primary-side CLC compensation network, so that the equivalent input impedance of the system seen from the inverter circuit output is a high-resistivity pure resistive state. The expression for the equivalent input impedance is as follows: in: Z in To obtain the equivalent input impedance, the inductance value of the parallel compensation inductor on the primary side is adjusted. L 1 to change Z in Size.

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