High-frequency wireless battery charging system based on trajectory optimization and matching network integration and design method

Abstract

The invention discloses a high-frequency wireless battery charging system based on trajectory optimization and matching network integration and a design method, and relates to the field of high-frequency wireless power transmission. The problems that in the prior art, monitoring of a battery charging curve can be achieved only by combining with large adjustment of input voltage, but components are various, control, detection and regulation schemes are generally complex, and the original intention of high-frequency miniaturization design is deviated to a certain extent are solved. According to the system, a T-type IMN network is constructed, the T-type IMN network comprises an XT1 impedance and an XT2 impedance, the XT1 impedance comprises an LC1 and an LV1, the XT1 impedance in the T-type IMN network is integrated with an output filtering resonant inductor L0 of a power amplifier PA, the XT2 impedance comprises an LC2 and a CV2, the XT2 impedance is integrated with a coil series capacitor Ctx, and residual capacitors in the T-type IMN network are used for device multiplexing. The method is also suitable for the field of change design of dual-mode impedance tracks.

Description

Technical Field

[0001] The present invention relates to the technical field of high-frequency wireless power transmission, and in particular to a high-frequency wireless battery charging system and a design method based on trajectory optimization and matching network integration. Background Art

[0002] With the rapid development of the third-generation semiconductor technology, wireless power transfer (WPT) technology has profoundly affected all aspects of people's production and life.

[0003] The most common charging device is the battery load. To extend its cycle life, the WPT system generally uses constant current (CC) and constant voltage (CV) dual modes for charging. For traditional kilohertz low-frequency WPT systems, the commonly used CC / CV methods include: phase shift control, frequency modulation, cascaded DC / DC circuits, active rectifiers, phase-locked loop pulse width modulation, multi-stage constant current charging, and topology reconfigurable design.

[0004] For the basic phase shift control method, CC / CV is generally achieved by changing the phase shift angle. The principle is simple, but the soft switching range generally cannot cover the entire working range. For frequency modulation, the inverter power transmission frequency is usually changed. The resonant topology can obtain different output characteristics at different frequencies. Therefore, CC / CV output can be achieved without adding circuits.

[0005] However, this is usually at the expense of a significant increase in the reactive component of the system in the CC phase or the CV phase, which means a reduction in efficiency. For cascaded DC / DC circuits, this approach is more engineering-oriented and has higher reliability. Therefore, the number of components is usually higher. Using an active rectifier is also a good choice, which can optimize the transmission efficiency and save the DC / DC converter. For phase-locked loop pulse width modulation, this method can achieve soft switching and constant output. But the zero voltage (Zero Voltage Switching, ZVS) angle is usually fixed and cannot be flexibly adjusted. For multi-stage constant current charging, it has the advantages of short charging time, high flexibility and low temperature rise. However, the cut-off voltage of this method may be slightly higher than that of the traditional CC / CV method. Whether it will have an adverse effect on battery life is still relatively unclear. Topology reconstruction is also a feasible design idea, such as LCC / S to SS, three-coil structure, etc. But how to improve its power density is one of the key factors to meet the requirements of future lightweight drive power supplies.

[0006] High frequency is beneficial to reduce system size, especially for industrial, scientific and medical frequency band systems, namely 6.78MHz, 13.56MHz and 27.12MHz. However, the above traditional CC / CV method cannot be directly applied to MHz Class-E converter systems with higher efficiency and sensitivity. This is due to the high-frequency non-resistive conduction problem. Static impedance compression is often used in high-frequency systems, which can optimize the load conditions of the power amplifier (PA) and the coupling coil and provide new degrees of freedom in parameter design.

[0007] However, this technology often requires a significant adjustment of the input voltage to achieve the battery charging curve. Dynamic impedance matching is also a feasible solution, but it has many components and the control, detection and regulation schemes are generally complex, which to some extent deviates from the original design intention of high-frequency miniaturization. Summary of the invention

[0008] The present invention aims to solve the problem that the existing technology often requires a large adjustment of the input voltage to realize the monitoring of the battery charging curve. Dynamic impedance matching is also one of the feasible solutions, but it has many components and the control detection and regulation scheme is generally complicated, which deviates from the original design intention of high-frequency miniaturization to a certain extent.

[0009] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0010] Solution 1: The present invention proposes a high-frequency wireless battery charging system based on trajectory optimization and matching network integration. The high-frequency wireless battery charging system constructs a T-type IMN network based on a constant current mode CCM and a constant voltage mode CVM. The T-type IMN network includes X T1 Impedance and X T2 Impedance, the X T1 Impedance includes L C1 and L V1 , X in the T-type IMN network T1 The impedance is integrated with the output filter resonant inductor L0 of the power amplifier PA and simplified to a single inductor L 1； The X T2 Impedance includes L C2 and C V2 , the X T2 Impedance and coil series capacitance C tx Integrated, simplified to a single capacitor and The remaining capacitance in the T-type IMN network is used for device reuse.

[0011] Further, a preferred embodiment is provided, wherein X in the constant current mode CCM and the constant voltage mode CVM mode T1 The impedance values ​​are equal.

[0012] Furthermore, a preferred embodiment is provided, wherein the high frequency wireless battery charging system further comprises a step of switching between a constant current mode CCM and a constant voltage mode CVM.

[0013] Furthermore, a preferred implementation manner is provided, wherein the conversion between the constant current mode CCM and the constant voltage mode CVM is achieved by a double-pole relay.

[0014] Further, a preferred embodiment is provided, wherein the output filter resonant inductor L0 of the power amplifier PA is integrated before the output impedance Z is determined. pa , reflected impedance Z ref , coil input impedance Z coil steps.

[0015] Furthermore, a preferred implementation manner is provided, wherein the power amplifier PA maintains a soft switching state during the entire charging process.

[0016] Furthermore, a preferred implementation is provided, wherein the high-frequency wireless battery charging system based on trajectory optimization and matching network integration is obtained by performing load traction simulation using ADS software.

[0017] Solution 2: A design method for a high-frequency wireless battery charging system based on trajectory optimization and matching network integration, the design method for a high-frequency wireless battery charging system comprising the following steps:

[0018] S1. Determine the load R according to the output requirements of constant current mode CCM and constant voltage mode CVM. Lmin To R Lmax The variation range and maximum power load point R S ;

[0019] S2. Establish the relationship between the rectifier input impedance and the coil efficiency; solve the load R Lmin To R Lmax The limit value of the variation range determines the real component impedance R of the rectifier input impedance rec_opt and peak coil efficiency;

[0020] S3, according to the real component impedance R rec_opt Determine the type of rectifier and parallel capacitor C used r The value of the maximum power load point R S The corresponding rectifier input real impedance R rec Equal to R rec_opt ;

[0021] S4, design a dual-mode IMN network;

[0022] S5. Based on the parameters in the dual-mode IMN network used for integration and device reuse, the design of a high-frequency wireless battery charging system integrating trajectory optimization and matching network is completed.

[0023] The present invention is beneficial in that:

[0024] The high-frequency wireless battery charging system and design method based on trajectory optimization and matching network integration described in the present invention aims to achieve efficient and stable battery charging curve, full-range soft switching, and extreme compression of input voltage changes without wasting the miniaturization advantages of the high-frequency WPT system. By reducing system cost and control complexity, the functional output capacity of the system is enhanced, and the application scope of high-frequency WPT is expanded.

[0025] The present invention combines low-frequency topology switching and high-frequency impedance compression methods to propose a high-efficiency, high-power density CC / CV impedance matching network and CC / CV impedance trajectory optimization design theory and flexible impedance connection method to achieve multi-objective simultaneous optimization and improve system functional output performance without wasting the MHz miniaturization advantage. It comprehensively weighs soft switching, CC / CV output, no overshoot, input voltage compression, network parameter integration and device reuse.

[0026] The present invention is also applicable to the field of design of dual-mode impedance trajectory changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the high-frequency wireless battery charging system architecture described in Implementation Example 1.

[0028] Figure 2 This is a schematic diagram of the impedance compression network integration described in Implementation Method 1.

[0029] Figure 3 This is a schematic diagram of the expected performance of the impedance compression network described in Implementation Method 1.

[0030] Figure 4 Schematic diagram of the output performance of the Class-E power amplifier described in Implementation Example 9.

[0031] Figure 5 Schematic diagram of the impedance derivation process flow described in Implementation Method 9.

[0032] Figure 6 This is a schematic diagram of the PA high-efficiency impedance range full utilization constraint result described in Implementation Mode 9.

[0033] Figure 7 This is a schematic diagram of the impedance transformation process of the entire WPT system described in Implementation Mode 9.

[0034] Figure 8This is a flow chart of a design method for a high-frequency wireless battery charging system based on trajectory optimization and matching network integration as described in the eighth implementation mode.

[0035] Fig. 9 This is a schematic diagram of the dual IMN network integration process described in Implementation Example 8.

[0036] Fig. 9 In (a), it is a T-type network X T2 Schematic diagram of integration with series capacitor Ctx, (b) T-type network X T1 Schematic diagram of integration with PA filter inductor, (c) is the schematic diagram of T-type network capacitor device reuse.

[0037] Fig.10 This is a schematic diagram of the high-frequency wireless battery charging system architecture and impedance trajectory based on trajectory optimization and matching network integration as described in Implementation Example 9.

[0038] Fig.10 (a) is a schematic diagram of the totem pole PFC+LLC+WPT system architecture; (b) is a schematic diagram of the CC IMN impedance trajectory; (c) is a schematic diagram of the CV IMN network impedance trajectory; (d) is a schematic diagram of the dual-mode switching IMN network impedance trajectory.

[0039] Fig.11 This is a schematic diagram of an experimental prototype according to Embodiment 9;

[0040] Among them, (a) is the test platform, (b) is the chip used in the circuit; 1 is the input power supply, 2 is the electronic load, 3 is the high-frequency rectifier, 4 is the coupling coil, 5 is the power amplifier, 6 is the auxiliary power supply, and 7 is the oscilloscope.

[0041] Fig.12 This is a schematic diagram of the constant voltage mode CCM test described in actual method nine, wherein (a) is a schematic diagram of the primary side waveform at 30Ω; (b) is a schematic diagram of the secondary waveform at 30Ω; (c) is a schematic diagram of the primary side waveform at 40Ω; and (d) is a schematic diagram of the secondary waveform at 40Ω.

[0042] Fig.13 Schematic diagram of the constant current mode CVM test waveform described in Implementation Example 9, wherein: (a) is the power amplifier PA, a schematic diagram of the coil current at 50Ω; (b) is the rectifier, a schematic diagram of the output voltage and output current at 50Ω; (c) is the power amplifier PA, a schematic diagram of the coil current at 90Ω; (d) is the rectifier, a schematic diagram of the output voltage and output current at 90Ω.

[0043] Fig.14 Schematic diagram of the dual-mode switching process described in Implementation Example 9, wherein (a) is a schematic diagram of normal switching from CCM to CVM; (b) is a schematic diagram of repeated switching and overshoot testing.

[0044] Fig.15 Schematic diagram of the system output power and efficiency curve described in Implementation Mode 9.

[0045] Fig.16 Schematic diagram of the output voltage, output current and input voltage curves of the system described in Implementation Example 9. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the implementation methods of the present application clearer, the technical solutions in the implementation methods of the present application will be clearly and completely described below in conjunction with the drawings in the implementation methods of the present application. Obviously, the described implementation methods are only part of the implementation methods of the present application, not all of the implementation methods.

[0047] Embodiment 1: This embodiment provides a high-frequency wireless battery charging system based on trajectory optimization and matching network integration. The high-frequency wireless battery charging system builds a T-type IMN network based on a constant current mode CCM and a constant voltage mode CVM. The T-type IMN network includes X T1 Impedance and X T2 Impedance, the X T1 Impedance includes L C1 and L V1 , X in the T-type IMN network T1 The impedance is integrated with the output filter resonant inductor L0 of the power amplifier PA and simplified to a single inductor L1; the X T2 Impedance includes L C2 and C V2 , the X T2 Impedance and coil series capacitance C tx Integrated and simplified to a single capacitor C σC1 and C σV1 , the remaining capacitance in the T-type IMN network is used for device reuse.

[0048] Embodiment 2: This embodiment further defines the high-frequency wireless battery charging system based on trajectory optimization and matching network integration described in Embodiment 1. The X T1 The impedance values ​​are equal.

[0049] Implementation method three: This implementation method further limits the high-frequency wireless battery charging system based on trajectory optimization and matching network integration described in implementation method one, and the high-frequency wireless battery charging system also includes a step of switching between constant current mode CCM and constant voltage mode CVM.

[0050] Embodiment 4: This embodiment further limits the multi-task acoustic scene classification method based on efficient parameter fine-tuning described in embodiment 3, and the conversion between the constant current mode CCM and the constant voltage mode CVM is achieved by a double-pole relay.

[0051] Embodiment 5: This embodiment further limits the high-frequency wireless battery charging system based on trajectory optimization and matching network integration described in Embodiment 1. The output filter resonant inductor L0 of the power amplifier PA is also integrated before determining the output impedance Z pa , reflected impedance Z ref , coil input impedance Z coil steps.

[0052] Embodiment 6: This embodiment further limits the high-frequency wireless battery charging system based on trajectory optimization and matching network integration described in Embodiment 1, and the power amplifier PA maintains a soft switching state during the entire charging process.

[0053] Implementation method 7: This implementation method further limits the high-frequency wireless battery charging system based on trajectory optimization and matching network integration described in implementation method 1. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration is obtained by load traction simulation using ADS software.

[0054] Embodiment 8: This embodiment proposes a design method for a high-frequency wireless battery charging system based on trajectory optimization and matching network integration. The design method for a high-frequency wireless battery charging system includes the following steps:

[0055] S1. Determine the load R according to the output requirements of constant current mode CCM and constant voltage mode CVM. Lmin To R Lmax The variation range and maximum power load point R S ;

[0056] S2. Establish the relationship between the rectifier input impedance and the coil efficiency; solve the load R Lmin To R Lmax The limit value of the variation range determines the real component impedance R of the rectifier input impedance rec_opt and peak coil efficiency;

[0057] S3, according to the real component impedance R rec_opt Determine the type of rectifier and parallel capacitor C used r The value of the maximum power load point R S The corresponding rectifier input real impedance R rec Equal to R rec_opt；

[0058] S4, design a dual-mode IMN network;

[0059] S5. Based on the parameters in the dual-mode IMN network used for integration and device reuse, the design of a high-frequency wireless battery charging system integrating trajectory optimization and matching network is completed.

[0060] Embodiment 9: This embodiment provides an example, which is used to explain the above embodiments 1 to 8. The specific example is as follows:

[0061] See also Figures 1 to 16 This embodiment combines the low-frequency charging concept with the high-frequency impedance trajectory to integrate and innovate the unique charging method of the 6.78MHz Class-E system. The basic structure of the system is as follows: Figure 1 shown.

[0062] In order to enhance the functional output of the system, it is important to study the efficient impedance range available for the power amplifier. The classic Class-E circuit is chosen here because of its simple structure, single-ended drive, high efficiency and wide application, such as Figure 4 It is obtained by load-pull simulation using Advanced Design System (ADS) software. The choke characteristics are retained here to reduce the impact on the WPT front-end system. The blue range represents the efficient impedance range of the PA. The power output capability of the PA is defined by the following formula:

[0063]

[0064] Then, we further explore the constraints in the process of using the efficient impedance range. At this time, we need to derive the output impedance Z of the PA. pa Usually, the impedance derivation is carried out step by step from the subsequent circuit to the previous circuit, such as Figure 5 shown.

[0065] First is the input impedance of the full-wave rectifier:

[0066] Z rec =R rec +jX rec (2)

[0067] R rec and X rec They represent the real impedance and imaginary impedance respectively. Next, the reflected impedance Z is derived in turn ref , coil input impedance Z coil and Z pa .

[0068]

[0069] Among them, the intermediate variables in the process are as follows:

[0070]

[0071] like Figure 6 As shown, for PA, on the one hand, it is necessary to maintain soft switching as much as possible throughout the charging process:

[0072]

[0073] On the other hand, the power output requirements of CC / CV mode must be met:

[0074]

[0075] Among them, R Lmin and R Lmax Represent the minimum equivalent load and maximum equivalent load of the battery, R S represents the mode switching load point, η r Represents the overall efficiency of the subsequent stage excluding the PA.

[0076] In addition, there are also requirements for the direction of power change. In constant current mode (CCM), the PA output power should gradually increase, and in constant voltage mode (CVM), the PA output power should gradually decrease, so that the PA power output of each load point in the corresponding mode conforms to the relationship between CC / CV and load. Due to the high-frequency load-related characteristics, it can be described as follows:

[0077]

[0078] At this time Z pa The change of the imaginary part in the impedance trajectory plays a more important role in determining the power direction, and generally meets the following conditions:

[0079]

[0080] Due to the non-resistive conduction problem of the rectifier, for the secondary side, the maximum power point is usually selected for optimal configuration, thereby indirectly improving the efficiency within the entire load variation range. The internal impedance transformation process of the WPT system is as follows: Figure 7 shown.

[0081] Table 1 shows the system parameters.

[0082]

[0083]

[0084] First, determine the load variation range (R Lmin -RLmax ) and the maximum power load point (i.e., mode switching point R S ). Secondly, the specific relationship between the rectifier input impedance and the coil efficiency needs to be established as shown below.

[0085]

[0086] To improve efficiency, complete reactive power elimination is performed at the maximum power point, i.e.

[0087]

[0088] At this point, the coil efficiency can be further simplified and then derived as:

[0089]

[0090] By solving for the limiting values, the optimum real component of the rectifier input impedance and the peak value of the coil efficiency can be determined as shown below.

[0091]

[0092] Therefore, the third step is to calculate the optimal real impedance R rec_opt Determine the type of rectifier and parallel capacitor C used r The value of R S The corresponding rectifier input real impedance R rec Equal to R rec_opt Usually the coil has practical requirements, that is, the coil self-inductance (L tx and L rx ), parasitic resistance (r tx and r rx ) and the coupling coefficient (k) are fixed. Therefore, the series capacitor C tx and C rx The value of can be solved according to (12). Correspondingly, the output impedance Z of the impedance compression network is coil You will get it naturally.

[0093] However, at this time, Z coil The trace cannot meet the CC / CV functional output requirements and is not within the effective impedance range of the PA. Therefore, the fourth step is to design a dual-mode IMN, which includes the following steps:

[0094] 1) Perform IMN design for CCM and CVM respectively. Usually, explicit parameter design and ADS software simulation are required. The goal is to meet the constraints of (7)-(10) and achieve good CC / CV output.

[0095] 2) Let the T-type IMN in CCM and CVM mode X T1The impedance values ​​are equal to facilitate the integration of the subsequent dual-mode IMN. Of course, this will reduce the degree of freedom in the design of the T-type IMN impedance trajectory. Faced with the requirements of full-range ZVS, constant input voltage, and perfect CC / CV output, there may be no corresponding parameter solution at this time. Therefore, it is necessary to appropriately relax the constraints on the input voltage and allow it to change slightly to meet the requirements of other performances.

[0096] 3) Ensure that the dual-mode impedance trace connection is relatively smooth to avoid overshoot during switching. Facing network integration, CC / CV, ZVS and V dc Due to the trade-off between compression, the switching points of the two impedance trajectories may not completely overlap. Again, some compromises can be made to ensure the above performance. Nevertheless, the instantaneous energy states between the switching points of the two modes must be close, as shown below:

[0097]

[0098] The last step is dual-mode IMN parameter integration and device reuse. The dual-stage impedance trajectory design freedom brought by the dual-stage IMN can improve the functional output of the system, but at the cost of increasing the power supply volume and reducing the power density, which to some extent violates the original intention of high-frequency miniaturization. Therefore, the integrated design of the dual-stage IMN is very important. Specifically, Fig. 9 The integrated design process is given. First, the X T2 Impedance(L C2 and C V2 ) and the coil in series with capacitor C tx Integration, simplified to a single capacitor (C σC1 and C σV1 ),like Fig. 9 (a). Secondly, the X T1 Impedance (i.e. L C1 and L V1 , are equal to L σCV ) is integrated with the PA output filter resonant inductor (L0) and simplified to a single inductor (L1), such as Fig. 9 Finally, the remaining capacitance in the T-type IMN is used for device reuse, as shown in Fig. 9 In simple terms, the number of capacitors required for CVM is prioritized as the basic value (C1 and C3), and then the capacitor value required for CCM (C2 and C4) is supplemented through relay switching, thereby reducing the redundancy and waste of capacitor equipment. Fig. 9 (c) shows the final transmitter circuit, which uses only one double-pole relay. The transition from CCM to CVM is accomplished with a single switching operation.

[0099] Traditional static matching networks have the problem of unidirectional compression, and usually cannot naturally achieve the bidirectional change trend of Xpa. For this reason, the traditional solution is static compression plus input voltage regulation, such as Fig.10 As shown in (b) and (c). Fig.10 (b) Taking the CC mode compression network as the core, the impedance trajectory of Zpa during the entire battery charging process is given. It can be clearly seen that when the equivalent load resistance RL is greater than the mode switching point RS, Zpa is out of the efficient working range of the power amplifier and cannot guarantee ZVS. Fig.10 (c) shows the case with CV mode compression network as the core. Although the soft switching characteristics can be maintained during the entire charging process, the cost is that the input voltage fluctuates greatly. For WPT systems, they are often not independent. Their front ends usually include AC / DC circuits or DC / DC circuits, such as the totem pole PFC+LLC two-stage classic topology, such as Fig.10 (a) As is known to all, for LLC circuits, the system efficiency is the highest when it works completely at the resonance point. Therefore, the input voltage (Vdc) change of the subsequent WPT circuit should be compressed as much as possible to reduce the frequency fluctuation of the LLC circuit and better serve the entire power transmission system.

[0100] In order to be compatible with the overall power architecture, WPT subsystem and battery charging load requirements, the solution of the present invention is to change the design of the CC / CV two-stage impedance compression network to make full use of the effective impedance range of the PA. Through functional customization and the change design of the dual-mode impedance trajectory, ZVS and compression of the input voltage change in the whole process can be achieved, such as Fig.10 (d) as shown.

[0101] In order to verify the correctness and feasibility of the theory, a 40W experimental prototype was made to simulate the charging process of a 40V / 1A battery. It is worth noting that the proposed method is a high-frequency universal design concept, which means that it is also applicable to other types of battery parameters, not just 40V / 1A. Fig.11 (a) is the experimental test platform. Fig.11 (b) shows the specific circuits and actual sizes of each part. From left to right, it is the power amplifier PA integrated IMN network, which measures 44mm*42mm, the middle is the rectifier, which measures 42mm*39mm, and the right side is the coupling coil, which measures 120mm*120mm.

[0102] It can be seen that PA and IMN maintain a small size (44mm*42mm), without wasting the advantages of high-frequency miniaturization. It is worth noting that while miniaturizing, it is necessary to avoid overlapping of different PCB networks and reduce unnecessary capacitance between layers. Fixed-mode inductors are used to ensure parameter consistency, and high-precision impedance analyzers are used to reduce parameter errors through repeated testing and simulation. Fig.12 is the test waveform in CCM, where V ds_PA Indicates the inverter switch voltage, V gs_PA Corresponding to its drive. V ds_D1 and V ds_D2 Represents the rectifier diode voltage, I P and I S are the primary and secondary coil currents respectively. out and I out is the system output voltage and current. It can be seen that PA maintains a good soft switching state (driving V gs_PA Before arriving, V ds_PA Although there is a certain reverse conduction time, this is also a trade-off to ensure full range ZVS.

[0103] The primary and secondary coil currents also maintain good sinusoidal characteristics, the secondary side rectifier diode voltage waveform is generally symmetrical (basically no large and small waves), and the energy circulation is small. As the equivalent load increases, the system output voltage gradually increases, but V dc The fluctuation is still small, achieving a good V dc Compression effect. Fig.13 This is the CVM test waveform. It can be seen that as the battery equivalent load increases, the output voltage remains at around 40V and the output current gradually decreases. Near the maximum power point (i.e., 40Ω), the phase difference between the primary and secondary coil current waveforms is close to 90 degrees, achieving good full compensation and reducing the reactive power component. The ZVS characteristics of the PA and the overall symmetry of the rectifier tube are still maintained throughout the constant voltage stage.

[0104] Fig.14 It is a dual-mode instantaneous switching process. Fig.14 (a) Normal CCM to CVM conversion, Fig.14 (b) is a repetitive pulse test, where V signal_relay is the relay drive signal. It can be seen that during the mode switching process, the system does not have obvious overshoot. The switching of the relay does not cause the impact of the surge current, and the input and output voltages (static) and the primary coil current (resonant state) are almost stable, thanks to the preset dual-segment impedance trajectory smooth connection constraint. Fig.15 is the system output power and working efficiency curve, Fig.16 The input and output parameter change curve of the system. The system achieves a good battery charging curve. The input voltage change during the entire charging process is only 3.5V, which is completely within the high efficiency range of the previous DC / DC circuit. At the maximum power point (i.e. the best efficiency optimization point), the system efficiency reaches 90.4%.

[0105] In summary, based on the analysis of the limitations of traditional unidirectional impedance compression, this paper proposes a more advantageous CC / CV IMN integrated design method from the perspective of impedance trajectory optimization. Specifically, it covers the following aspects:

[0106] 1) Analysis of dual-mode IMN parameter design process and integration method

[0107] 2) Introducing multi-device multiplexing mode and dual-mode track connection constraints

[0108] 3) Without wasting the miniaturization advantage of the high-frequency WPT system, an efficient and stable battery charging curve, full-range soft switching, and extreme compression of input voltage changes are achieved.

[0109] The present invention requires no additional cost, is simple to implement, has stable and reliable performance, and has broad application prospects in the field of high-frequency wireless power transmission.

[0110] Figure 8 Any process or method description in the flowchart described in or otherwise described herein can be understood as representing a module, fragment or portion of a code including one or more executable instructions for implementing the steps of a custom logic function or process, and the scope of the preferred embodiment of the present invention includes other implementations, in which the functions may be performed in a substantially simultaneous manner or in a reverse order according to the functions involved, which should be understood by a person skilled in the art of the present invention. The logic and / or steps represented in the flowchart or otherwise described herein illustrate the possible implementation architecture, functions and operations of the apparatus and methods according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for implementing the specified logic function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It is also noted that each block in the block diagram or flowchart, and combinations of blocks in the block diagram or flowchart, may be implemented by a dedicated hardware-based system that performs the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions. For example, what may be considered as an ordered list of executable instructions for implementing a logical function may be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch instructions from and execute instructions in an instruction execution system, apparatus, or device).

[0111] Those skilled in the art will appreciate that the above are only preferred embodiments of the present invention, and the various embodiments of the present disclosure and / or the features described in the claims may be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or perform equivalent substitutions on some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0112] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A high-frequency wireless battery charging system based on trajectory optimization and matching network integration, characterized in that: The high-frequency wireless battery charging system constructs a T-type IMN network based on the constant current mode CCM and the constant voltage mode CVM. The T-type IMN network includes X T1 Impedance and X T2 Impedance, the X T1 Impedance includes L C1 and L V1 , X in the T-type IMN network T1 The impedance is integrated with the output filter resonant inductor L0 of the power amplifier PA and simplified to a single inductor L 1； The X T2 Impedance includes L C2 and C V2 , the X T2 Impedance and coil series capacitance C tx Integrated and simplified to a single capacitor C σC1 and C σV1 , the remaining capacitance in the T-type IMN network is used for device reuse.

2. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration according to claim 1 is characterized in that: The constant current mode CCM and constant voltage mode CVM mode X T1 The impedance values ​​are equal.

3. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration according to claim 1 is characterized in that: The high frequency wireless battery charging system also includes a step of switching between a constant current mode (CCM) and a constant voltage mode (CVM).

4. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration according to claim 3 is characterized in that: The constant current mode CCM and the constant voltage mode CVM conversion is achieved through a double-pole relay.

5. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration according to claim 1 is characterized in that: The output filter resonant inductor L0 of the power amplifier PA is integrated before the output impedance Z is determined. pa , reflected impedance Z ref , coil input impedance Z coil steps.

6. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration according to claim 1 is characterized in that: The power amplifier PA maintains a soft switching state during the entire charging process.

7. The high-frequency wireless battery charging system based on trajectory optimization and matching network integration according to claim 1 is characterized in that: The high-frequency wireless battery charging system based on trajectory optimization and matching network integration is obtained by load traction simulation using ADS software.

8. A design method for a high-frequency wireless battery charging system based on trajectory optimization and matching network integration, characterized in that: The design method of the high-frequency wireless battery charging system comprises the following steps: S1. Determine the load R according to the output requirements of constant current mode CCM and constant voltage mode CVM. Lmin To R Lmax The variation range and maximum power load point R S ; S2. Establish the relationship between the rectifier input impedance and the coil efficiency; solve the load R Lmin To R Lmax The limit value of the variation range determines the real component impedance R of the rectifier input impedance rec_opt and peak coil efficiency; S3, according to the real component impedance R rec_opt Determine the type of rectifier and parallel capacitor C used r The value of the maximum power load point R S The corresponding rectifier input real impedance R rec Equal to R rec_opt ; S4, design a dual-mode IMN network; S5. Based on the parameters in the dual-mode IMN network used for integration and device reuse, the design of a high-frequency wireless battery charging system integrating trajectory optimization and matching network is completed.

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