Wireless energy transmission system soft start method based on input impedance adjustment

Abstract

The application provides a wireless energy transmission system soft start method based on input impedance adjustment, which comprises the following steps: determining a voltage / current gain-frequency characteristic curve of a wireless energy transmission system based on hardware information of the wireless energy transmission system; determining a target resonant frequency and an initial resonant frequency based on the voltage / current gain-frequency characteristic curve; determining an intermediate frequency, a first time interval and a second time interval based on the hardware information of the wireless energy transmission system, wherein the intermediate frequency is between the target resonant frequency and the initial resonant frequency; setting a switching frequency of the wireless energy transmission system to the initial resonant frequency, adjusting the switching frequency to the intermediate frequency within the first time interval, and adjusting the switching frequency from the intermediate frequency to the target resonant frequency and maintaining the target resonant frequency within the second time interval. The method effectively suppresses voltage and current stress in the system starting process, realizes smooth and reliable starting, and does not need to increase additional hardware circuit.

Description

Technical Field

[0001] This application relates to the field of wireless power transfer technology, and in particular to a soft-start method for a wireless power transfer system based on input impedance adjustment. Background Technology

[0002] Wireless power transfer (WPT) technology is widely used in electric vehicles, consumer electronics, and industrial robots due to its advantages such as safety, convenience, and contactlessness. Wireless power transfer systems based on magnetically coupled resonance (MCR) often incorporate compensation topologies to improve transmission power and efficiency. LCC compensation networks, with their superior characteristics such as primary-side constant current and ease of soft-switching, have become a mainstream compensation scheme.

[0003] However, in practical applications, LCC compensation networks have a significant startup problem: the ideal operating point of the system is at the resonant frequency, where the system impedance is minimum. If the system operates at this resonant point at the moment of power-on, the initial voltage of the DC bus capacitor and the compensation network capacitor will be zero, triggering a huge instantaneous inrush current and voltage stress on the components. Such surge currents and voltage spikes can easily cause overcurrent damage to the inverter bridge's switching devices (MOSFETs, IGBTs) or cause the compensation capacitors to break down due to overvoltage, seriously threatening the system's startup reliability.

[0004] In existing technologies, this problem is often addressed by using pre-charging circuits or increasing component margins. However, pre-charging circuits increase system complexity and cost; while increasing component margins leads to an increase in system size and cost. Summary of the Invention

[0005] In view of this, embodiments of this application provide a soft-start method for a wireless power transfer system based on input impedance adjustment to address the technical deficiencies in the prior art. Embodiments of this application also provide a computing device and a computer-readable storage medium.

[0006] According to a first aspect of the embodiments of this application, a soft-start method for a wireless power transfer system based on input impedance adjustment is provided, comprising: Based on the hardware information of the wireless power transmission system, determine the voltage / current gain-frequency characteristic curve of the wireless power transmission system; Based on the voltage / current gain-frequency characteristic curve, the target resonant frequency and the initial resonant frequency are determined. Based on the hardware information of the wireless power system, an intermediate frequency, a first time interval, and a second time interval are determined, wherein the intermediate frequency is between the target resonant frequency and the initial resonant frequency; The switching frequency of the wireless power transmission system is set to the initial resonant frequency. During the first time interval, the switching frequency is adjusted to an intermediate frequency. During the second time interval, the switching frequency is adjusted from the intermediate frequency to the target resonant frequency and maintained.

[0007] Optionally, determining the target resonant frequency and the initial resonant frequency based on the voltage / current gain-frequency characteristic curve includes: Based on the voltage / current gain-frequency characteristic curve, the target resonant frequency and the numerical range in which the system gain remains monotonically changing are determined. The numerical range is compared with a preset numerical range threshold. If the numerical range is greater than or equal to the numerical range threshold, the initial resonant frequency is determined based on the target resonant frequency and the numerical range threshold. If the numerical range is less than the numerical range threshold, the initial resonant frequency is determined based on the target resonant frequency and the numerical range.

[0008] Optionally, determining the intermediate frequency, the first time interval, and the second time interval based on the hardware information of the wireless power system includes: The stress data of the first device and the stress data of the second device are determined by the component parameters contained in the hardware information. Based on the stress data of the first device and the initial resonant frequency, the intermediate frequency and the first time interval are determined; The second time interval is determined based on the stress data of the second device, the intermediate frequency, and the target resonant frequency.

[0009] Optionally, the sum of the first time interval and the second time interval is less than or equal to a preset time interval threshold.

[0010] Optionally, the soft-start process of the wireless power transmission system is continuously monitored, and operational data is collected. The first time interval and the second time interval are dynamically adjusted based on the operational data.

[0011] Optionally, the step of defining the first device stress data and the second device stress data using the component parameters included in the hardware information includes: Based on the component parameters, determine the stress data of the calibration device; Based on a preset division ratio, the stress data of the calibration device is divided to obtain the stress data of the first device and the stress data of the second device.

[0012] Optionally, setting the switching frequency of the wireless power transfer system to the initial resonant frequency includes: The switching frequency of the wireless power transmission system is set to the initial resonant frequency, and a target shift angle is applied.

[0013] Optionally, the target shift angle ranges from 0° to 180°, and when the switching frequency is adjusted from the initial resonant frequency to the intermediate frequency, the target shift angle increases or decreases linearly with the frequency.

[0014] Optionally, the wireless power transmission system includes a DC power supply, a high-frequency inverter circuit, a first resonant compensation circuit and a transmitting coil connected in series on the primary side, and a receiving coil, a second resonant compensation circuit, a rectifier filter circuit and an output load connected in series on the secondary side.

[0015] Optionally, the operating time of the wireless power transmission system is monitored, and when the operating time is greater than or equal to a preset operating time threshold, parameter correction is performed during the next soft-start process.

[0016] According to a second aspect of the embodiments of this application, a computing device is provided, comprising: Memory and processor; The memory is used to store computer-executable instructions, and when the processor executes the computer-executable instructions, it implements the steps of the soft-start method for the wireless power transmission system based on input impedance adjustment.

[0017] According to a third aspect of the embodiments of this application, a computer-readable storage medium is provided that stores computer-executable instructions, which, when executed by a processor, implement the steps of the soft-start method for the wireless power transfer system based on input impedance adjustment.

[0018] According to a fourth aspect of the present application, a chip is provided that stores a computer program, which, when executed by the chip, implements the steps of the soft-start method for the wireless power transfer system based on input impedance adjustment.

[0019] The soft-start method for a wireless power transmission system based on input impedance adjustment provided in this application determines the voltage / current gain-frequency characteristic curve of the wireless power transmission system based on its hardware information; determines the target resonant frequency and the initial resonant frequency based on the voltage / current gain-frequency characteristic curve; determines an intermediate frequency, a first time interval, and a second time interval based on the hardware information of the wireless power transmission system, wherein the intermediate frequency is between the target resonant frequency and the initial resonant frequency; sets the switching frequency of the wireless power transmission system to the initial resonant frequency; adjusts the switching frequency to the intermediate frequency during the first time interval; and adjusts the switching frequency from the intermediate frequency to the target resonant frequency and maintains it during the second time interval. This effectively suppresses voltage and current stress during system startup, achieving smooth and reliable startup without the need for additional hardware circuitry. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a soft-start method for a wireless power transfer system based on input impedance adjustment, provided in an embodiment of this application. Figure 2 This is a schematic flowchart of a soft-start method for a wireless power transfer system based on input impedance adjustment, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the converter topology of a soft-start method for a wireless power transfer system based on input impedance adjustment, provided in an embodiment of this application. Figure 4 This is a structural block diagram of a soft-start method for a wireless power transfer system based on input impedance adjustment, provided in an embodiment of this application. Figure 5 This is a structural block diagram of a computing device provided in one embodiment of this application.

[0022] Figure 3 In the middle, V in - DC power supply, Q1 - primary side first switching transistor, Q2 - primary side second switching transistor, Q3 - primary side third switching transistor, Q4 - primary side fourth switching transistor, L1 - primary side series compensation inductor, C1 - primary side parallel compensation capacitor, C p - Primary winding compensation capacitor, M- Mutual inductance between primary and secondary windings, C s- Secondary coil compensation capacitor, D1 - Secondary first diode, D2 - Secondary second diode, D3 - Secondary third diode, D4 ​​- Secondary fourth diode, C2 - Secondary parallel compensation capacitor, Q5 - Secondary fifth switching transistor, D5 - Secondary fifth diode, L f - Secondary-side series compensation inductor, C o - Output filter capacitor, R L - Output load, V o - Output voltage. Detailed Implementation

[0023] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0024] The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms “a,” “the,” and “the” used in one or more embodiments of this application and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0025] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this application, and similarly, second may also be referred to as first.

[0026] This application provides a soft-start method for a wireless power transfer system based on input impedance adjustment. This application also relates to a computing device and a computer-readable storage medium, which will be described in detail in the following embodiments.

[0027] Figure 1 The flowchart illustrates a soft-start method for a wireless power transfer system based on input impedance adjustment according to an embodiment of this application, specifically including the following steps: Step S102: Based on the hardware information of the wireless power transmission system, determine the voltage / current gain-frequency characteristic curve of the wireless power transmission system; Step S104: Based on the voltage / current gain-frequency characteristic curve, determine the target resonant frequency and the initial resonant frequency; Step S106: Based on the hardware information of the wireless power system, determine the intermediate frequency, the first time interval, and the second time interval, wherein the intermediate frequency is between the target resonant frequency and the initial resonant frequency; Step S108: Set the switching frequency of the wireless power transmission system to the initial resonant frequency, adjust the switching frequency to the intermediate frequency during the first time interval, and adjust the switching frequency from the intermediate frequency to the target resonant frequency and maintain it during the second time interval.

[0028] The hardware information of the wireless power transmission system refers to the parameters and topology information of various components in the system, including DC power supply specifications, high-frequency inverter circuit switching transistor parameters, resonant compensation circuit components such as capacitors, inductors, coil parameters, rectifier filter circuit parameters, and load characteristics. The voltage / current gain-frequency characteristic curve, with the switching frequency as the independent variable and the system voltage gain or current gain as the dependent variable, reflects the change in system gain at different switching frequencies and is the core basis for determining the resonant frequency. The target resonant frequency represents the resonant frequency at which the system achieves rated gain and optimal operating efficiency, corresponding to the peak point of the voltage / current gain-frequency characteristic curve or the frequency corresponding to the design target value. The initial resonant frequency represents the initial switching frequency set at the start of soft start, deviating from the target resonant frequency, used to avoid the impact caused by directly switching to the target frequency during the initial startup. The intermediate frequency is the transition frequency between the initial resonant frequency and the target resonant frequency, used to achieve segmented and smooth frequency adjustment and buffer stress changes between the two frequency ranges. The first time interval corresponds to the adjustment time from the initial frequency to the intermediate frequency, and the second time interval corresponds to the adjustment time from the intermediate frequency to the target frequency. Both the first and second time intervals are set based on the stress tolerance capability of the components.

[0029] Therefore, by first constructing a gain-frequency characteristic curve to clarify the system characteristics, and then setting an intermediate frequency to achieve segmented frequency adjustment, the impact caused by frequency abrupt changes is avoided. The adjustment time is allocated in stages to make the switching frequency smoothly transition to the target resonant frequency, effectively reducing the starting stress of components and improving the stability of the soft start process and the reliability of the system.

[0030] Furthermore, in step S104, the process of determining the target resonant frequency and the initial resonant frequency based on the voltage / current gain-frequency characteristic curve is specifically implemented as follows in this embodiment: Based on the voltage / current gain-frequency characteristic curve, the target resonant frequency and the numerical range in which the system gain remains monotonically changing are determined; the numerical range is compared with a preset numerical range threshold; when the numerical range is greater than or equal to the numerical range threshold, the initial resonant frequency is determined based on the target resonant frequency and the numerical range threshold; when the numerical range is less than the numerical range threshold, the initial resonant frequency is determined based on the target resonant frequency and the numerical range.

[0031] The numerical range within which the system gain maintains a monotonically changing value refers to the frequency range on the voltage / current gain-frequency characteristic curve where the gain increases or decreases monotonically with frequency. Within this range, the system gain characteristics are stable and there is no risk of abrupt changes. The numerical range threshold is a preset critical value for the frequency range based on the system component tolerance and startup efficiency requirements. It is used to determine whether the monotonically changing range meets the initial frequency setting requirements.

[0032] Based on this, the target resonant frequency is determined to be A in the voltage / current gain-frequency characteristic curve, and the numerical range in which the system gain remains monotonically changing is [a, b], with a threshold of B. When |ab|≥B, the initial resonant frequency is A±B, and conversely, when |ab|<B, the initial resonant frequency is A±|ab|.

[0033] For example, such as Figure 2 A flowchart of a soft-start method for a wireless power transfer system based on input impedance adjustment is provided. When the steady-state resonant frequency of the system, i.e. the target resonant frequency, is 200kHz, the initial resonant frequency can be preferably set to 230kHz based on the above principle.

[0034] Therefore, to avoid blindly setting the initial frequency, which could exceed the monotonic variation range of the system gain and cause a sudden gain change during startup, leading to operational instability and inability to adapt to systems with different gain characteristics, the initial switching frequency of the primary-side inverter circuit is not arbitrarily set when the system is powered on. Instead, it is determined by analyzing the voltage / current gain-frequency characteristic curve of the system. The preferred principle is that the system gain, such as voltage gain or current gain, must maintain a strictly monotonic variation characteristic throughout the entire scanning range from the initial frequency to the target resonant frequency. It should be noted that the monotonic variation characteristic includes monotonically increasing or decreasing, and the specific choice depends on the actual application scenario. This embodiment does not impose any limitations on this.

[0035] Furthermore, it should be noted that the selected operating frequency range is strictly limited to the inductive operating region of the inverter to fundamentally avoid increased switching losses and bridge arm shoot-through risks caused by capacitive turn-on, ensuring the safety of power devices. The initial resonant frequency is dynamically determined based on the monotonic interval of the gain-frequency characteristic curve and a preset threshold, ensuring that the initial frequency falls within the stable gain range and avoiding sudden gain changes. The initial frequency calculation method is flexibly adjusted according to the size of the monotonic interval, improving the method's adaptability to wireless power transfer systems with different topologies and parameters, further guaranteeing startup stability.

[0036] Furthermore, in step S106, the process of determining the intermediate frequency, the first time interval, and the second time interval based on the hardware information of the wireless power system is specifically implemented as follows in this embodiment: Using the component parameters contained in the hardware information, first component stress data and second component stress data are defined; based on the first component stress data and the initial resonant frequency, the intermediate frequency and the first time interval are determined; based on the second component stress data, the intermediate frequency and the target resonant frequency, the second time interval is determined.

[0037] Furthermore, in the above steps, the sum of the first time interval and the second time interval is less than or equal to a preset time interval threshold.

[0038] Furthermore, in the above steps, the soft-start process of the wireless power transmission system is continuously monitored, and operational data is collected. Based on the operational data, the first time interval and the second time interval are dynamically adjusted.

[0039] Furthermore, in the above steps, the process of defining the stress data of the first device and the stress data of the second device using the component parameters contained in the hardware information is specifically implemented as follows in this embodiment: Based on the component parameters, the stress data of the calibration device is determined; based on a preset division ratio, the stress data of the calibration device is divided to obtain the stress data of the first device and the stress data of the second device.

[0040] The component parameters include core parameters such as the withstand voltage, rated current, and response speed of the switching transistor; the capacitance, inductance, and rated power of the resonant capacitor / inductor; and the internal resistance and mutual inductance coefficient of the coil. The first and second component stress data characterize the physical quantities such as voltage, current, power load, and temperature rise that the component withstands during operation. These first and second stress data are two sets of stress thresholds based on segmented requirements during the startup phase, corresponding to the two stages of frequency adjustment. The time interval threshold is the upper limit of the total soft-start time set based on system startup response requirements and load power supply timeliness requirements, ensuring that the soft-start process does not affect the normal power supply sequence of the system. The operating data characterizes core operating parameters such as primary-side current, secondary-side voltage, component temperature rise, actual switching frequency adjustment rate, and system gain collected in real time during the soft-start process. The calibrated component stress data is the maximum stress reference value that the component can withstand throughout the soft-start process, determined based on the component's rated parameters, manufacturer's technical specifications, and system design goals, or through laboratory measurements, and serves as the basis for segmenting the stress data.

[0041] Based on this, stress data is defined according to the parameters of hardware components, so that the setting of intermediate frequency and adjustment time is close to the actual tolerance capacity of the components, avoiding stress overload; by corresponding to different stress data in stages, the frequency adjustment and device protection are precisely matched, taking into account both start-up stability and component lifespan; by limiting the total duration of the two time intervals to not exceed a preset threshold, the soft-start stability and start-up efficiency are balanced, avoiding excessive total time consumption due to segmented adjustment; at the same time, it forces the reasonable allocation of the first and second time intervals, ensuring that the soft-start process meets the device protection requirements while adapting to the load power supply timing requirements.

[0042] The stress distribution ratio, set based on the characteristics of the two-stage frequency adjustment in soft-start, adapts to the buffer stage from the initial resonant frequency to the intermediate frequency, and the precise adjustment stage from the intermediate frequency to the target resonant frequency, meeting the device load requirements at different stages. Using calibrated stress data as a benchmark, combined with a preset ratio to divide the stress data into segments, ensures the scientific and standardized nature of the stress threshold setting. A unified stress data acquisition logic makes the method reproducible, adaptable to wireless power transmission systems with different component specifications, and improves the versatility of the technical solution. Furthermore, based on real-time operational data feedback, the first / second time interval of the ongoing soft-start process is corrected in real time, or parameter optimization is provided for the next soft-start. Through real-time monitoring and dynamic adjustment, the time interval is adapted to the real-time operating status during the soft-start process, improving the robustness of the method. Timely correction of adjustment duration for sudden operational data anomalies prevents fault escalation and further ensures the stability and reliability of the soft-start process.

[0043] Continuing with the previous example, such as Figure 2The flowchart illustrates a soft-start method for a wireless power transfer system based on input impedance adjustment. The intermediate frequency is defined as 220kHz, the first time interval as 100ns, and the second time interval as 700ns. Therefore, during steady-state operation, the switching frequency is fixed at the target resonant frequency. f _steady =200kHz. During startup, after the system is powered on by DC, the auxiliary power supply starts working, the controller initializes, and upon receiving the startup command, the controller sets the switching frequency of the PWM signal to the initial frequency. f _start =230kHz. This frequency value was determined through offline analysis or online calculation, ensuring that the frequency was first decreased from 230kHz to 220kHz, and after the system operated at 220kHz for 700ns, the frequency was gradually adjusted from 220kHz to 200kHz. During the entire frequency adjustment period, the system gain monotonically decreased and always operated in the safe inductive region, creating conditions for the switching transistor to achieve ZVS. At this time, because the system operating frequency is higher than the resonant point, the system as a whole is inductive and has a large impedance.

[0044] In other words, the controller starts an internal timer, which is set to activate within a predetermined time interval threshold. T soft Within 1ms, the frequency of the PWM signal is uniformly reduced from 230kHz to 200kHz using a linear ramp function. This 1ms duration was determined experimentally by observing the dynamic response of the voltage and current waveforms during system startup. Within this time, the DC bus current and compensation capacitor voltage rise smoothly from zero, avoiding any form of shock, and reach steady-state operating values ​​precisely at the end of the cycle. After the frequency change is complete, the controller locks the frequency at 200kHz, and the system enters steady-state operation mode. During this process, due to the high impedance at the initial frequency, the startup current of the inverter bridge is effectively limited to a low level. As the frequency gradually approaches the resonant point, the system impedance gradually decreases, and the transmitted power and current smoothly increase to their rated values, thus completely avoiding startup shock.

[0045] Furthermore, in step S108, within the set soft-start time, the control unit drives the switching frequency to automatically and continuously adjust from the initial resonant frequency to the target resonant frequency. The frequency change trajectory can be planned according to system requirements, and various methods such as linear slope and nonlinear function can be used to optimize dynamic performance. The setting of the first time interval, the second time interval, the initial resonant frequency, the target resonant frequency, and the intermediate frequency ensures that at the end of the soft-start process, the voltage and current stress on each key component in the system, such as the compensation inductor, capacitor, and switching transistor, can achieve a smooth transition and ultimately converge to the steady-state value without overshoot.

[0046] Furthermore, in step S108, the process of setting the switching frequency of the wireless power transmission system to the initial resonant frequency is specifically implemented as follows in this embodiment: The switching frequency of the wireless power transmission system is set to the initial resonant frequency, and a target shift angle is applied.

[0047] Furthermore, in the above steps, the target shift angle ranges from 0° to 180°, and when the switching frequency is adjusted from the initial resonant frequency to the intermediate frequency, the target shift angle increases or decreases linearly with the frequency.

[0048] The target shift angle is a control parameter used to adjust the equivalent amplitude of the output voltage of the high-frequency inverter circuit. By changing the phase difference of the switching transistor's turn-on timing, the output power can be finely adjusted. During the linear increase / decrease process, the shift angle changes linearly with the switching frequency. That is, for every unit change in frequency, the shift angle increases or decreases synchronously at a fixed rate to ensure a smooth transition of the control quantity.

[0049] Based on this, while performing frequency scanning from the initial resonant frequency to the target resonant frequency, a phase-shift soft-start operation is simultaneously introduced. By applying a small phase shift angle at the initial stage of startup, the initial power surge is limited, and this, in conjunction with the frequency scanning, achieves precise suppression of surge current and voltage during system startup, resulting in a smoother power build-up process. Figure 3 A converter topology diagram of a soft-start method for a wireless power transfer system based on input impedance regulation is provided. It includes a primary-side inverter bridge composed of a primary-side first switch Q1, a primary-side second switch Q2, a primary-side third switch Q3, and a primary-side fourth switch Q4, and a primary-side series compensation inductor L1, a primary-side parallel compensation capacitor C1, and a primary-side coil compensation capacitor C. p Through the primary-side LCC compensation network, the secondary-side coil compensation capacitor C s Parallel compensation capacitor C2 on the secondary side and series compensation inductor L on the secondary side f The secondary-side LCC compensation network, the rectifier circuit composed of secondary-side first diode D1, secondary-side second diode D2, secondary-side third diode D3, and secondary-side fourth diode D4, and the DC power supply V in The fifth secondary switch Q5, the fifth secondary diode D5, and the output filter capacitor C. o Output load R L It consists of coils with a mutual inductance of M between the primary and secondary windings, and the output voltage is V. oThe controller's embedded soft-start program generates a PWM drive signal with a gradually changing frequency according to a predetermined pattern after power-on, directly driving the inverter bridge switching transistors. By applying a target shift angle while setting the initial resonant frequency, and through coordinated control of the shift angle and frequency, fine adjustment of the output power is achieved. This avoids power surges caused by relying solely on frequency adjustment, further buffering the startup impact, and accurately matching the initial power supply requirements of the load, improving the power controllability of the soft-start process. Furthermore, a reasonable shift angle range of 0°-180° is limited to prevent abnormal inverter circuit operation. The linear coordinated change of the shift angle and frequency ensures smooth and synchronous power regulation and frequency adjustment, maximizing the buffering of startup impact and improving the control accuracy and stability of the soft-start process.

[0050] Furthermore, the wireless power transmission system includes a DC power supply, a high-frequency inverter circuit, a first resonant compensation circuit and a transmitting coil connected in series on the primary side, and a receiving coil, a second resonant compensation circuit, a rectifier and filter circuit and an output load connected in series on the secondary side.

[0051] Among them, such as Figure 4 The provided structural block diagram of a soft-start method for a wireless power transmission system based on input impedance adjustment shows that the primary side represents the side of the wireless power transmission system responsible for power conversion and transmission, including a DC power supply that provides initial DC power, a high-frequency inverter circuit that converts DC power into high-frequency AC power, a first resonant compensation circuit for optimizing high-frequency power transmission characteristics and reducing reactive power loss, and a transmitting coil that transmits power in the form of an electromagnetic field. The secondary side represents the side of the wireless power transmission system responsible for power reception and conversion, including a receiving coil that receives electromagnetic field energy and converts it into high-frequency AC power, a second resonant compensation circuit that matches the primary side compensation circuit to improve transmission efficiency, a rectifier and filter circuit that converts high-frequency AC power into stable DC power, and the output load of the device or module that receives and consumes power.

[0052] Furthermore, the operating time of the wireless power transmission system is monitored, and when the operating time is greater than or equal to a preset operating time threshold, parameter correction is performed during the next soft start process.

[0053] The runtime threshold, defined as a critical time value based on component aging patterns and system stability requirements, is used to determine whether parameter calibration is necessary. It typically corresponds to the performance degradation period after cumulative component operation. The parameter calibration process involves re-acquiring hardware information and calibrating soft-start parameters such as resonant frequency and time interval to address gain-frequency characteristic curve shifts caused by system aging and component parameter drift. This ensures the parameters match the current system state. Therefore, by monitoring the system's cumulative runtime and periodically calibrating parameters, the impact of component aging and parameter drift is offset, ensuring the soft-start parameters always match the current system state. This extends the long-term applicability of the soft-start method and guarantees the system's startup stability and reliability throughout its entire lifecycle.

[0054] In summary, the soft-start method for a wireless power transfer system based on input impedance adjustment of the present invention fundamentally increases the system impedance at the moment of startup by actively controlling the frequency to deviate from the resonant point, significantly reducing inrush current and voltage stress; it is implemented through software algorithms, eliminating the need for additional hardware such as pre-charging resistors and relays, saving cost and space, and improving system reliability; the continuous and gradual change of frequency ensures a smooth and shock-free transition of the system from startup to steady-state operation; and it is easy to implement on a digital controller, making it widely applicable to various wireless power transfer systems using LCC and its derived compensation topologies.

[0055] Figure 5 A structural block diagram of a computing device 500 according to an embodiment of this application is shown. The components of the computing device 500 include, but are not limited to, a memory 510 and a processor 520. The processor 520 is connected to the memory 510 via a bus 530, and a database 550 is used to store data.

[0056] The computing device 500 also includes an access device 540, which enables the computing device 500 to communicate via one or more networks 560. Examples of these networks include a Public Switched Telephone Network (PSTN), a Local Area Network (LAN), a Wide Area Network (WAN), a Personal Area Network (PAN), or a combination of communication networks such as the Internet. The access device 540 may include one or more of any type of wired or wireless network interface (e.g., a Network Interface Card (NIC)), such as an IEEE 802.11 Wireless Local Area Network (WLAN) interface, a Wi-MAX interface, an Ethernet interface, a Universal Serial Bus (USB) interface, a cellular network interface, a Bluetooth interface, a Near Field Communication (NFC) interface, and so on.

[0057] In one embodiment of this application, the aforementioned components of the computing device 500 and Figure 5 Other components, not shown, can also be connected to each other, for example, via a bus. It should be understood that... Figure 5 The block diagram of the computing device shown is for illustrative purposes only and is not intended to limit the scope of this application. Those skilled in the art can add or replace other components as needed.

[0058] The computing device 500 can be any type of stationary or mobile computing device, including mobile computers or mobile computing devices (e.g., tablet computers, personal digital assistants, laptop computers, notebook computers, netbooks, etc.), mobile phones (e.g., smartphones), wearable computing devices (e.g., smartwatches, smart glasses, etc.) or other types of mobile devices, or stationary computing devices such as desktop computers or PCs. The computing device 500 can also be a mobile or stationary server.

[0059] The processor 520 is used to execute computer-executable instructions for each step of the soft-start method for a wireless power transfer system based on input impedance adjustment.

[0060] The above is a schematic representation of a computing device according to this embodiment. It should be noted that the technical solution of this computing device and the aforementioned soft-start method for a wireless power transfer system based on input impedance adjustment belong to the same concept. Details not described in detail in the technical solution of the computing device can be found in the description of the aforementioned soft-start method for a wireless power transfer system based on input impedance adjustment.

[0061] An embodiment of this application also provides a computer-readable storage medium storing computer instructions that, when executed by a processor, are used to implement the steps of the soft-start method for a wireless power transfer system based on input impedance adjustment.

[0062] The above is an illustrative scheme of a computer-readable storage medium according to this embodiment. It should be noted that the technical solution of this storage medium belongs to the same concept as the technical solution of the above-described soft-start method for a wireless power transfer system based on input impedance adjustment. For details not described in detail in the technical solution of the storage medium, please refer to the description of the above-described technical solution of the soft-start method for a wireless power transfer system based on input impedance adjustment.

[0063] An embodiment of this application also provides a chip that stores a computer program, which, when executed by the chip, implements the steps of the soft-start method for a wireless power transfer system based on input impedance adjustment.

[0064] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0065] The computer instructions include computer program code, which may be in the form of source code, object code, executable file, or certain intermediate forms. The computer-readable medium may include any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium may be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media may not include electrical carrier signals and telecommunication signals.

[0066] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0068] The preferred embodiments disclosed above are merely illustrative of this application. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this application. These embodiments are selected and specifically described in this application to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application. This application is limited only by the claims and their full scope and equivalents.

Claims

1. A soft-start method for a wireless power transfer system based on input impedance adjustment, characterized in that, include: Based on the hardware information of the wireless power transmission system, determine the voltage / current gain-frequency characteristic curve of the wireless power transmission system; Based on the voltage / current gain-frequency characteristic curve, the target resonant frequency and the initial resonant frequency are determined. Based on the hardware information of the wireless power system, an intermediate frequency, a first time interval, and a second time interval are determined, wherein the intermediate frequency is between the target resonant frequency and the initial resonant frequency; The switching frequency of the wireless power transmission system is set to the initial resonant frequency. During the first time interval, the switching frequency is adjusted to an intermediate frequency. During the second time interval, the switching frequency is adjusted from the intermediate frequency to the target resonant frequency and maintained.

2. The method according to claim 1, characterized in that, The determination of the target resonant frequency and the initial resonant frequency based on the voltage / current gain-frequency characteristic curve includes: Based on the voltage / current gain-frequency characteristic curve, the target resonant frequency and the numerical range in which the system gain remains monotonically changing are determined. The numerical range is compared with a preset numerical range threshold. If the numerical range is greater than or equal to the numerical range threshold, the initial resonant frequency is determined based on the target resonant frequency and the numerical range threshold. If the numerical range is less than the numerical range threshold, the initial resonant frequency is determined based on the target resonant frequency and the numerical range.

3. The method according to claim 1, characterized in that, The determination of the intermediate frequency, the first time interval, and the second time interval based on the hardware information of the wireless power system includes: The stress data of the first device and the stress data of the second device are determined by the component parameters contained in the hardware information. Based on the stress data of the first device and the initial resonant frequency, the intermediate frequency and the first time interval are determined; The second time interval is determined based on the stress data of the second device, the intermediate frequency, and the target resonant frequency.

4. The method according to claim 3, characterized in that, The sum of the first time interval and the second time interval is less than or equal to a preset time interval threshold.

5. The method according to claim 3, characterized in that, The soft-start process of the wireless power transmission system is continuously monitored, and operational data is collected. Based on the operational data, the first time interval and the second time interval are dynamically adjusted.

6. The method according to claim 3, characterized in that, The step of defining the first device stress data and the second device stress data using the component parameters contained in the hardware information includes: Based on the component parameters, determine the stress data of the calibration device; Based on a preset division ratio, the stress data of the calibration device is divided to obtain the stress data of the first device and the stress data of the second device.

7. The method according to claim 1, characterized in that, Setting the switching frequency of the wireless power transmission system to the initial resonant frequency includes: The switching frequency of the wireless power transmission system is set to the initial resonant frequency, and a target shift angle is applied.

8. The method according to claim 7, characterized in that, The target shift angle ranges from 0° to 180°, and when the switching frequency is adjusted from the initial resonant frequency to the intermediate frequency, the target shift angle increases or decreases linearly with the frequency.

9. The method according to claim 1, characterized in that, The wireless power transmission system includes a DC power supply, a high-frequency inverter circuit, a first resonant compensation circuit and a transmitting coil connected in series on the primary side, and a receiving coil, a second resonant compensation circuit, a rectifier and filter circuit and an output load connected in series on the secondary side.

10. The method according to claim 1, characterized in that, Monitor the operating time of the wireless power transmission system. If the operating time is greater than or equal to a preset operating time threshold, perform parameter correction during the next soft start process.

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