Wireless charging system constant power output control method based on parameter sensitivity analysis

Abstract

The invention provides a wireless charging system constant power output control method based on parameter sensitivity analysis, and the method comprises the steps: obtaining the transmitting-receiving end parameter information of a wireless charging system, and carrying out the exchange of the transmitting-receiving end parameter information; determining target output power according to the transmitting-receiving end parameter information; coupling coil mutual inductance is identified, a mutual inductance offset proportion and a switch tube conduction phase angle of the switch control capacitor are calculated, and a phase control capacitor switch duty ratio of the switch control capacitor is set; outputting the constant power of the wireless charging system according to the calculation and setting results; judging whether the output power meets the requirement or not; if yes, the setting and calculation processes are executed again at set time intervals, and whether the output power meets the requirement or not continues to be judged till current power output control is completed; and if the output power does not meet the requirement, directly resetting the setting and calculation process until the output power meets the requirement. According to the invention, constant power output of the system under a variable coupling coefficient condition is realized.

Description

Technical Field

[0001] The present invention relates to the field of wireless power transmission technology, and in particular to a constant power output control method for a wireless charging system based on parameter sensitivity analysis, as well as a corresponding system, a computer terminal, and a computer-readable storage medium. Background Art

[0002] The advent of electric vehicles has driven the development of efficient and reliable wireless charging systems. Currently, inductive power transfer (IPT) technology is the mainstream solution for wireless charging systems for electric vehicles. The compensation network, a key component in IPT systems used to address the inherent low power factor of loosely coupled coils, has become an indispensable component because it effectively reduces the system's capacity requirements and improves operating efficiency. Among various compensation topologies, the LCC-LCC compensation network has become a highly promising solution for electric vehicle applications due to its low component voltage / current stress, inherent ability to achieve load-independent constant current output, and excellent design flexibility.

[0003] However, similar to other compensation topologies, the LCC-LCC compensation network exhibits significant sensitivity to deviations in the coil coupling coefficient, which can have a significant impact on the system's output characteristics. The performance of wireless charging systems is highly sensitive to the parameters of the compensation network components, and the equivalent parameters of these components may shift due to environmental and operational factors such as temperature changes, aging, and corrosion. This parameter shift phenomenon can disrupt the system's resonant state, causing fluctuations in the system's transmission performance and efficiency. Therefore, the field urgently needs to propose a systematic, low-cost, constant power output control technology for wireless charging systems that is seamlessly compatible with existing systems. Currently, no descriptions or reports of technologies similar to the present invention have been found, and no similar information has been collected domestically or internationally. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention aims to provide a constant power output control method for a wireless charging system based on parameter sensitivity analysis, and also provides a corresponding system, a computer terminal and a computer-readable storage medium.

[0005] According to a first aspect of the present invention, a method for controlling constant power output of a wireless charging system based on parameter sensitivity analysis is provided, comprising:

[0006] S1, obtaining the transceiver parameter information of the wireless charging system and exchanging the transceiver parameter information;

[0007] S2, determining the target output power based on the transmit and receive end parameter information;

[0008] S3, identifying the mutual inductance of the coupled coil, calculating the mutual inductance offset ratio γ and the conduction phase angle α of the switch-controlled capacitor, and setting the phase-controlled capacitor switch duty cycle of the switch-controlled capacitor;

[0009] S4, outputting a constant power of the wireless charging system according to the result calculated and set in S3;

[0010] S5, determines whether the output power meets the demand; if so, re-execute S3 and S4 after a set time, and continue to determine whether the output power meets the demand until the current power output control is completed; if not, directly re-execute S3 and S4 until the output power meets the demand.

[0011] According to a second aspect of the present invention, a constant power output control system for a wireless charging system based on parameter sensitivity analysis is provided, comprising:

[0012] A parameter information acquisition module, which is used to obtain the parameter information of the wireless charging system transceiver and exchange the parameter information of the transceiver;

[0013] A target power calculation module, which is used to determine the target output power based on the parameter information of the transmitting and receiving ends;

[0014] A parameter setting module is used to identify the mutual inductance of the coupled coil, calculate the mutual inductance offset ratio γ and the conduction phase angle α of the switch-controlled capacitor switch, and set the phase-controlled capacitor switch duty cycle of the switch-controlled capacitor;

[0015] A constant power calculation module, which is used to output the constant power of the wireless charging system according to the results calculated and set by the parameter setting module;

[0016] The logic judgment module is used to judge whether the output power meets the requirements. If so, the parameter setting module and the constant power calculation module are re-executed after a set time, and the judgment on whether the output power meets the requirements is continued until the current power output control is completed. If not, the parameter setting module and the constant power calculation module are directly re-executed until the output power meets the requirements.

[0017] According to a third aspect of the present invention, a computer terminal is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the terminal can be used to execute the method described above in the present invention, or to execute the system described above in the present invention.

[0018] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it can be used to execute the method described above in the present invention, or to run the system described above in the present invention.

[0019] Due to the adoption of the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0020] The constant power output control method for a wireless charging system based on parameter sensitivity analysis provided by the present invention improves only one component of the compensation network of the wireless charging system, thereby reducing the complexity of system control while also lowering the hardware cost requirement.

[0021] The constant power output control method for a wireless charging system based on parameter sensitivity analysis provided by the present invention only improves the transmitting stage of the wireless charging system and does not require changes to the receiving stage circuit. Therefore, it can be directly applied to the existing electric vehicle wireless charging architecture and has high interoperability.

[0022] The constant power output control method for a wireless charging system based on parameter sensitivity analysis provided by the present invention provides a numerical calculation method for the conduction phase angle of the switching tube corresponding to a specific adjustment scheme. Therefore, when the output accuracy requirement is not high, closed-loop control is not required, reducing the system's R&D costs.

[0023] The constant power output control method for a wireless charging system based on parameter sensitivity analysis provided by the present invention can be directly applied to the existing wireless charging architecture of electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0025] Figure 1 4 is a flowchart of a constant power output control method for a wireless charging system based on parameter sensitivity analysis in a preferred embodiment of the present invention.

[0026] Figure 2 This is a topological diagram of a resistive load IPT system with LCC-LCC compensation in a specific application example of the present invention.

[0027] Figure 3 This is a simplified topology diagram of a resistive load IPT system with LCC-LCC compensation that only considers the fundamental component in a specific application example of the present invention.

[0028] Figure 4 This is a schematic diagram of the relationship between the system output power and transmission efficiency as the parameter offset coefficients of each parameter are changed under the conditions of the transmitting and receiving end parameters in a specific application example of the present invention; wherein, (a) is a schematic diagram of the relationship between the system output power and the parameter offset coefficients, and (b) is a schematic diagram of the relationship between the system transmission efficiency and the parameter offset coefficients.

[0029] Figure 51 is a topology diagram of a constant output power circuit in a specific application example of the present invention; wherein (a) is the topology diagram of the proposed constant output power circuit, and (b) is the circuit structure of the adopted SCC.

[0030] Figure 6 This is an application effect diagram of the constant power output control method in a specific application example of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0032] To address the problem in the prior art of the lack of a systematic, low-cost constant power output control technology for wireless charging systems that is seamlessly compatible with existing systems, one embodiment of the present invention provides a constant power output control method for wireless charging systems based on parameter sensitivity analysis. This method uses parameter sensitivity analysis to identify the compensation element with the greatest impact on the system output, and uses phase-controlled capacitors to control its equivalent impedance to achieve constant power output of the system under variable coupling coefficient conditions, thereby improving the system transmission performance.

[0033] Specifically, if Figure 1 As shown, the constant power output control method of the wireless charging system based on parameter sensitivity analysis provided in this embodiment may include:

[0034] S1, obtaining the transceiver parameter information of the wireless charging system and exchanging the transceiver parameter information;

[0035] S2, determining the target output power based on the transmit and receive end parameter information;

[0036] S3, identifying the mutual inductance of the coupled coil, calculating the mutual inductance offset ratio γ and the switch-controlled capacitor switch conduction phase angle α, and setting the phase-controlled capacitor switch duty cycle of the switch-controlled capacitor;

[0037] S4, outputting a constant power of the wireless charging system according to the result calculated and set in S3;

[0038] S5, determines whether the output power meets the demand (i.e., whether it meets the target output power); if so, re-execute S3 and S4 after a set time, and continue to determine whether the output power meets the demand until the current power output control is completed; if not, directly re-execute S3 and S4 until the output power meets the demand.

[0039] In some preferred implementations, the above S1, obtaining the transmitting and receiving end parameter information, may further include:

[0040] The wireless charging system adopts a bilateral LCC wireless charging system. The transceiver parameter information of the bilateral LCC wireless charging system includes:

[0041] DC side voltage U of the emitter dc , filter capacitor C on the output side of the receiving stage O , the resonant inductor L1 of the transmitter, the parallel resonant capacitor C of the transmitter p1 , the series resonant capacitor C of the transmitter f1 , the resonant inductor L2 of the receiving stage, the parallel resonant capacitor C of the receiving stage p2 , the series resonant capacitor C of the receiving stage f2 , the self-inductance L of the transmitting coil and the receiving coil p and L s , the mutual inductance M between the transmitting coil and the receiving coil;

[0042] The output current of the transmitter-stage inverter and the input currents i1 and i2 of the receiver-stage rectifier;

[0043] The current i flowing in the transmitting coil and the receiving coil p and i s .

[0044] In some preferred implementations, the above S1, exchanging the parameter information of the transmitting and receiving ends, may further include:

[0045] Through the communication channel established by the transceiver, the receiving stage sends its parameter information to the transmitting stage through the communication channel; wherein the parameter information includes: the resonant inductor L2 of the receiving stage, the parallel resonant capacitor C of the receiving stage p2 , the series resonant capacitor C of the receiving stage f2 and the self-inductance L of the receiving coil s .

[0046] In some preferred embodiments, the above S2, determining the target output power according to the transceiver parameter information, may further include:

[0047] S21, transmission power P of bilateral LCC wireless charging system o The expression is:

[0048]

[0049] Where M is the mutual inductance between the transmitting coil and the receiving coil; R is the load resistance R L The equivalent resistance before the passive rectifier bridge, U AB is the DC voltage U dcThe equivalent voltage after the inverter; ω0 is the resonant angular frequency of the system, L1 is the resonant inductance of the transmitter stage, and L2 is the resonant inductance of the receiver stage;

[0050] S22, set the parallel resonant capacitor C of the transmitter p1 The capacitance value of is changed to λ1 times of the resonant value, and the parameters of other compensation components do not shift, then the parameter relationship between the transmitter and receiver becomes:

[0051]

[0052] Where, L1 is the resonant inductor of the transmitter; L2 is the resonant inductor of the receiver; C p2 is the parallel resonant capacitor of the receiving stage; L p is the self-inductance of the transmitting coil; L s is the self-inductance of the receiving coil; C f1 is the series resonant capacitor of the transmitter; C f2 is the series resonant capacitor of the receiving stage;

[0053] S23, accordingly, the loop equation becomes:

[0054]

[0055] Where, is the parallel resonant capacitor C of the transmitter p1 Input current phasor in offset condition; is the parallel resonant capacitor C of the transmitter p1 Transmitter coil current phasor under offset conditions; is the parallel resonant capacitor C of the transmitter p1 Output current phasor in offset condition; is the parallel resonant capacitor C of the transmitter p1 Receive coil current phasor under offset conditions; is the input voltage phasor;

[0056] S24, the current phasor in the compensation network is expressed as:

[0057]

[0058] S25, the system's output power P out_cp1 for:

[0059]

[0060] Where, I 2_cp is the parallel resonant capacitor C of the transmitter p1 The effective value of the output current under offset conditions;

[0061] The power loss due to the internal resistance and switching loss of S26, MOSFET and diode is calculated as:

[0062]

[0063] S27, total loss of the system P loss_tot_cp1 And the transmission efficiency η is calculated as:

[0064]

[0065] Where, P loss_coil_cp1 is the parallel resonant capacitor C of the transmitter p1 Coil internal resistance parasitic loss under offset conditions; P loss_L_cp1 is the parallel resonant capacitor C of the transmitter p1 Compensation inductor internal resistance parasitic loss under offset conditions; P loss_mos_cp1 is the parallel resonant capacitor C of the transmitter p1 The loss generated in the MOSFET switch tube under offset conditions; P loss_diode_cp is the parallel resonant capacitor C of the transmitter p1 The losses incurred in the diode during offset conditions.

[0066] In some preferred embodiments, the above S3, identifying the mutual inductance of the coupled coils, calculating the mutual inductance offset ratio γ and the switch conduction phase angle α, and setting the phase-controlled capacitor switch duty cycle, may further include:

[0067] S31, assuming that the coupling coefficient changes due to coil offset, and the mutual inductance M is proportionally adjusted according to the mutual inductance offset ratio (scaling factor) γ, then in order to maintain a constant output power, λ1 is adjusted accordingly to:

[0068]

[0069] Where f(γ) is the parallel resonant capacitor C of the transmitter p1 The offset coefficient λ1 is expressed as a function of the mutual inductance offset ratio γ;

[0070] S32, the switch control capacitor adopts SCC switch control capacitor, which includes a fixed capacitor C p0 and two MOSFET switches S a and S b , then the equivalent capacitance of the switch control capacitor SCC is regulated according to the switch state:

[0071]

[0072] Where C scc is the equivalent capacitance of SCC; α is the switching tube S a The conduction phase angle.

[0073] In the above preferred embodiment, the mutual inductance offset ratio γ is defined as the proportional relationship between the real-time mutual inductance after the offset and the mutual inductance reference value at the time of design. Therefore, after identifying the real-time mutual inductance of the coupled coil, it can be immediately obtained by dividing it by the mutual inductance reference value in the parameter information; the phase angle α can be calculated using the following formula.

[0074] In some preferred embodiments, the above S4, outputting the constant power of the wireless charging system according to the result of calculation and setting in S3, may further include:

[0075] By regulating the switch tube S a The conduction phase angle α can adjust the parallel resonant capacitor C of the transmitter stage. p1 The equivalent capacitance value of , so that the system can achieve constant power output:

[0076]

[0077] Where, Indicates the process of deducing from the former to the latter; g(γ) is the process of The equations above are derived and solved, and the parallel resonant capacitor C of the transmitter is p1 The offset coefficient λ1 is expressed as a function of the mutual inductance offset ratio γ;

[0078] The specific implementation principle and implementation process of the method for designing the resonant frequency and resonant network parameters of the underwater wireless charging system provided by the above embodiment of the present invention are further described in detail below.

[0079] The IPT systems used in the above embodiments of the present invention all use LCC-LCC compensation networks, such as Figure 2 As shown. Among them, U dc Represents the DC side voltage of the transmitter stage. S1~S4 and D1~D4 constitute the full-bridge inverter circuit and passive rectifier circuit of the transmitter stage and the receiver stage respectively. C O It is the filter capacitor on the output side of the receiving stage. L1 is the resonant inductor of the transmitting stage, C p1 is the parallel resonant capacitor of the transmitter stage, C f1 is the series resonant capacitor of the transmitter stage, and the three form the compensation network of the transmitter stage; L2 is the resonant inductor of the receiver stage, C p2 is the parallel resonant capacitor of the receiving stage, C f2 It is the series resonant capacitor of the receiving stage, and the three constitute the compensation network of the receiving stage. p and L s are the self-inductance of the transmitting coil and the receiving coil respectively, and M is the mutual inductance between the two.

[0080] Due to the strong filtering effect of the LCC resonant network, the current flowing through the transmission coil contains almost only the fundamental component, and the power transmission between the primary and secondary sides is mainly achieved by the fundamental component. Therefore, only the fundamental component is considered in the subsequent analysis. The simplified topology of the wireless charging system based on the LCC-LCC compensation network is as follows: Figure 3 As shown. i1 and i2 represent the output current of the transmitter inverter and the input current of the receiver rectifier respectively. p and i s In this specification, bold uppercase italic letters indicate vector quantities, uppercase italic letters with a dot above them indicate phasors, uppercase italic letters indicate effective values ​​of DC and AC quantities, and lowercase italic letters indicate instantaneous values.

[0081] To achieve zero phase angle (ZPA), the resonant frequencies of the transmitter and receiver compensation networks must be consistent and match the system's operating frequency. The system's resonant angular frequency is equal to ω0 = 2πf0, and the parameters of the bilateral LCC compensation network must meet the following requirements:

[0082]

[0083] exist Figure 3 Under the given voltage and current reference directions, ignoring the influence of component parasitic resistance, according to Kirchhoff's law and combined with the resonance relationship in formula (1), the loop equation can be obtained as follows:

[0084]

[0085] Solving the loop equation, we can get the expression of the current in each mesh:

[0086]

[0087] Therefore, the transmission power expression of the bilateral LCC wireless charging system is:

[0088]

[0089] Assumption C p1 The capacitance value of the resonant element is changed to λ1 times of the resonant value, and the parameters of the other compensation components do not shift. Then the parameter relationship of the resonant component becomes:

[0090]

[0091] Correspondingly, the loop equation becomes:

[0092]

[0093] The subscript "cp1" indicates C p1The current phasor in the compensation network can be expressed as follows:

[0094]

[0095] Since the output side of the compensation network is connected to a resistive load, the output power of the system is:

[0096]

[0097] By analyzing the current phasor, the transmission loss, output power and operating efficiency of the system can be analyzed and determined. Under the actual working conditions where MOSFETs achieve zero voltage turn-on, their turn-on losses can be ignored due to their soft switching characteristics, while the turn-off losses and conduction losses can be clearly quantified. In the full-bridge inverter structure, the two MOSFETs from the opposite bridge arms operate in a complementary conduction state in each switching cycle, and the rectifier side also maintains the current passing through the two diodes in each operating cycle. The power loss caused by the internal resistance and switching loss of the MOSFET and diode is shown in (9), where r coil_p and r coil_s Represent the internal resistance of the transmitting coil and the receiving coil, r L1 and r L2 Represent the internal resistance of L1 and L2 respectively. mos is the on-resistance of the MOSFET, E off is the turn-off loss of the MOSFET under test conditions. V DS and I D This is the test condition for testing MOSFET turn-off loss. f Indicates the forward voltage of the diode.

[0098]

[0099] Then, the total loss and transmission efficiency of the system can be calculated as:

[0100]

[0101] By using similar analysis methods, the transmission characteristics and loss model of the system under other compensation component parameter deviations can be derived. Limiting the component parameter offset coefficient to the range of 0.9 to 1.1, using the prototype parameters of the application example, the relationship between output power, efficiency and component offset coefficient is as follows: Figure 3 As shown. Figure 4 As shown in (a) and (b), the impact of all parameter deviations on system efficiency is within an acceptable range, but compared with other resonant network parameters, the capacitor C p1 and C p2It has a more significant impact on the output power, and the correlation shows a monotonic change characteristic. Based on the engineering requirements of simplifying the design of vehicle circuits, the C p1 Achieve stable control of output power.

[0102] Assuming the coupling coefficient changes due to coil offset, the mutual inductance M is proportionally adjusted by the scaling factor γ. To maintain a constant output power, λ1 needs to be adjusted accordingly to:

[0103]

[0104] To achieve C p1 Dynamic adjustment of equivalent capacitance value is done by Figure 5 The switch-controlled capacitor (SCC) topology shown in (a) and (b) is an alternative. The SCC configuration consists of a fixed capacitor C p0 With two MOSFET switches S a 、S b The equivalent capacitance value can be adjusted according to the switch state:

[0105]

[0106] Among them, α represents the switch tube S a Therefore, by adjusting the α parameter, C p1 The equivalent capacitance value enables the system to achieve constant power output according to:

[0107]

[0108] The above mutual inductance offset ratio γ is defined as the proportional relationship between the real-time mutual inductance after offset and the mutual inductance reference value at the time of design. Therefore, after identifying the real-time mutual inductance of the coupled coil, it can be immediately obtained by dividing it by the mutual inductance reference value in the parameter information. The phase angle α can be calculated using formula (13).

[0109] To ensure direct applicability to existing electric vehicle wireless charging architectures, the constant-power output control method for a wireless charging system provided in the aforementioned embodiments achieves stable output characteristics by dynamically adjusting the equivalent parameters of the compensation network. In practice, by strategically leveraging parameter sensitivity analysis results to focus on key parameters that significantly influence system output, uncontrollable parameter offsets can be converted into controllable parameter adjustments, enabling wide-range output regulation and ultimately achieving stable system output at a low cost.

[0110] The constant power output control method for a wireless charging system provided in the above-mentioned embodiments of the present invention uses sensitivity analysis to identify the compensation network component that has the greatest impact on system output, and then achieves constant power output by controlling the equivalent impedance of this component. This method also further investigates the impact of parameter offsets of various compensation components on system output power and transmission efficiency in an LCC-LCC compensated wireless charging system. The compensation component with the greatest impact on system output performance is identified and replaced with a controllable component. By leveraging this impact on system output performance, the equivalent impedance of this component is adjusted accordingly when the system coil coupling coefficient changes, achieving constant power output under variable coupling coefficient conditions.

[0111] The above-described embodiments of the present invention provide a method for controlling constant power output in a wireless charging system. By replacing the compensation element in a traditional LCC-LCC compensation network, which has the greatest impact on system output performance, with a phase-controlled element, the method then modulates the equivalent impedance of this element to achieve constant power output under variable coupling coefficient conditions. This method is easy to implement, relatively low in cost and control complexity, and compatible with existing systems.

[0112] Based on the same inventive concept, an embodiment of the present invention further provides a constant power output control system for a wireless charging system based on parameter sensitivity analysis.

[0113] Specifically, the wireless charging system constant power output control system based on parameter sensitivity analysis provided in this embodiment may include:

[0114] A parameter information acquisition module, which is used to obtain the parameter information of the wireless charging system transceiver and exchange the parameter information of the transceiver;

[0115] A target power calculation module, which is used to determine the target output power based on the parameter information of the transmitting and receiving ends;

[0116] A parameter setting module is used to identify the mutual inductance of the coupled coil, calculate the mutual inductance offset ratio γ and the conduction phase angle α of the switch-controlled capacitor switch, and set the phase-controlled capacitor switch duty cycle of the switch-controlled capacitor;

[0117] A constant power calculation module, which is used to output the constant power of the wireless charging system according to the results calculated and set by the parameter setting module;

[0118] The logic judgment module is used to judge whether the output power meets the requirements. If so, the parameter setting module and the constant power calculation module are re-executed after a set time, and the judgment on whether the output power meets the requirements is continued until the current power output control is completed. If not, the parameter setting module and the constant power calculation module are directly re-executed until the output power meets the requirements.

[0119] It should be noted that the steps in the method provided by the present invention can be implemented using corresponding modules, devices, units, etc. in the system. Those skilled in the art can refer to the technical solution of the method to implement the composition of the system, that is, the embodiments in the method can be understood as preferred examples of constructing the system, which will not be elaborated here.

[0120] The technical solution provided by the above embodiment of the present invention is further described in detail below with reference to a specific application example.

[0121] In this specific application example, the parameters of the transmitting and receiving ends are set as follows:

[0122] Primary DC voltage U dc : 150V;

[0123] System resonant frequency f0: 85kHz

[0124] Transmitting coil self-inductance L p :130.25μH;

[0125] Receiving coil self-inductance L s :92.22μH;

[0126] Coil mutual inductance M: 28.39μH;

[0127] Transmitter compensation inductor L1: 23.5μH;

[0128] Receiver compensation inductor L2: 23.5μH;

[0129] Transmitter parallel compensation capacitor C p1 : 149.19nF;

[0130] Receiving end parallel compensation capacitor C p2 : 149.19nF;

[0131] Transmitter series compensation capacitor C f1 : 32.84nF;

[0132] Receiving end series compensation capacitor C f2 :51.02nF;

[0133] Load resistance R L :10Ω;

[0134] Transmitting coil internal resistance R coil_p :0.3Ω;

[0135] Receiving coil internal resistance R coil_s :0.15Ω;

[0136] Primary compensation inductor internal resistance R fL1 :0.03Ω;

[0137] Secondary side compensation inductor internal resistance R fL2 :0.03Ω;

[0138] MOSFET's on-state internal resistance R mos :0.03Ω;

[0139] MOSFET turn-off loss E under test conditions off :204μJ;

[0140] MOSFET turn-off loss test voltage V DS : 600V;

[0141] MOSFET turn-off loss test current I D :27A;

[0142] The forward voltage of the diode V f : 1.4V.

[0143] During the experiment, the input voltage, load resistance, and operating frequency were kept constant, and perturbations of ±20%, ±10%, -10%, and -20% were applied to the transmission distance. Under these conditions, the system voltage / current parameters were systematically monitored and recorded, and the input / output power was calculated based on them. The experimental results show that the transmission distance and output power are significantly negatively correlated: increasing the distance leads to a decrease in output power, while decreasing the distance leads to an increase in output power. Figure 6 As shown in the figure, the proposed control strategy significantly suppresses the dependence of power and distance, limiting output power fluctuations to within ±20W within a ±20% transmission distance variation. This strategy stabilizes the output power within a 2.5% deviation range, effectively verifying its effectiveness in compensating for coupling variations.

[0144] The implementation process first exchanges parameters between the transmitter and receiver. An information channel must be established to exchange key system parameters such as battery voltage, compensation parameters, and internal resistance. The user then determines the output power based on multiple factors, taking into account component voltage / current stress limits, compensation network parameter constraints, and vehicle-side battery power requirements. Mutual inductance identification is then performed: the receiver is short-circuited, and the transmitter injects a controlled current I p , by real-time monitoring of the transmitter voltage V AB and the receiving end current I s The mutual inductance M can be calculated.

[0145] After obtaining the above parameters, the mutual inductance offset coefficient γ is calculated and the control parameter α is derived according to Equation (13). This parameter dominates the operating state of the SCC. If the output power does not meet the requirements, the mutual inductance identification process must be re-executed. When the operating conditions are met, mutual inductance verification should be performed periodically to compensate for changes in environmental factors.

[0146] An embodiment of the present invention further provides a computer terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the computer terminal can be used to execute the above-mentioned method of the present invention, or to execute the above-mentioned system of the present invention.

[0147] Optionally, the memory is used to store programs; the memory may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviated: RAM), such as static random-access memory (English: static random-access memory, abbreviated: SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviated: DDR SDRAM), etc.; the memory may also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory is used to store computer programs (such as applications, functional modules, etc. that implement the above-mentioned methods), computer instructions, etc., and the above-mentioned computer programs, computer instructions, etc. can be partitioned and stored in one or more memories. In addition, the above-mentioned computer programs, computer instructions, data, etc. can be called by the processor.

[0148] The processor is configured to execute the computer program stored in the memory to implement the various steps of the method or various modules of the system involved in the above embodiments. For details, please refer to the relevant descriptions in the above method and system embodiments.

[0149] The processor and memory can be independent structures or integrated structures. When the processor and memory are independent structures, the memory and processor can be coupled via a bus.

[0150] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it can be used to execute the above-mentioned method of the present invention, or to run the above-mentioned system of the present invention.

[0151] Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of computer programs from one location to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC. Alternatively, the ASIC can be located in a user device. Of course, the processor and storage medium can also exist as discrete components in a communication device.

[0152] The above-described embodiments of the present invention provide a method for controlling constant power output in a wireless charging system based on parameter sensitivity analysis. This method uses sensitivity analysis to identify the compensation network component with the greatest impact on system output, and then controls the equivalent impedance of this component to achieve constant power output. By thoroughly studying the impact of parameter offsets of various compensation components on system output power and transmission efficiency in an LCC-LCC compensated wireless charging system, the compensation component with the greatest impact on system output performance is identified and replaced with a controllable component. By leveraging this impact on system output performance, the equivalent impedance of this component is adjusted accordingly when the system coil coupling coefficient changes, achieving constant power output under variable coupling coefficient conditions.

[0153] Matters not mentioned in the above embodiments of the present invention are well known in the art.

[0154] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A constant power output control method for a wireless charging system based on parameter sensitivity analysis, characterized in that: include: S1, obtaining the transceiver parameter information of the wireless charging system and exchanging the transceiver parameter information; S2, determining the target output power based on the transmit and receive end parameter information; S3, identifying the mutual inductance of the coupled coil, calculating the mutual inductance offset ratio γ and the switch-controlled capacitor switch conduction phase angle α, and setting the phase-controlled capacitor switch duty cycle of the switch-controlled capacitor; S4, outputting a constant power of the wireless charging system according to the result calculated and set in S3; S5, determines whether the output power meets the demand; if so, re-execute S3 and S4 after a set time, and continue to determine whether the output power meets the demand until the current power output control is completed; if not, directly re-execute S3 and S4 until the output power meets the demand.

2. The constant power output control method for a wireless charging system based on parameter sensitivity analysis according to claim 1, characterized in that: The obtaining of the wireless charging system transceiver parameter information includes: The wireless charging system adopts a bilateral LCC wireless charging system. The transceiver parameter information of the bilateral LCC wireless charging system includes: DC side voltage U of the emitter dc , filter capacitor C on the output side of the receiving stage O , the resonant inductor L1 of the transmitter, the parallel resonant capacitor C of the transmitter p1 , the series resonant capacitor C of the transmitter f1 , the resonant inductor L2 of the receiving stage, the parallel resonant capacitor C of the receiving stage p2 , the series resonant capacitor C of the receiving stage f2 , the self-inductance L of the transmitting coil and the receiving coil p and L s , the mutual inductance M between the transmitting coil and the receiving coil; The output current of the transmitter-stage inverter and the input currents i1 and i2 of the receiver-stage rectifier; The current i flowing in the transmitting coil and the receiving coil p and i s .

3. The constant power output control method for a wireless charging system based on parameter sensitivity analysis according to claim 2, characterized in that: The exchanging of the transmitting and receiving end parameter information includes: Through the communication channel established by the transceiver, the receiving stage sends its parameter information to the transmitting stage through the communication channel; wherein, the parameter information includes: the resonant inductor L2 of the receiving stage, the parallel resonant capacitor C of the receiving stage p2 , the series resonant capacitor C of the receiving stage f2 and the self-inductance L of the receiving coil s .

4. The constant power output control method for a wireless charging system based on parameter sensitivity analysis according to claim 1, characterized in that: The determining the target output power according to the transceiver parameter information includes: Transmission power P of bilateral LCC wireless charging system o The expression is: Where M is the mutual inductance between the transmitting coil and the receiving coil; R is the load resistance R L The equivalent resistance before the passive rectifier bridge, U AB is the DC voltage U dc The equivalent voltage after the inverter; ω0 is the resonant angular frequency of the system, L1 is the resonant inductance of the transmitter stage, and L2 is the resonant inductance of the receiver stage; Assume that the parallel resonant capacitor C of the transmitter p1 The capacitance value of is changed to λ1 times of the resonant value, and the parameters of other compensation components do not shift, then the parameter relationship between the transmitter and receiver becomes: Where, L1 is the resonant inductor of the transmitter; L2 is the resonant inductor of the receiver; C p2 is the parallel resonant capacitor of the receiving stage; L p is the self-inductance of the transmitting coil; L s is the self-inductance of the receiving coil; C f1 is the series resonant capacitor of the transmitter; C f2 is the series resonant capacitor of the receiving stage; Accordingly, the loop equation becomes: Where, is the parallel resonant capacitor C of the transmitter p1 Input current phasor in offset condition; is the parallel resonant capacitor C of the transmitter p1 Transmitter coil current phasor under offset conditions; is the parallel resonant capacitor C of the transmitter p1 Output current phasor in offset condition; is the parallel resonant capacitor C of the transmitter p1 Receive coil current phasor under offset conditions; is the input voltage phasor; The current phasor in the compensation network is expressed as: The system's output power P out_cp1 for: Where, I 2_cp1 is the parallel resonant capacitor C of the transmitter p1 The effective value of the output current under offset conditions; The power loss due to the internal resistance and switching loss of the MOSFET and diode is calculated as: The total loss of the system P loss_tot_cp1 And the transmission efficiency η is calculated as: Where, P loss_coil_cp is the parallel resonant capacitor C of the transmitter p1 Coil internal resistance parasitic loss under offset conditions; P loss_L_cp1 is the parallel resonant capacitor C of the transmitter p1 Compensation inductor internal resistance parasitic loss under offset conditions; P loss_mos_cp1 is the parallel resonant capacitor C of the transmitter p1 The loss generated in the MOSFET switch tube under offset conditions; P loss_diode_cp1 is the parallel resonant capacitor C of the transmitter p1 The losses incurred in the diode during offset conditions.

5. The constant power output control method for a wireless charging system based on parameter sensitivity analysis according to claim 1, characterized in that: The identification of the mutual inductance of the coupled coils, calculation of the mutual inductance offset ratio γ and the switch conduction phase angle α, and setting the phase-controlled capacitor switch duty cycle include: Assume that the coupling coefficient changes due to the coil offset, and the mutual inductance M is proportionally adjusted according to the mutual inductance offset ratio γ. In order to maintain a constant output power, λ1 is adjusted accordingly to: Where f(γ) is the parallel resonant capacitor C of the transmitter p1 The offset coefficient λ1 is expressed as a function of the mutual inductance offset ratio γ; The switch control capacitor adopts SCC switch control capacitor, which includes a fixed capacitor C p0 and two MOSFET switches S a and S b , then the equivalent capacitance of the switch control capacitor SCC is regulated according to the switch state: Where C scc is the equivalent capacitance of SCC; α is the switching tube S a The conduction phase angle.

6. The constant power output control method for a wireless charging system based on parameter sensitivity analysis according to claim 1, characterized in that: Outputting the constant power of the wireless charging system according to the result of calculation and setting in S3 includes: By regulating the switch tube S a The conduction phase angle α can adjust the parallel resonant capacitor C of the transmitter stage. p1 The equivalent capacitance value of , so that the system can achieve constant power output: Where, Indicates the process of deducing from the former to the latter; g(γ) is the process of The equations above are derived and solved, and the parallel resonant capacitor C of the transmitter is p1 The offset coefficient λ1 is expressed as a function of the mutual inductance offset ratio γ.

7. A constant power output control system for a wireless charging system based on parameter sensitivity analysis, characterized in that: include: A parameter information acquisition module, which is used to obtain the parameter information of the wireless charging system transceiver and exchange the parameter information of the transceiver; A target power calculation module, which is used to determine the target output power based on the parameter information of the transmitting and receiving ends; A parameter setting module is used to identify the mutual inductance of the coupled coil, calculate the mutual inductance offset ratio γ and the conduction phase angle α of the switch-controlled capacitor switch, and set the phase-controlled capacitor switch duty cycle of the switch-controlled capacitor; A constant power calculation module, which is used to output the constant power of the wireless charging system according to the results calculated and set by the parameter setting module; The logic judgment module is used to judge whether the output power meets the requirements. If so, the parameter setting module and the constant power calculation module are re-executed after a set time, and the judgment on whether the output power meets the requirements is continued until the current power output control is completed. If not, the parameter setting module and the constant power calculation module are directly re-executed until the output power meets the requirements.

8. A computer terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When executing the computer program, the processor can be used to perform the method according to any one of claims 1 to 6, or run the system according to claim 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it can be used to perform the method according to any one of claims 1 to 6, or to run the system according to claim 7.

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