A pair of two wireless power transmission system based on adaptive load identification and topology switching method

Abstract

This invention discloses a one-to-two wireless power transfer system and topology switching method based on adaptive load identification, belonging to the field of wireless power transfer technology. The system includes one transmitter and two independent receivers. The transmitter employs fixed series compensation; each receiver includes a receiving coil, a rectifier filter circuit, and a switchable compensation network. The method involves each receiver's microcontroller running an adaptive load identification algorithm based on sliding window statistical characteristics to dynamically calculate light and heavy load thresholds in real time. Combined with hysteresis constraints and anti-jitter confirmation mechanisms, the system identifies the load state based on voltage and current sampling. Under the condition of meeting the minimum switching interval, the system drives the execution circuit to automatically switch the switchable compensation network between series and parallel topologies. This invention achieves distributed autonomous control without communication with the transmitter, achieving an average transmission efficiency of 8284% over a wide load range of 1050Ω, significantly superior to a fixed topology.

Description

Technical Field

[0001] This invention belongs to the field of wireless power transmission technology, specifically relating to a one-to-two wireless power transmission system and topology switching method based on adaptive load identification. Background Technology

[0002] Wireless power transfer technology, with its convenience and security, shows great promise in consumer electronics, industrial equipment, and electric vehicles. However, existing one-to-two wireless power transfer systems face severe challenges in efficiency and stability when dealing with dynamic load changes. The core issues are mainly reflected in the inherent contradictions of fixed compensation topologies, the poor adaptability of load identification mechanisms based on fixed thresholds, and the scalability and reliability bottlenecks of centralized control with multiple receivers.

[0003] Existing systems typically employ fixed compensation topologies, such as series-series (SS) or series-parallel (SP). However, SS topologies are prone to frequency splitting under light loads, leading to a sharp drop in efficiency, while SP topologies suffer from inefficiency due to excessive circulating current losses under heavy loads. When the system load varies over a wide range, a single fixed topology cannot maintain high efficiency throughout, creating a technical contradiction of "not being able to handle both heavy and light loads simultaneously." To achieve topology switching, some improved solutions employ load detection technology, but these often rely on preset fixed power or current thresholds. In actual operation, system parameters drift due to temperature drift, aging, or displacement, causing the fixed thresholds to gradually deviate from the optimal operating point, leading to misjudgments and frequent switching. Under dynamic operating conditions with rapidly changing loads, static thresholds cannot track continuous changes in system state, often resulting in inappropriate switching timing and ultimately impairing system performance. For one-to-two systems, existing solutions often employ a centralized control architecture, requiring the establishment of communication links between the transmitter and each receiver to coordinate actions. This not only increases system complexity and cost but also introduces communication delays, interruption risks, and electromagnetic compatibility issues. As the number of receivers increases, communication and computing overhead grows dramatically, resulting in poor system scalability. Furthermore, when the load of each receiver changes asynchronously and independently, the centralized controller struggles to make fast and optimal global decisions, easily leading to system oscillations between multiple local optima and insufficient stability.

[0004] Therefore, there is an urgent need to develop a distributed wireless power transmission system that can automatically identify load status, autonomously switch topologies, and make independent decisions for each receiver in a dynamic environment with multiple load changes, so as to meet the stringent requirements of modern industrial applications for the reliability, efficiency and intelligence of power transmission systems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a one-to-two wireless power transmission system and topology switching method based on adaptive load identification.

[0006] This invention discloses a one-to-two wireless power transmission system based on adaptive load identification, employing a distributed autonomous architecture. The transmitting end uses a fixed series compensation method and includes a high-frequency inverter circuit, a transmitting coil, and its corresponding control and protection circuits. Each receiving end is equipped with a complete energy receiving and processing unit, including a receiving coil, a rectifier and filter circuit, a switchable compensation network, a voltage and current sampling circuit, a microcontroller, and a switching execution circuit. By embedding the microcontroller and running an adaptive load identification algorithm, the system determines the load status in real time, generates a topology switching control signal, and manages the operating status of the receiving end, autonomously switching between series compensation and parallel compensation topologies, thereby achieving high-efficiency transmission over a wide load range.

[0007] A one-to-two wireless power transfer method based on adaptive load identification specifically includes the following steps: S1. System power-on initialization and parameter preset; The preset parameters include sliding window length, sensitivity coefficient, hysteresis coefficient, anti-shake confirmation count, and minimum switching time interval; After the system of this invention is powered on, each receiver microcontroller executes an initialization program: setting the default topology of the switchable compensation network to an SP topology of transmitter series-receiver parallel connection; and clearing the sliding window used to store historical power data. S2. Synchronous acquisition and calculation of voltage and current at the receiving end: Based on each preset fixed sampling interval, the voltage and current at both ends are synchronously acquired through the voltage sampling circuit and current sampling circuit at the receiving end, and the instantaneous output power and power change rate are calculated. The voltage sampling circuit is specifically implemented through a resistor voltage divider circuit with a voltage division ratio of 10:1. Upon power-up, the system of this invention first enters the initialization phase, setting the default operating state to an SP topology suitable for light load conditions, and simultaneously clearing all historical data within the sliding window. The sliding window size is a preset value. During each sampling period, the system synchronously acquires the output voltage. and output current The instantaneous power and the rate of change of power are obtained through calculation. The expression for calculating the instantaneous power is as follows:

[0008] in, For output current, This refers to the output voltage. The expression for calculating the rate of change of power is:

[0009] in, For instantaneous power, sampling interval .

[0010] S3. Sliding Window Update and Adaptive Threshold Calculation: Based on a sliding window with preset power sampling values, the instantaneous output power and power change rate are input into the sliding window for updating, and the mean, standard deviation, and 25th percentile are calculated. and 75th percentile Statistical characteristics were obtained; The adaptive threshold calculation employs power statistical feature extraction. The statistical characteristics include: mean, standard deviation, and 25th percentile. and 75th percentile ; The adaptive threshold calculation of this invention adopts an analysis method based on power statistical feature extraction. The system maintains a sliding window containing the most recent 30 power sample values ​​in real time, and calculates the mean of the power data within the window. and standard deviation This is used to measure the dispersion of power data; it also calculates the 25th percentile. and 75th percentile , and Statistics can effectively characterize the boundary features of power distribution.

[0011] The expression for calculating the mean is:

[0012] in, The preset power sampling value, for index, For the first The power of each power sample value; The expression for calculating standard deviation is:

[0013] in, This is the mean.

[0014] S4. Dynamic load judgment threshold calculation and adaptive correction: Based on statistical characteristics, the dynamic light load threshold and dynamic heavy load threshold are calculated, and the hysteresis constraint mechanism is used to check and correct by defining the minimum gap, so as to obtain the dynamic light load threshold and dynamic heavy load threshold applicable to the current working condition. based on , Among the statistical characteristics of mean and standard deviation, the expressions for calculating the dynamic light load threshold and dynamic heavy load threshold in this invention are as follows:

[0015] in, For dynamic light load threshold, For dynamic overload threshold, Standard deviation, This is the preset sensitivity coefficient; To ensure the stability of the system at critical states, the algorithm introduces a hysteresis constraint mechanism, defining a minimum gap, calculated as follows:

[0016] in, The preset hysteresis coefficient is used when the detection is... The system will automatically adjust at that time. ; S5. Based on the current power, dynamic light load threshold and dynamic heavy load threshold, execute the load status judgment output of the three-level discrimination mechanism, and obtain the final load status based on the judgment results of the preset number of times by setting the anti-jitter confirmation mechanism and the auxiliary judgment mechanism. The three-level discrimination mechanism is as follows: when the current power value is detected... When the system determines that it is in a light load state; when When the power value is between two thresholds, the system determines that it is in an overload state; when the power value is between two thresholds, the previous decision result and the current topology are maintained. The auxiliary decision mechanism involves calculating the estimated load resistance value in real time. With the preset load resistance threshold The comparison is as follows: At that time, it was determined to be a light load. When this occurs, it is determined to be an overload.

[0017] S6. Optimal topology mapping and switching condition check: Based on the final load state, the switch is determined when the change in the final load state exceeds the minimum switching time. The SP topology is selected for light load state and the SS topology is selected for heavy load state, thus completing the adaptive load identification algorithm. The topology switching process of this invention follows strict safety guidelines. When the load status is confirmed to have changed and the time since the last switch exceeds the preset minimum switching interval, the system performs a topology switching operation.

[0018] The specific switching strategy of this invention is based on the mapping relationship between load status and optimal compensation topology. When the load status is identified as light, the SP topology is selected; when the load status is identified as heavy, the SS topology is selected. During the switching process, the system adopts a soft-start strategy.

[0019] A one-to-two wireless power transmission system based on adaptive load identification, characterized in that the one-to-two wireless power transmission system adopts a distributed control architecture including a transmitter and two receivers 1 and 2 with identical structures; The transmitter is powered by a DC power supply. High-frequency inverter circuit, fixed compensation capacitor and transmitting coil The high-frequency inverter circuit, constructed by sequential connections, includes four MOSFET switching elements. ; Both receiver 1 and receiver 2 include a receiving coil. The circuit consists of a switchable compensation network, a rectifier and filter circuit, a voltage and current sampling circuit, a microcontroller, and a switching execution circuit. The switchable compensation network uses MOSFET switching elements, with a total of four back-to-back MOSFET switching elements at receiver 1 and receiver 2. It switches between two compensation topologies: series SS and parallel SP. The microcontroller runs an adaptive load identification algorithm to determine the load status in real time, generates topology switching control signals, and manages the operating status of the receiving end.

[0020] Beneficial effects of this invention: (1) The adaptive load identification method based on sliding window statistical features proposed in this invention effectively overcomes the problems of misjudgment and frequent switching caused by parameter drift and instantaneous interference in the fixed threshold method through dynamic threshold, hysteresis constraint and anti-jitter confirmation mechanism. The system has strong robustness and is suitable for dynamic and complex working conditions. (2) The present invention adopts a fully distributed control architecture. Each receiving end only needs local voltage and current information to independently complete decision-making and switching. There is no need to communicate with the transmitting end or other receiving ends. The system has a simple structure, low cost, high reliability, and good scalability. (3) The system of the present invention can accurately identify the load status based on locally collected power data through an adaptive algorithm, and automatically switch between SP and SS topologies according to load changes, thereby achieving high average transmission efficiency within a preset wide load range, which is significantly better than fixed topologies. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the one-to-two wireless power transmission system based on adaptive load identification as described in this invention; Figure 2 This is a flowchart of the steps of the one-to-two wireless power transmission system and topology switching method based on adaptive load identification of the present invention; Figure 3 This is a flowchart of the adaptive load identification algorithm described in this invention; Figure 4Figure 1 shows the output power and transmission efficiency of receivers 1 and 2 under the condition of asynchronous change and cross-coupling of load resistance parameters as described in this invention. Figure 2 shows the load resistance change of receivers 1 and 2, Figure 3 shows the output power of receivers 1 and 2, and Figure 4 shows the transmission efficiency of receivers 1 and 2. Figure 5 Figure (a) is a load status identification diagram of receiver 1, Figure (b) is a load status identification diagram of receiver 2, Figure (c) is a compensation topology switching diagram of receiver 1, and Figure (d) is a compensation topology switching diagram of receiver 2. Figure 6 Figure 1 shows the output voltage and current of receivers 1 and 2 according to the present invention. Figure 2 shows the output voltage of receiver 1, Figure 3 shows the output current of receiver 1, Figure 4 shows the output voltage of receiver 2, and Figure 5 shows the output current of receiver 2. Figure 7 Figure 1 shows a comparison of the performance of adaptive topology switching and fixed topology as described in this invention. Figure 2 shows a comparison of the output power of receiver 1, Figure 3 shows a comparison of the transmission efficiency of receiver 1, Figure 4 shows a comparison of the output power of receiver 2, and Figure 5 shows a comparison of the transmission efficiency of receiver 2. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0023] like Figure 1 As shown, this invention presents a one-to-two wireless power transfer system based on adaptive load identification, comprising a transmitter and two independently identical receivers (Receiver 1 and Receiver 2). The transmitter consists of a DC power supply, a high-frequency inverter circuit, and a fixed compensation capacitor. and transmitting coil The components are connected sequentially, including four MOSFET switching elements. Both receiver 1 and receiver 2 include a receiving coil. The system includes a switchable compensation network, a rectifier and filter circuit, a voltage and current sampling circuit, a microcontroller, and a switching execution circuit. The switchable compensation network uses MOSFET switching elements, and the two receivers together comprise four back-to-back MOSFET switching elements. The system switches between series (SS) and parallel (SP) compensation topologies. It employs a distributed control architecture, where each receiver autonomously identifies the load and switches topologies based solely on its local electrical information, without needing to communicate with the transmitter or another receiver. Furthermore, as shown in the diagram... AC voltage at the transmitting end, Alternating current at the transmitting end; The switchable compensation network is implemented using MOSFETs as switching elements. Their low on-resistance and high switching speed characteristics are very suitable for this application. Optocouplers are used to achieve electrical isolation between the control signal and the power circuit, ensuring the safety of the control system and avoiding interference from the power circuit to the control signal.

[0024] In SS topology mode, the compensation capacitor and the receiving coil form a series resonant structure; in SP topology mode, the switchable compensation network is converted into a parallel resonant structure. Although this system is a one-to-two topology, its distributed architecture can be easily expanded to a one-to-many topology.

[0025] like Figure 2 and Figure 3 The flowchart shown illustrates the steps of a one-to-two wireless power transfer system and topology switching method based on adaptive load identification, specifically including the following steps: S1. System power-on initialization and parameter preset; The preset parameters include sliding window length, sensitivity coefficient, hysteresis coefficient, anti-shake confirmation count, and minimum switching time interval; After the system of this invention is powered on, each receiver microcontroller executes an initialization program: setting the default topology of the switchable compensation network to an SP topology of transmitter series-receiver parallel connection; and clearing the sliding window used to store historical power data. In this embodiment, the transmitter adopts a full-bridge inverter topology, which has good power output capability and harmonic suppression characteristics. The operating frequency is set near the resonant point of 85kHz. This frequency value is determined based on the typical operating range of the magnetically coupled resonant wireless power transmission system, which can ensure sufficient transmission distance and effectively control switching losses.

[0026] The transmitting coil is wound with multi-strand excitation wire, and the inductance of the transmitting coil is set to... The preset value of the inductance can reduce the loss caused by the skin effect at high frequencies; the fixed compensation capacitor value is based on the resonance condition formula. The fixed compensation capacitor was calculated. CBB capacitors with excellent high-frequency characteristics are selected to ensure the quality factor of the resonant network. Figure 1 middle, This is the filter capacitor at the transmitter.

[0027] The hardware configuration of each receiver remains consistent, and the inductance of the receiving coil is... The electrical parameters are kept similar to those of the transmitting end; the receiving end compensation capacitor... Receiver 1 compensation capacitor Compensation capacitor at receiver 2 The impedance matching is also determined based on the resonance condition. This parameter value has been optimized using simulation software to ensure optimal impedance matching at the target frequency. For receiver 1 filter capacitor, This is the filter capacitor at the receiver end 2.

[0028] In addition, regarding Figure 1 The rectifier circuit section: The rectifier and filter circuit of receiver 1 consists of diodes. D2, D3, and D4 form a full-bridge rectifier structure; the rectifier and filter circuit of receiver 2 consists of diodes D5, D6, D7, and D8 forming a full-bridge rectifier structure.

[0029] S2. Synchronous acquisition and calculation of voltage and current at the receiving end: Based on each preset fixed sampling interval, the voltage and current at both ends are synchronously acquired through the voltage sampling circuit and current sampling circuit at the receiving end, and the instantaneous output power and power change rate are calculated. In this embodiment, the voltage and current synchronous acquisition stage at the receiving end is achieved through a resistor voltage divider circuit with a division ratio of 10:1. Combined with a 12-bit ADC converter, this enables accurate measurement within the 0-50V input range. The current sampling circuit uses a Hall sensor, with the range determined based on the system's maximum transmission power. The sampling frequency is set to 1kHz to ensure a balance between real-time performance and computational load. Before the signal enters the ADC, this invention incorporates a first-order low-pass filter circuit with a cutoff frequency of 500Hz to effectively suppress the impact of switching noise and high-frequency interference on sampling accuracy.

[0030] like Figure 3 As shown, the implementation of the control algorithm is the core of the entire system. After power-on, the system first enters the initialization phase, setting the default operating state to the SP topology suitable for light load conditions, and simultaneously clearing all historical data within the sliding window. The sliding window size is set to... This value represents a balance between system response speed and state recognition stability. During each sampling period, the system synchronously acquires the output voltage. and output current The instantaneous power and the rate of change of power are obtained through calculation. The expression for calculating the instantaneous power is as follows:

[0031] in, For output current, This refers to the output voltage. The expression for calculating the rate of change of power is:

[0032] in, For instantaneous power, sampling interval .

[0033] S3. Sliding Window Update and Adaptive Threshold Calculation: Based on a sliding window with preset power sampling values, the instantaneous output power and power change rate are input into the sliding window for updating, and the mean, standard deviation, and 25th percentile are calculated. and 75th percentile Statistical characteristics were obtained; This invention employs an analysis method based on power statistical feature extraction for adaptive threshold calculation. The system maintains a sliding window containing the 30 most recent power samples in real time, using a first-in-first-out (FIFO) strategy to ensure data timeliness. Within each calculation cycle, the algorithm first calculates the mean of the power data within the window. This value reflects the system's average power level; then the standard deviation is calculated. This is used to measure the dispersion of power data; it also calculates the 25th percentile. and 75th percentile , and Statistics can effectively characterize the boundary features of power distribution.

[0034] The expression for calculating the mean is:

[0035] in, The preset power sampling value, for index, For the first The power of each power sample value; The expression for calculating standard deviation is:

[0036] in, This is the mean.

[0037] S4. Dynamic load judgment threshold calculation and adaptive correction: Based on statistical characteristics, the dynamic light load threshold and dynamic heavy load threshold are calculated, and the hysteresis constraint mechanism is used to check and correct by defining the minimum gap, so as to obtain the dynamic light load threshold and dynamic heavy load threshold applicable to the current working condition. Based on , The expression for calculating the dynamic light load threshold and dynamic heavy load threshold in this invention is as follows: (Mean and standard deviation)

[0038] in, For dynamic light load threshold, For dynamic overload threshold, Standard deviation, This is the preset sensitivity coefficient; In the dynamic calculation of the threshold for judging light and heavy loads, the sensitivity coefficient is... , which are the optimal parameters determined by the simulation experiment in this embodiment.

[0039] To ensure the stability of the system at the critical state, a hysteresis constraint mechanism is introduced, defining a minimum gap, the calculation expression of which is:

[0040] in, To preset the hysteresis coefficient, When detected The system will automatically adjust at that time. This effectively avoids frequent load switching when the load is at a critical state.

[0041] S5. Based on the current power, dynamic light load threshold and dynamic heavy load threshold, execute the load status judgment output of the three-level discrimination mechanism, and obtain the final load status based on the judgment results of the preset number of times by setting the anti-jitter confirmation mechanism and the auxiliary judgment mechanism. The load status determination process of this invention employs a three-level discrimination mechanism to ensure the accuracy of status identification. When the current power value is detected... When the system determines that it is in a light load state; when When the power value is between two thresholds, the system determines that it is in an overload state; when the power value is between two thresholds, the previous decision result is maintained, that is, the current topology is maintained.

[0042] To improve the system's anti-interference capability, this invention incorporates a de-jitter confirmation mechanism, requiring continuous... A change in load status is confirmed only if the results of the two determinations are consistent. The parameter values ​​can respond promptly to real load changes and effectively filter out misjudgments caused by transient interference.

[0043] In special operating conditions such as system startup or drastic load changes, when the sliding window data is not full or the power change rate exceeds a set threshold, the algorithm will activate an auxiliary decision mechanism based on load resistance estimation. This mechanism calculates the estimated load resistance value in real time. and with the preset load resistance threshold Comparison, At that time, it was determined to be a light load. When the load is determined to be overloaded, the present invention establishes multiple protection mechanisms to ensure the accuracy and reliability of load status identification under various working conditions, thus achieving fast and accurate load status judgment.

[0044] S6. Optimal topology mapping and switching condition check: Based on the final load state, the switch is determined when the change in the final load state exceeds the minimum switching time. The SP topology is selected for light load state and the SS topology is selected for heavy load state, thus completing the adaptive load identification algorithm. The topology switching process of this invention follows strict safety guidelines. A change in load status is confirmed when the time since the last switch exceeds the minimum switching interval. The system will only perform a topology switch operation at that time.

[0045] The specific switching strategy of this invention is based on the mapping relationship between load state and optimal compensation topology. When the load state is identified as light load, the SP topology is selected; when the load state is identified as heavy load, the SS topology is selected. During the switching process, the system adopts a soft-start strategy, which avoids large current surges by gradually adjusting the duty cycle of the switching transistor drive signal, thus ensuring a smooth and reliable switching process.

[0046] To verify the system performance, this invention establishes a complete theoretical analysis model.

[0047] The transmitter impedance can be expressed as:

[0048] in, Represents the equivalent series resistance of the transmitter. The imaginary unit, Angular frequency, The compensation capacitor value for the transmitting coil is fixed. This is the inductance of the transmitting coil.

[0049] Reflection impedance can be expressed as:

[0050] in, The equivalent impedance of the receiving end. Let be the mutual inductance coefficient, where the mutual inductance between the transmitter and receiver coils is defined as . The mutual inductance between the transmitting coil and the receiving coil 2 is The cross-inductance between the coils of receiver 1 and receiver 2 is When analyzing the reflection impedance of each independent receiver, M generally refers to the mutual inductance coefficient of the corresponding branch. The coupling coefficient is... The inductance of the transmitting coil, For the inductance of the receiving end, For the inductance of receiver 1, For the inductance of receiver 2, This is an estimated value for the load resistance. This is the estimated load resistance value for receiver 1. The estimated value of the load resistance at receiver 2. Preset load resistance threshold.

[0051] The system transmission efficiency can be expressed as:

[0052] in, Output power Input power; Based on simulation analysis and theoretical calculations, this implementation achieves high transmission efficiency within a load range of 10-50Ω. Under sudden load changes, the system exhibits excellent dynamic characteristics, with both output power and efficiency recovering to steady-state values ​​within a short time. Particularly in complex operating conditions where the two receivers change asynchronously, the system's distributed control architecture ensures that each receiver operates independently, effectively suppressing the effects of cross-coupling.

[0053] This embodiment adds an anomaly handling mechanism to ensure the safe and reliable operation of the system. When the output voltage exceeds 48V or the output current exceeds 2A, the system will immediately lock the current topology and record the abnormal state. If three consecutive switching failures are detected, the system will automatically switch to SS safety mode to ensure that the basic power transmission function is not affected. The anomaly mechanism ensures equipment safety by monitoring system operating parameters in real time. When the system detects that the output voltage or current exceeds the safety threshold, it immediately stops topology switching and maintains the current topology, while recording the abnormal state to provide complete data support for subsequent fault analysis. During system operation, if multiple consecutive topology switching operations fail, the system will automatically switch to a preset safe operation mode. In this mode, the system will continue to operate using a verified reliable compensation topology to ensure that the basic power transmission function is not affected. The switching failures include: abnormal drive signals, switching transistor failures, open or short circuits in the compensation network, and voltage and current exceeding limits due to load changes.

[0054] To verify the effectiveness of this invention in scenarios with dynamic load and multiple receivers, the following... Figures 4 to 7 The experimental results of this invention in terms of load change recognition, adaptive topology switching, output stability, and performance comparison are presented respectively.

[0055] like Figure 4As shown in the figure, Figure (a) is the load resistance variation curve over time, simulating the independent dynamic changes of the loads at receiver 1 and receiver 2; Figures (b) and (c) are the output power and transmission efficiency response curves for receiver 1 and receiver 2, respectively. The experimental results show the overall transmission efficiency variation curve of the system. Throughout the entire test period, the system efficiency remained at a high level (average efficiency of 83.5%) with minimal fluctuations. This directly verifies that the method described in this invention can maintain the overall high efficiency and stable operation of the system when dealing with asynchronous and dynamic changes in multiple loads.

[0056] like Figure 5 The figure illustrates the working process of the load state identification and adaptive topology switching mechanism proposed in this invention. Figures (a) and (b) show the load state identification results of receiver 1 and receiver 2, respectively, demonstrating that the system can identify the load type in real time. Figures (c) and (d) show the compensation topology switching sequence triggered by receiver 1 and receiver 2 based on the identification results. The system can dynamically adjust the resonant topology structure according to the load state to match the optimal transmission conditions.

[0057] like Figure 6 The figures show the output voltage and current waveforms of receiver 1 and receiver 2 under adaptive topology switching. Figures (a) and (b) show the output voltage and current of receiver 1, and Figures (c) and (d) show the output voltage and current of receiver 2. Experimental results show that the output voltage and current remain continuous and smooth throughout the entire asynchronous load change and topology switching process, without voltage spikes or current surges caused by hard switching. This indicates that the soft-start and isolation drive strategy adopted in this invention effectively ensures the dynamic safety and power quality of the system.

[0058] like Figure 7 As shown, the performance of the adaptive topology switching method proposed in this invention is compared with that of a fixed topology. Figures (a) and (c) compare the output power of receiver 1 and receiver 2 under the two methods, respectively; Figures (b) and (d) compare the transmission efficiency. Experimental data show that, in scenarios with dynamic load changes, the adaptive topology switching method significantly outperforms the fixed topology in both output power and transmission efficiency, especially during periods of sudden load changes.

[0059] It should be noted that the specific parameter values ​​given in this embodiment are typical values ​​derived from theoretical analysis and simulation verification, and can be appropriately adjusted according to specific needs in practical applications. Through this meticulously designed hardware platform and intelligent control algorithm, the system can achieve efficient and stable operation over a wide load range, providing a reliable solution for the practical application of one-to-two wireless power transmission systems.

Claims

1. A pair of two wireless power transfer system based on adaptive load identification, characterized in that, The one-to-two wireless power transmission system adopts a distributed control architecture, including one transmitter and two receivers 1 and 2 with identical structures. The transmitting end is supplied by a direct current power supply , a high frequency inverter circuit, a fixed compensation capacitor and a transmitting coil are connected in sequence, the high frequency inverter circuit comprises four MOSFET switching elements ​ Both receiver 1 and receiver 2 include a receiving coil. The circuit consists of a switchable compensation network, a rectifier and filter circuit, a voltage and current sampling circuit, a microcontroller, and a switching execution circuit. The switchable compensation network uses MOSFET switching elements, with a total of four back-to-back MOSFET switching elements at receiver 1 and receiver 2. It switches between two compensation topologies: series SS and parallel SP. The microcontroller runs an adaptive load identification algorithm to determine the load status in real time, generates topology switching control signals, and manages the operating status of the receiving end.

2. A topology switching method for a one-to-two wireless power transmission system based on adaptive load identification, characterized in that, Includes the following steps: S1. System power-on initialization and parameter preset; The preset parameters include sliding window length, sensitivity coefficient, hysteresis coefficient, anti-shake confirmation count, and minimum switching time interval; S2. Based on each preset fixed sampling interval, the voltage and current at both ends are synchronously collected through the voltage sampling circuit and current sampling circuit at the receiving end, and the instantaneous output power and power change rate are calculated. S3. Based on a sliding window with preset power sampling values, update the instantaneous output power and power change rate by inputting them into the sliding window, and calculate the mean, standard deviation, and 25th percentile. and 75th percentile Statistical characteristics were obtained; The adaptive threshold calculation employs power statistical feature extraction. The statistical characteristics include: mean, standard deviation, and 25th percentile. and 75th percentile ; S4. Based on statistical characteristics, the dynamic light load threshold and dynamic heavy load threshold are calculated, and the minimum gap is defined to perform hysteresis constraint mechanism for checking and correction, so as to obtain the dynamic light load threshold and dynamic heavy load threshold applicable to the current working condition. S5. Based on the current power, dynamic light load threshold and dynamic heavy load threshold, execute the load status judgment output of the three-level discrimination mechanism, and obtain the final load status based on the judgment results of the preset number of times by setting the anti-jitter confirmation mechanism and the auxiliary judgment mechanism. The three-level discrimination mechanism is as follows: when the current power value is detected... When the system determines that it is in a light load state; when When the power value is between two thresholds, the system determines that it is in an overload state; when the power value is between two thresholds, the previous decision result and the current topology are maintained. The auxiliary decision mechanism involves calculating the estimated load resistance value in real time. With the preset load resistance threshold The comparison is as follows: At that time, it was determined to be a light load. When this occurs, it is determined to be an overload; S6. Based on the final load status, the algorithm determines whether the final load status change exceeds the minimum switching time. For light load status, the SP topology is selected and for heavy load status, the SS topology is selected, thus completing the adaptive load identification algorithm.

3. The topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, In S2, the voltage sampling circuit is specifically implemented through a resistor voltage divider circuit with a voltage division ratio of 10:

1. The expression for calculating the instantaneous power is: ； in, For output current, This refers to the output voltage. The expression for calculating the power change rate is: ； in, Instantaneous power This is the preset sampling interval.

4. The topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, In step S4, the expressions for calculating the dynamic light load threshold and the dynamic heavy load threshold are as follows: ； in, For dynamic light load threshold, For dynamic overload threshold, Standard deviation, To preset the sensitivity coefficient, It is the 25th percentile. It is at the 75th percentile.

5. The topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, In step S4, a hysteresis constraint mechanism is used to check and correct the behavior by defining a minimum gap. The expression for the minimum gap is defined as follows: ； in, To preset the hysteresis coefficient, The mean; The hysteresis constraint mechanism specifically checks and corrects when it detects... The system will automatically adjust at that time. , For dynamic light load threshold, This is the dynamic overload threshold.

6. The topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, In S5, the three-level discrimination mechanism is as follows: when the current power value is detected... When the system determines that it is in a light load state; when When the power value is between two thresholds, the system determines that it is in an overload state; when the power value is between two thresholds, the previous decision result and the current topology are maintained.

7. The topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, In S5, the auxiliary decision mechanism is to calculate the estimated load resistance value in real time. With the preset load resistance threshold The comparison is as follows: At that time, it was determined to be a light load. When this occurs, it is determined to be an overload.

8. A topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, The method includes an anomaly handling mechanism that ensures device safety by monitoring system operating parameters in real time. When the system detects that the output voltage or current exceeds the safety threshold, it immediately stops topology switching and maintains the current topology, while recording the abnormal state.

9. A topology switching method for a one-to-two wireless power transmission system based on adaptive load identification according to claim 2, characterized in that, The method uses an adaptive load identification algorithm to automatically select the SP topology under light load conditions and the SS topology under heavy load conditions.

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