A wireless charging receiving system supporting multiple protocols

Abstract

The present invention discloses a wireless charging receiving system supporting multiple protocols, which relates to the technical field of wireless charging. The system includes a signal acquisition module, a protocol detection module, an impedance adjustment module, and a rectification control module. The signal acquisition module acquires an alternating magnetic field signal and generates a fundamental frequency I signal and a fundamental frequency Q signal through orthogonal transformation. The protocol detection module analyzes the fundamental frequency I signal and the fundamental frequency Q signal by using a multi-scale decomposition method and outputs the type of charging protocol. The impedance adjustment module adjusts a variable impedance network according to the type of charging protocol to generate optimal matching parameters. The rectification control module controls the switching timing of a full-bridge rectifier circuit based on the optimal matching parameters and outputs a stable charging power. Through the collaborative cooperation of the signal acquisition module, the protocol detection module, the impedance adjustment module, and the rectification control module, the present invention constructs a receiving system supporting multiple wireless charging standards, improving the compatibility and reliability of wireless charging.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging, and particularly to a wireless charging receiving system supporting multiple protocols. Background Art

[0002] Existing wireless charging systems face protocol compatibility challenges. Currently, there are multiple wireless charging standards in the market, such as Qi, AirFuel, PMA, etc. Each standard adopts different communication protocols and matching mechanisms, resulting in the inability to achieve universal charging for electronic devices of different brands and models. This protocol fragmentation not only increases the complexity of device interoperability but also significantly raises the user's usage cost, restricting the popularization and application of wireless charging technology.

[0003] There are defects in the impedance matching technology of traditional wireless charging receiving systems. Existing solutions generally adopt static or simple impedance adjustment methods and cannot accurately adapt to the dynamic charging requirements of different charging protocols and devices. Due to the lack of an intelligent impedance matching algorithm, the system is difficult to optimize charging parameters in real time, resulting in low charging efficiency, large energy conversion losses, and obvious power fluctuations during the charging process, seriously affecting the user experience and battery life. Summary of the Invention

[0004] In view of the problems of poor protocol compatibility and low impedance matching efficiency of existing wireless charging systems, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention lies in how to design an intelligent and efficient multi - protocol wireless charging receiving system to improve the compatibility and reliability of wireless charging.

[0006] To solve the above - mentioned technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a wireless charging receiving system supporting multiple protocols, which includes a signal acquisition module, a protocol detection module, an impedance adjustment module, and a rectification control module, wherein: the signal acquisition module acquires an alternating magnetic field signal and generates a fundamental - frequency I signal and a fundamental - frequency Q signal through orthogonal transformation; the protocol detection module analyzes the fundamental - frequency I signal and the fundamental - frequency Q signal by using a multi - scale decomposition method and outputs the type of charging protocol; the impedance adjustment module adjusts a variable impedance network according to the type of charging protocol to generate optimal matching parameters, wherein the variable impedance network includes a switched - capacitor array and a switched - inductor array; the rectification control module controls the switching timing of a full - bridge rectifier circuit based on the optimal matching parameters and outputs a stable charging power.

[0008] As a preferred solution of the multi - protocol - supported wireless charging receiving system of the present invention, the signal acquisition module is provided with an oscillation unit, a first quadrature unit, a second quadrature unit, a first filtering unit, a second filtering unit, a first gain unit and a second gain unit, wherein: the oscillation unit generates a first local oscillator signal and a second local oscillator signal with a 90 - degree phase difference; the first quadrature unit multiplies the alternating magnetic field signal by the first local oscillator signal, and the second quadrature unit multiplies the alternating magnetic field signal by the second local oscillator signal; the first filtering unit performs band - pass filtering on the output of the first quadrature unit, and the second filtering unit performs band - pass filtering on the output of the second quadrature unit; the first gain unit amplifies the output of the first filtering unit to obtain a base - frequency I signal, and the second gain unit amplifies the output of the second filtering unit to obtain a base - frequency Q signal.

[0009] As a preferred solution of the multi - protocol - supported wireless charging receiving system of the present invention, the processing flow of the protocol detection module is as follows: decompose the base - frequency I signal and the base - frequency Q signal by using wavelet transform to obtain frequency - domain eigenvalues; establish a spectrum distribution map according to the frequency - domain eigenvalues and extract a sequence of feature points; input the sequence of feature points into a convolutional neural network to obtain a protocol matching probability; determine the type of charging protocol through threshold decision according to the protocol matching probability.

[0010] As a preferred solution of the multi - protocol - supported wireless charging receiving system of the present invention, the convolutional neural network includes: an input layer arranges the sequence of feature points into a feature matrix; a convolutional layer performs two - dimensional convolutional operations on the feature matrix to extract local features; a pooling layer performs maximum sampling on the local features; a fully - connected layer outputs the probability distribution of each charging protocol; a decision layer selects the charging protocol corresponding to the maximum probability as the type of charging protocol.

[0011] As a preferred solution of the multi - protocol - supported wireless charging receiving system of the present invention, the impedance adjustment module includes: determine the target impedance range according to the type of charging protocol; configure the initial switch states of the switched - capacitor array and the switched - inductor array; sample the input voltage and input current and calculate the current input impedance value; compare the current input impedance value with the target impedance range and calculate the required impedance adjustment amount; based on a preset step value and the adjustment amount, adjust the switch states of the switched - capacitor array and the switched - inductor array in sequence; determine the switch - state combination at the optimal impedance match through an iterative optimization algorithm and calculate the corresponding equivalent capacitance value and equivalent inductance value; substitute the equivalent capacitance and equivalent inductance values into the impedance matching model to obtain the optimal matching parameters.

[0012] As a preferred embodiment of the multi - protocol - supported wireless charging receiving system of the present invention, the rectification control module includes: connecting an energy - storage capacitor in parallel at the output end of the full - bridge rectification circuit to construct a voltage - doubler rectification structure; detecting the output voltage of the voltage - doubler rectification structure; determining the optimal conduction angle of the rectification switch based on the optimal matching parameters and generating a gate drive signal corresponding to the conduction angle; judging the deviation value between the output voltage and the reference voltage through a comparator; dynamically adjusting the duty cycle of the gate drive signal according to the deviation value through a PI control algorithm; controlling the rectification switch with the adjusted gate drive signal and outputting a stable charging power.

[0013] As a preferred embodiment of the multi - protocol - supported wireless charging receiving system of the present invention, the optimal matching parameters include resonance frequency, quality factor, coupling coefficient, and rectification angle.

[0014] The beneficial effects of the present invention are as follows: The present invention uses orthogonal transformation to convert high - frequency alternating magnetic - field signals into base - frequency I / Q signal pairs containing complete amplitude - phase information, providing a reliable data basis for protocol identification; combines multi - scale wavelet decomposition and a convolutional neural network based on the VGG structure for protocol identification, and designs a probability evaluation module with a caching mechanism to comprehensively analyze consecutive multiple judgment results, improving the accuracy and anti - interference ability of protocol identification; constructs a variable impedance network using a binary - weighted switched - capacitor array and a switched - inductor array, and realizes precise impedance adjustment through a binary - search strategy based on the target impedance interval; adopts a voltage - doubler rectification structure with an energy - storage capacitor in parallel, combines conduction - angle control based on optimal matching parameters and dynamic duty - cycle adjustment of the PI algorithm to achieve stable charging - power output. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a system architecture diagram of a multi - protocol - supported wireless charging receiving system.

[0017] Figure 2 It is a flowchart of the signal acquisition module of a multi - protocol - supported wireless charging receiving system.

[0018] Figure 3 It is a flowchart of the impedance adjustment module of a multi - protocol - supported wireless charging receiving system.

[0019] Figure 4 It is a flowchart of the rectification control module of a multi - protocol - supported wireless charging receiving system. Detailed Embodiments

[0020] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings of the specification.

[0021] In the following description, many specific details are set forth to facilitate a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0022] Secondly, the so-called "one embodiment" or "embodiment" herein refers to specific features, structures, or characteristics that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0023] Embodiment 1. Refer to Figures 1 to 4 , which is the first embodiment of the present invention. This embodiment provides a wireless charging receiving system that supports multiple protocols. The system architecture diagram is as shown in Figure 1 , and it includes a signal acquisition module, a protocol detection module, an impedance adjustment module, and a rectification control module. The specific structures and working processes of each module are described in detail below.

[0024] The signal acquisition module process is as shown in Figure 2 . The signal acquisition module acquires the alternating magnetic field signal and generates the fundamental frequency I signal and the fundamental frequency Q signal through orthogonal transformation. The alternating magnetic field signal is obtained by induction of the receiving coil. The receiving coil is designed with a rectangular flattened structure and is wound with enameled copper wire. The receiving coil converts the alternating magnetic field generated by the transmitting end into an alternating voltage signal. The amplitude range of this signal is 0.5V - 5V, and the frequency is the same as the operating frequency of the transmitting end, which is 100 - 200kHz.

[0025] Specifically, the signal acquisition module is provided with an oscillation unit, a first orthogonal unit, a second orthogonal unit, a first filtering unit, a second filtering unit, a first gain unit, and a second gain unit. The oscillation unit generates a first local oscillator signal and a second local oscillator signal with a phase difference of 90 degrees. Among them, the oscillation unit adopts a phase-locked loop circuit based on a quartz crystal, outputs a reference clock with a frequency of 200kHz. This reference clock signal passes through a frequency division circuit composed of D flip-flops to obtain two orthogonal signals, and the phase difference error is controlled within ±3 degrees. The amplitude of the output signal is 3.3V, and it has high frequency stability.

[0026] The first quadrature unit multiplies the alternating magnetic field signal by the first local oscillator signal, and the second quadrature unit multiplies the alternating magnetic field signal by the second local oscillator signal. Specifically, the first quadrature unit multiplies the alternating magnetic field signal by the first local oscillator signal to generate a sum frequency component and a difference frequency component. The frequency of the sum frequency component is about 200 - 400 kHz, and the frequency of the difference frequency component is in the range of 0 - 50 kHz. The second quadrature unit multiplies the alternating magnetic field signal by the second local oscillator signal and also generates a sum frequency component and a difference frequency component. Since the phase difference between the two local oscillator signals is 90 degrees, the phase difference between the difference frequency components output by the two quadrature units is also 90 degrees, forming a quadrature relationship.

[0027] The first filtering unit performs band - pass filtering on the output of the first quadrature unit, and the second filtering unit performs band - pass filtering on the output of the second quadrature unit. Specifically, the first filtering unit and the second filtering unit use second - order Butterworth active band - pass filters to suppress the high - frequency sum frequency components and retain the difference frequency components. The two filtered signals still maintain a 90 - degree phase difference, and the amplitudes are more smoothed after being shaped by the filters.

[0028] The first gain unit amplifies the output of the first filtering unit to obtain the fundamental frequency I signal, and the second gain unit amplifies the output of the second filtering unit to obtain the fundamental frequency Q signal. Specifically, the first gain unit amplifies the difference frequency I component output by the first filtering unit, and the adjustable gain range is 5 - 20 times. After amplification and level adjustment, a fundamental frequency I signal with a peak value of 3V is obtained. The second gain unit performs the same gain amplification on the difference frequency Q component output by the second filtering unit to obtain a fundamental frequency Q signal that is orthogonal to the I signal. These two fundamental frequency signals carry the amplitude and phase information of the original alternating magnetic field signal and can be used for subsequent protocol feature extraction.

[0029] Through the processing of the above - mentioned signal acquisition module, the high - frequency alternating magnetic field signal is converted into a pair of fundamental frequency I / Q signals containing complete amplitude and phase information through orthogonal transformation. The I signal reflects the in - phase component of the original signal, and the Q signal reflects the quadrature component of the original signal. Together, they form a complex representation that describes the original signal. This method of orthogonal transformation not only reduces the bandwidth requirements for subsequent processing but also retains all the characteristic information of the signal, providing a reliable data basis for protocol recognition.

[0030] The protocol detection module uses the multi - scale decomposition method to analyze the fundamental frequency I signal and the fundamental frequency Q signal and outputs the charging protocol type. The fundamental frequency I signal and Q signal are sampled by a 16 - bit ADC. The sampling rate is set to 500 kHz to ensure meeting the requirements of the Nyquist sampling theorem. The sampling time window is 10 ms, and 5000 sampling points are obtained in each time window.

[0031] Specifically, the processing flow of the protocol detection module includes: First, wavelet transform is used to decompose the baseband I signal and the baseband Q signal to obtain frequency-domain eigenvalue. Specifically, the db4 wavelet basis function is used for 3-layer wavelet decomposition, and after decomposition, 3 detail coefficient sequences and 1 approximation coefficient sequence are obtained. For the decomposition results of each layer, statistics such as energy feature, standard deviation, and mean are calculated to form preliminary eigenvalues. At the same time, the maximum value, minimum value of the wavelet coefficients and their occurrence positions are extracted as supplementary eigenvalues. These eigenvalues (preliminary eigenvalues and supplementary eigenvalues) together constitute a 64-dimensional frequency-domain feature vector.

[0032] Second, a spectrum distribution map is established based on the frequency-domain eigenvalues, and a sequence of feature points is extracted. The 64-dimensional frequency-domain feature vector is rearranged in the form of 8×8 to construct a two-dimensional spectrum distribution matrix. In this matrix, key feature points are extracted by calculating features such as local extreme points, energy aggregation regions, and spectrum transition bands. The specific extraction process includes: detecting the position points where the energy density exceeds the preset threshold, recording their coordinates and amplitudes; calculating the centroid position of the spectrum; marking the boundary points of the spectrum bandwidth. Finally, a 32×32 sequence matrix of feature points is obtained.

[0033] Then, the sequence of feature points is input into a convolutional neural network to obtain the protocol matching probability. This convolutional neural network adopts a typical VGG structure, but is optimized for the characteristics of wireless charging protocols: First, the 32×32 sequence matrix of feature points is used as the network input; then feature extraction is performed through 3 convolutional blocks, each convolutional block contains 2 3×3 convolutional layers and 1 2×2 max pooling layer; finally, classification is completed through 2 fully connected layers. Among them, the first convolutional block uses 16 convolutional kernels, the second uses 32, and the third uses 64. The ReLU activation function is used in the convolutional layer, and the max pooling strategy is used in the pooling layer.

[0034] Finally, according to the protocol matching probability, the type of charging protocol is determined through threshold decision. The protocol matching probability threshold is set to 0.75. When the matching probability of a certain protocol type exceeds this threshold, a comprehensive determination is made in combination with the consistency of the results of 3 consecutive decisions to improve the recognition reliability. If the matching probabilities of all protocol types are lower than the threshold, a secondary decision mechanism is started: calculate the ratio of the highest probability value to the second highest probability value. When this ratio exceeds 1.5, select the protocol type corresponding to the highest probability; otherwise, mark the signal as an unknown protocol type and trigger the resampling analysis process.

[0035] Among them, the specific implementation of the convolutional neural network is as follows: The input layer arranges the feature point sequence into a feature matrix; the convolutional layer performs two-dimensional convolutional operations on the feature matrix to extract local features; the pooling layer performs maximum sampling on the local features to reduce the data dimension; the fully connected layer outputs the probability distribution of each charging protocol; the decision layer selects the charging protocol corresponding to the maximum probability as the charging protocol type. Among them, the decision layer implements a probability evaluation module with a caching mechanism to comprehensively analyze the results of 5 consecutive decisions. When the same protocol type appears in the cache more than 3 times and the average probability value exceeds 0.85, it is finally confirmed as that protocol type. This mechanism effectively improves the reliability of the decision and reduces misjudgments caused by instantaneous interference.

[0036] Through the processing of the above-mentioned protocol detection module, time-frequency analysis is performed on the fundamental frequency I / Q signal based on multi-scale wavelet decomposition, and rich feature information is extracted. This module uses the db4 wavelet basis function for three-layer decomposition to obtain multi-dimensional feature vectors such as energy features and statistical features, and effectively characterizes the frequency domain characteristics of the signal through a two-dimensional spectrum distribution matrix. Innovatively, a convolutional neural network based on the VGG structure is introduced, and deep extraction and classification of protocol features are realized through three convolutional blocks and two fully connected layers. At the same time, a probability evaluation module with a caching mechanism is designed to comprehensively analyze the results of multiple consecutive decisions, and a reliable protocol recognition mechanism is established. This processing scheme combining multi-scale analysis and deep learning not only improves the accuracy of protocol recognition, but also enhances the robustness of the system to interference, laying a foundation for the compatibility of multi-protocol wireless charging.

[0037] The flowchart of the impedance adjustment module is as Figure 3 shown. The impedance adjustment module adjusts the variable impedance network according to the charging protocol type to generate optimal matching parameters, where the variable impedance network includes a switched-capacitor array and a switched-inductor array.

[0038] Specifically, the working process of the impedance adjustment module includes: First, according to the charging protocol type, determine the target impedance range. Specifically, by looking up the pre-stored protocol parameter table, obtain the standard impedance range corresponding to this protocol, and for unknown protocols, obtain the corresponding impedance range through matching in the feature database. Second, configure the initial switch states of the switched-capacitor array and the switched-inductor array. The switched-capacitor array consists of multiple binary-weighted capacitor units, and the switched-inductor array consists of multiple binary-weighted inductor units. In the initial state, all switches are placed in the off state.

[0039] Then, sample the input voltage and input current, and calculate the current input impedance value. Use a high-precision ADC to synchronously sample the input voltage and current. After the sampled data is averaged and filtered, the magnitude and phase of the current impedance are obtained through complex number operations. Next, compare the current input impedance value with the target impedance range, and calculate the required impedance adjustment amount. Determine the adjustment direction according to the relationship between the impedance magnitude and the target range, and judge the type of network to be adjusted according to the impedance phase angle. When the phase angle is positive, the capacitor array is preferentially adjusted; when it is negative, the inductor array is preferentially adjusted.

[0040] Subsequently, based on the preset step value and adjustment amount, sequentially adjust the switching states of the switched-capacitor array and the switched-inductor array. Adopt a binary search strategy and try bit by bit starting from the highest-order switch. Wait for the system to stabilize after each adjustment before performing impedance measurement. Determine the final state of the current switch by comparing the impedance change trends before and after the adjustment. Then, determine the combination of switching states when the impedance is optimally matched through an iterative optimization algorithm, and calculate the corresponding equivalent capacitance value and equivalent inductance value. Take the error between the impedance magnitude and the target value as the optimization goal, record the combination of switching states that meet the accuracy requirements, and calculate the equivalent parameters of the network according to the switching states.

[0041] Finally, substitute the equivalent capacitance and equivalent inductance values into the impedance matching model to obtain the optimal matching parameters, where the above optimal matching parameters include the resonant frequency, quality factor, coupling coefficient, and rectification angle.

[0042] In practical applications, to ensure the stability of the charging process, the response time of the impedance adjustment process is controlled within 50 ms. The system realizes fast impedance adjustment to meet the requirements of dynamic charging scenarios through parallel processing algorithm optimization and critical path speedup.

[0043] In addition, the construction process of the impedance matching model is as follows: Based on the principle of the resonant circuit, the receiving end forms a series resonant network through a switched-capacitor array, a switched-inductor array, and a load resistor. Among them, the load resistor characterizes the effective load characteristics of the wireless charging receiving end. Use the complex domain analysis method to model the resonant network. The equivalent capacitance, equivalent inductance, and load resistor form an impedance link, and the passband characteristics of the received signal are determined by the impedance characteristics of the resonant network. According to Kirchhoff's law of circuits, write the voltage relationship formula of the resonant network, deduce the complex transfer function of the network, analyze the frequency response characteristics of the network, and establish the mapping relationship between frequency and network impedance. Based on the principle of the minimum reflection coefficient, transform the matching problem between the load impedance and the source impedance into an optimization problem, and establish an impedance matching model with the reflection coefficient as the optimization goal. Introduce a quality factor correction term to consider the loss effect of the resonant network and improve the impedance matching model. This model can be used to calculate the matching parameters for given equivalent capacitance and equivalent inductance values.

[0044] By adopting a binary-weighted switched-capacitor array and a switched-inductor array to construct a variable impedance network, combined with a binary search strategy and an iterative optimization algorithm based on the target impedance range, precise and controllable regulation of impedance is achieved. This module synchronously samples the input voltage and current through a high-precision ADC to obtain the current impedance value, intelligently selects the type of regulation network according to the impedance phase angle, and introduces an impedance matching model with quality factor correction to handle the influence of resonant network losses. Finally, the optimal matching parameters are output, providing an efficient and precise impedance matching scheme for multi-protocol wireless charging systems.

[0045] The flow chart of the rectification control module is as Figure 4 shown. The rectification control module controls the switching timing of the full-bridge rectifier circuit based on the optimal matching parameters to output a stable charging power.

[0046] Specifically, the working process of the rectification control module includes: First, a storage capacitor is connected in parallel at the output end of the full-bridge rectifier circuit to construct a voltage-doubling rectification structure. The storage capacitor uses a capacitor with a low equivalent series resistance. This voltage-doubling rectification structure includes four power switching tubes of the full-bridge rectifier circuit and the parallel storage capacitor, which is used to rectify and boost the input AC voltage into a DC voltage. Second, the output voltage of the voltage-doubling rectification structure is detected. A voltage-dividing detection circuit is used to collect the output voltage signal in real time. The divided voltage signal is input into the analog-to-digital conversion unit of the controller after signal conditioning to obtain the actual output voltage value.

[0047] Then, based on the optimal matching parameters, the best conduction angle of the rectification switch is determined, and a gate drive signal corresponding to the conduction angle is generated. The switching period is calculated according to the resonant frequency, and the best conduction moment is determined by combining the quality factor and the coupling coefficient. Four complementary gate drive signals are generated through a phase-shifting link. Next, a comparator is used to judge the deviation value between the output voltage and the reference voltage. The reference voltage is selected according to the type of charging protocol. The output deviation signal of the comparator represents the charging state, and when the deviation exceeds the preset range, the control parameter adjustment is triggered.

[0048] Subsequently, according to the deviation value, the duty cycle of the gate drive signal is dynamically adjusted through a PI control algorithm. The PI controller calculates the control quantity according to the deviation value. The proportional coefficient determines the adjustment speed, and the integral coefficient is used to eliminate the steady-state error. The control quantity is mapped to a duty cycle adjustment signal. At the same time, the system adopts an adaptive parameter adjustment strategy based on the type of charging protocol and the load change characteristics to dynamically optimize the proportional coefficient and the integral coefficient of the PI controller, improving the adaptability of the system to different charging scenarios.

[0049] Finally, the rectification switch is controlled by using the adjusted gate drive signal, and a stable charging power is output. The gate drive signal modulated by the duty cycle controls the conduction timing of the power switching tube to realize the regulation of the output power, so that the output voltage is stabilized within the target value range.

[0050] By adopting a voltage - doubling rectification structure with energy - storage capacitors in parallel, combining the conduction - angle control based on optimal matching parameters and the duty - cycle dynamic regulation of the PI algorithm, the precise controllability of the output power is achieved. This module determines the optimal conduction moment according to the resonance frequency, quality factor, and coupling coefficient, generates complementary drive signals through a phase - shift link, and adjusts the duty cycle in real - time based on the output - voltage deviation, ultimately realizing a stable charging - power output and providing an efficient and precise rectification control scheme for the multi - protocol wireless - charging system.

[0051] In summary, the present invention uses orthogonal transformation to convert high - frequency alternating magnetic - field signals into a pair of fundamental - frequency I / Q signals containing complete amplitude - phase information, providing a reliable data basis for protocol recognition; combines multi - scale wavelet decomposition and a convolutional neural network based on the VGG structure for protocol recognition, and designs a probability - evaluation module with a caching mechanism to comprehensively analyze consecutive multiple judgment results, improving the accuracy and anti - interference ability of protocol recognition; constructs a variable - impedance network using a binary - weighted switched - capacitor array and a switched - inductor array, and realizes precise impedance adjustment through a binary - search strategy based on the target impedance interval; adopts a voltage - doubling rectification structure with energy - storage capacitors in parallel, combines the conduction - angle control based on optimal matching parameters and the duty - cycle dynamic regulation of the PI algorithm, and realizes a stable charging - power output.

[0052] Example 2, referring to Figures 1 to 4 This is the second embodiment of the present invention. This embodiment provides a multi - protocol - supported wireless - charging receiving system. To verify the beneficial effects of the present invention, scientific demonstration is carried out through economic - benefit calculation and simulation experiments.

[0053] To verify the feasibility and performance of the technical solution of the present invention, a complete simulation - experiment platform is built. The experiment platform consists of a transmitting test system and a receiving test system.

[0054] In the test of the signal - acquisition module, the receiving coil is designed with a 45μH flattened structure, an inner diameter of 45mm, an outer diameter of 68mm, and 22 turns of coil. After testing, within the coupling - distance range of 540mm, the amplitude of the induced voltage of the receiving coil is 0.8V - 4.2V. The pair of fundamental - frequency I / Q signals output by the signal - acquisition module is observed through an oscilloscope. The signal amplitude is stable at 2.8V - 3.1V, and the phase difference between the two signals is controlled within the range of 87° - 92°, meeting the requirements of subsequent processing.

[0055] The performance test of the protocol detection module adopted test signals containing three mainstream protocols, namely Qi, PMA, and A4WP. Each protocol contained 1000 groups of test samples. The test results showed that under normal working conditions (coupling coefficient greater than 0.3), the recognition accuracies of the system for the three protocols reached 98.2%, 97.5%, and 96.8% respectively. When there were amplitude fluctuations of ±20% or phase deviations of ±10°, the recognition accuracy could still be maintained above 93%. The average system response time was 42 ms, and the maximum did not exceed 65 ms. To illustrate the advantages of the present invention in terms of performance indicators, a comparative analysis was carried out with the existing technical solutions, and the comparison results are shown in Table 1.

[0056] Table 1 Performance Comparison between the Method of the Present Invention and the Traditional Pattern Matching Algorithm

[0057]

[0058] From the comparison data in Table 1, it can be seen that the protocol recognition scheme of the present invention using the multi-scale decomposition method combined with the convolutional neural network has obvious advantages in key indicators such as protocol recognition accuracy, system response time, and impedance adjustment accuracy compared with the traditional pattern matching algorithm. Especially while maintaining a high power efficiency, it achieves a faster response speed and a more precise impedance matching.

[0059] The impedance adjustment module adopts an 8-bit binary weighted switched capacitor array and a switched inductor array. The capacitance adjustment range is 1 pF to 256 pF, with a step value of 1 pF; the inductance adjustment range is 0.1 μH to 25.6 μH, with a step value of 0.1 μH. In actual tests, the system can complete the impedance matching process within 45 ms, and the matching accuracy is better than ±2.5%. When the load impedance changes by ±30%, the system can reach the optimal matching state again within one control cycle.

[0060] The rectification control module uses power MOSFETs from IR Company to construct a full-bridge rectification circuit, with a on-resistance of 20 mΩ, and the switching frequency is synchronized with the transmitting end. The energy storage capacitor selects a low-ESR electrolytic capacitor of 150 μF / 35V. At a nominal output power of 5W, the output voltage of the system is stable within the range of 5V ± 0.1V, and the ripple coefficient is less than 1%. By dynamically adjusting the duty cycle through the PI control algorithm, the adjustment time of the system for a sudden increase / decrease of 50% load does not exceed 2 ms, and the overshoot is controlled within 5%.

[0061] The overall system performance test was carried out in the power range of 0.5W to 15W, with the test environment temperature of 25°C and relative humidity of 65%. The results show that under the rated working conditions, the overall power conversion efficiency of the system reaches 86.5%, among which the rectification efficiency is 89.3% and the modulation efficiency is 96.8%. The system has good compatibility with three mainstream protocols, can automatically identify the protocol type and complete parameter optimization, and the average time taken for the whole process from detection to stable charging is 125ms.

[0062] The long-term stability test was continuously carried out for 1000 hours. During this period, the system worked at a rated power of 10W, and the performance parameters were recorded every 1 hour. The test results show that the fluctuation ranges of all performance indicators of the system are controlled within ±3%, and there are no significant performance decays or faults, verifying the reliability and stability of the system design.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A wireless charging receiving system supporting multiple protocols, characterized in that: It includes a signal acquisition module, a protocol detection module, an impedance adjustment module and a rectification control module, wherein: The signal acquisition module acquires the alternating magnetic field signal and generates a baseband I signal and a baseband Q signal through orthogonal transformation; The protocol detection module analyzes the baseband I signal and the baseband Q signal, and outputs a charging protocol type; The impedance adjustment module adjusts the variable impedance network according to the charging protocol type to generate optimal matching parameters, wherein the variable impedance network includes a switched capacitor array and a switched inductor array; The rectifier control module controls the switching timing of the full-bridge rectifier circuit based on the optimal matching parameters to output stable charging power; The processing flow of the protocol detection module is as follows: Decomposing the baseband I signal and the baseband Q signal by wavelet transform to obtain frequency domain eigenvalues; Establish a frequency spectrum distribution diagram according to the frequency domain characteristic values ​​and extract a characteristic point sequence; Inputting the feature point sequence into a convolutional neural network to obtain a protocol matching probability; According to the protocol matching probability, the charging protocol type is determined by threshold judgment: The convolutional neural network comprises: The input layer arranges the feature point sequence into a feature matrix; The convolution layer performs a two-dimensional convolution operation on the feature matrix to extract local features; The pooling layer performs maximum sampling on the local features; The fully connected layer outputs the probability distribution of each charging protocol; The decision layer selects the charging protocol corresponding to the maximum probability as the charging protocol type.

2. The wireless charging receiving system supporting multiple protocols as claimed in claim 1, characterized in that: The signal acquisition module is provided with an oscillation unit, a first orthogonal unit, a second orthogonal unit, a first filtering unit, a second filtering unit, a first gain unit and a second gain unit, wherein: The oscillation unit generates a first local oscillation signal and a second local oscillation signal with a phase difference of 90 degrees; The first orthogonal unit multiplies the alternating magnetic field signal with the first local oscillator signal, and the second orthogonal unit multiplies the alternating magnetic field signal with the second local oscillator signal; The first filtering unit performs bandpass filtering on the output of the first orthogonal unit, and the second filtering unit performs bandpass filtering on the output of the second orthogonal unit; The first gain unit amplifies the output of the first filtering unit to obtain the baseband I signal, and the second gain unit amplifies the output of the second filtering unit to obtain the baseband Q signal.

3. The wireless charging receiving system supporting multiple protocols as claimed in claim 1, characterized in that: The impedance adjustment module comprises: Determining a target impedance range according to the charging protocol type; configuring the initial switching states of the switched capacitor array and the switched inductor array; Sample the input voltage and input current, and calculate the current input impedance value; Compare the current input impedance value with the target impedance range to calculate the required impedance adjustment amount; Based on the preset step value and the adjustment amount, sequentially adjusting the switch states of the switch capacitor array and the switch inductor array; The switch state combination for optimal impedance matching is determined through an iterative optimization algorithm, and the corresponding equivalent capacitance and equivalent inductance values ​​are calculated; Substituting the equivalent capacitance and equivalent inductance values ​​into the impedance matching model, the optimal matching parameters are obtained.

4. The wireless charging receiving system supporting multiple protocols as claimed in claim 1, characterized in that: The rectifier control module comprises: Connecting an energy storage capacitor in parallel to the output end of the full-bridge rectifier circuit to construct a voltage doubling rectifier structure; Detecting the output voltage of the voltage doubler rectifier structure; Based on the optimal matching parameters, determining the optimal conduction angle of the rectifier switch, and generating a gate drive signal corresponding to the conduction angle; Determining the deviation value between the output voltage and the reference voltage by a comparator; According to the deviation value, dynamically adjusting the duty cycle of the gate drive signal through a PI control algorithm; The regulated gate drive signal is used to control the rectifier switch and output stable charging power.

5. The wireless charging receiving system supporting multiple protocols as claimed in claim 4, characterized in that: The optimal matching parameters include resonance frequency, quality factor, coupling coefficient and rectification angle.

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