A wireless sensor ac-dc conversion method and system based on zero voltage switching

Abstract

This application discloses a method and system for AC-DC conversion of a wireless sensor based on zero-voltage switching, relating to the field of power conversion technology. The method involves acquiring the power supply control signal of the wireless sensor when power transmission is interrupted; modulating the power supply control signal and the conversion control signal according to the power balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch before conduction; adjusting the compensation voltage limit of the main power switch within the switching cycle according to the conduction triggering rule, and determining the conduction voltage threshold of the main power switch when it is turned on at zero voltage based on the compensation voltage limit; determining the switching feedback amplitude of the main power switch after it completes zero-voltage turn-on based on the conduction control signal and the conduction voltage threshold, and gradually restoring the DC operating voltage of the wireless sensor. This application can achieve coordinated control of the zero-voltage turn-on and power supply restoration of the main power switch to improve the reliability of node wake-up during AC-DC conversion.

Description

Technical Field

[0001] This application relates to the field of power conversion technology, and more specifically, to a wireless sensor AC-DC conversion method and system based on zero-voltage switching. Background Technology

[0002] Power conversion is fundamental in power electronics for achieving energy transformation, electrical parameter matching, and precise control of power supply status. It is a core component of power supply systems for various electronic devices. For the power supply requirements of low-power wireless sensor nodes, power conversion for AC-DC scenarios focuses on converting AC power input from the grid into DC power required by the wireless sensor via a power conversion link. Simultaneously, it adapts and adjusts the input voltage amplitude and fluctuation range to output stable and controllable rated DC power. This is achieved through the on / off timing control of power switching devices, enabling efficient energy conversion and transmission and providing reliable power support for the wireless sensor's operation under all conditions.

[0003] However, in traditional AC-DC conversion processes of wireless sensors based on zero-voltage switches, the lack of a full-link timing matching mechanism during the sleep and wake-up switching process leads to a disconnect between the main power switch's conduction control and zero-voltage turn-on constraints, as well as the node's power supply balance requirements. This results in low zero-voltage turn-on efficiency of the switch and severe voltage fluctuations during the wake-up process, making it difficult to guarantee the stability of the power supply for the wireless sensor's wake-up. Therefore, how to achieve coordinated control of the main power switch's zero-voltage turn-on and power supply recovery to improve the reliability of node wake-up during AC-DC conversion is a problem facing the industry. Summary of the Invention

[0004] This application provides a wireless sensor AC-DC conversion method and system based on zero-voltage switching, which can realize coordinated control of zero-voltage turn-on and power supply restoration of the main power switch to improve the reliability of node wake-up during AC-DC conversion.

[0005] This application provides a wireless sensor AC-DC conversion method based on zero-voltage switching, comprising the following steps: When the wireless sensor enters sleep mode, acquire the power control signal of the wireless sensor when power transmission is cut off. Determine the switching control signal when the wireless sensor wakes up from sleep mode. Modulate the power supply control signal and the switching control signal according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before it is turned on. When the voltage of the main power switch drops to zero voltage, the conduction triggering rule of the main power switch when it is turned on is determined. The compensation voltage limit of the main power switch during the switching cycle is adjusted according to the conduction triggering rule, and then the conduction voltage threshold of the main power switch when it is turned on at zero voltage is determined by the compensation voltage limit. Based on the conduction control signal of the main power switch of the wireless sensor before conduction and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, the switching feedback amplitude after the main power switch completes the zero voltage turn-on is determined, and the DC operating voltage of the wireless sensor is gradually restored through the switching feedback amplitude.

[0006] Furthermore, the power supply control signal refers to the instruction signal that controls the on / off state of the power supply link of the wireless sensor and the power transmission timing, and determines the on / off logic of the power supply circuit.

[0007] Furthermore, the specific process for determining the switching control signal when the wireless sensor wakes up from sleep mode is as follows: Based on the node energy state characteristics of all wireless sensors, construct the energy state parameters of the wireless sensors when they are in sleep mode; The energy loss gradient during the current wake-up transition is determined by the energy state parameters and the energy conversion efficiency during the corresponding wireless sensor wake-up transition. The switching control signal for waking the wireless sensor from sleep mode is determined based on the energy loss gradient.

[0008] Furthermore, the specific process of obtaining the conduction control signal of the main power switch of the wireless sensor before conduction by demand modulation of the power supply control signal and the conversion control signal through the power supply balance demand of the wireless sensor is as follows: Based on the power balance requirements of wireless sensors and the current load power consumption of wireless sensors, power balance characteristic parameters are constructed. Phase matching is performed on the power supply control signal and the conversion control signal based on the power supply balance characteristic parameters to obtain the power supply balance modulation coefficient; The conversion control signal is pulse-width modulated by the power supply balance modulation coefficient to generate a pre-conduction reference signal before conduction. By performing a logical AND operation between the pre-conduction reference signal and the power supply control signal, the conduction control signal of the main power switch of the wireless sensor before conduction is obtained.

[0009] Furthermore, the specific process for determining the conduction triggering rule of the main power switch when it is turned on is as follows: Based on the timing characteristics of the main power switch voltage dropping to zero voltage point, a zero voltage point state vector is constructed. The conduction time window of the main power switch after the zero voltage point is determined by the zero voltage point state vector and the current resonant period parameter. From the conduction time window, determine the conduction triggering rule of the main power switch when it is turned on.

[0010] Furthermore, the specific process for adjusting the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule is as follows: Based on the conduction triggering rules and the current switching cycle parameters of the main power switch, a voltage compensation feature vector within the cycle is constructed. The amount of compensation voltage adjustment is determined by the voltage compensation eigenvector within the cycle and the energy transfer efficiency of the resonant converter. Extract the compensation voltage limit of the main power switch during the switching cycle from the compensation voltage adjustment.

[0011] Furthermore, based on the conduction control signal of the main power switch of the wireless sensor before conduction and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, the specific process of determining the switching feedback amplitude of the main power switch after it completes zero voltage turn-on is as follows: Based on the conduction control signal of the main power switch before conduction and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, the initial conduction state vector of the main power switch after zero voltage is extracted. Based on the initial conduction state vector and the energy transfer characteristics of the resonant converter, the feedback adjustment coefficient after zero-voltage turn-on is determined. The preset reference feedback amplitude is dynamically corrected by the feedback adjustment coefficient to generate the switching feedback amplitude after the main power switch completes zero-voltage turn-on.

[0012] Furthermore, the conduction voltage threshold refers to the critical voltage criterion for the main power switch to achieve zero-voltage turn-on. Only when the drain-source voltage of the main power switch is lower than the conduction voltage threshold is the output of the turn-on trigger signal allowed.

[0013] Furthermore, the conduction control signal refers to the signal that controls the conduction timing, conduction pulse width, and initial conduction amplitude of the main power switch.

[0014] A wireless sensor AC-DC conversion system based on zero-voltage switching is provided for performing the aforementioned wireless sensor AC-DC conversion method based on zero-voltage switching. The conversion system includes: The acquisition module is used to acquire the power supply control signal of the wireless sensor when the power transmission is cut off when the wireless sensor enters sleep mode. The modulation module is used to determine the switching control signal when the wireless sensor wakes up from the sleep mode. It modulates the power supply control signal and the switching control signal according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before it is turned on. The processing module is used to determine the conduction triggering rule of the main power switch when the voltage of the main power switch drops to zero voltage point, adjust the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule, and then determine the conduction voltage threshold of the main power switch when it is turned on at zero voltage based on the compensation voltage limit. The execution module is used to determine the switching feedback amplitude of the main power switch after it completes zero-voltage turn-on, based on the conduction control signal of the main power switch before it is turned on and the conduction voltage threshold of the main power switch when it is turned on at zero voltage. The DC operating voltage of the wireless sensor is gradually restored through the switching feedback amplitude.

[0015] This application discloses a wireless sensor AC-DC conversion method and system based on zero-voltage switching, which has the following advantages: When the wireless sensor enters sleep mode, the power supply control signal of the wireless sensor when power transmission is cut off is acquired; the switching control signal when the wireless sensor wakes up from sleep mode is determined, and the power supply control signal and the switching control signal are modulated according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch before conduction; when the voltage of the main power switch drops to zero voltage, the conduction triggering rule of the main power switch when conducting is determined, and the compensation voltage limit of the main power switch during the switching cycle is adjusted according to the conduction triggering rule, and then the conduction voltage threshold of the main power switch when zero voltage is turned on is determined by the compensation voltage limit; the switching feedback amplitude after the main power switch completes zero voltage turn-on is determined according to the conduction control signal and the conduction voltage threshold, and the DC operating voltage of the wireless sensor is gradually restored by the switching feedback amplitude.

[0016] Therefore, in this application, the DC operating voltage of the wireless sensor is gradually restored through the switch feedback amplitude. Specifically, by determining the conduction control signal before conduction, a pre-conduction control reference for the main power switch transistor, matching the power supply balance requirements of the wireless sensor and adapting to the sleep-wake-up switching sequence, is obtained. This establishes a stable and controllable initial conduction boundary for the recovery process of the wireless sensor's DC operating voltage, fundamentally avoiding the risks of voltage overshoot and drop caused by conduction timing misalignment and power overload. It ensures accurate adaptation between the initial conduction state of the main power switch transistor and the load power-on sequence during the wake-up process, providing a compliant initial control reference for the subsequent closed-loop calculation of the switch feedback amplitude, and significantly improving the convergence speed and controllability of the voltage recovery closed-loop control. By determining the conduction voltage threshold at zero-voltage turn-on, a critical conduction judgment benchmark that adapts to the real-time operating conditions of the main power switch and ensures reliable zero-voltage turn-on can be obtained. This completely eliminates the conduction losses and conduction current surges of the switch caused by non-zero voltage turn-on, ensuring that the main power switch is in a low-loss, high-stability operating state throughout the entire conduction process. It avoids voltage distortion and operating condition fluctuations during conduction, providing distortion-free, true conduction state data for subsequent acquisition of switch feedback amplitude, and significantly improving the closed-loop control accuracy of the DC operating voltage recovery process.

[0017] In summary, the technical solution adopted in this application can achieve coordinated control of zero-voltage turn-on and power supply restoration of the main power switching transistor, thereby improving the reliability of node wake-up during AC-DC conversion. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this embodiment of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an exemplary flowchart of a wireless sensor AC-DC conversion method based on zero-voltage switching provided in this application; Figure 2 This is a flowchart illustrating the determination of the conduction control signal provided in this application; Figure 3 This is a flowchart illustrating the process for determining the on-state voltage threshold provided in this application; Figure 4 This is a schematic diagram of the timing sequence of the key signal for zero-voltage turn-on of the main power switch provided in this application; Figure 5 This is a schematic diagram of voltage recovery and feedback control under the sleep-wake condition of a wireless sensor provided in this application; Figure 6This is a module structure diagram of a wireless sensor AC-DC conversion system based on zero-voltage switching provided in this application.

[0020] Reference numerals: 100, acquisition module; 200, modulation module; 300, processing module; 400, execution module. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] This application provides a wireless sensor AC-DC conversion method and system based on zero-voltage switching, the core of which includes the following steps: S1: When the wireless sensor enters sleep mode, acquire the power supply control signal of the wireless sensor when power transmission is cut off; S2: Determine the switching control signal when the wireless sensor wakes up from sleep mode, and modulate the power supply control signal and the switching control signal according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before conduction. S3: When the voltage of the main power switch drops to zero voltage, determine the conduction triggering rule of the main power switch when it is turned on, adjust the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule, and then determine the conduction voltage threshold of the main power switch when it is turned on at zero voltage by the compensation voltage limit. S4: Based on the conduction control signal of the main power switch of the wireless sensor before conduction and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, determine the switching feedback amplitude after the main power switch completes the zero voltage turn-on, and gradually restore the DC operating voltage of the wireless sensor through the switching feedback amplitude.

[0023] Steps S1 / S2 / S3 / S4 are executed sequentially; Example 1: To better understand the above technical solution, the following will provide a detailed description of the technical solution in conjunction with the accompanying drawings and specific implementation methods. (Refer to...) Figure 1 As shown in the figure, this is an exemplary flowchart of a wireless sensor AC-DC conversion method based on a zero-voltage switch according to this embodiment of the present application. The conversion method includes the following steps: In step S1, when the wireless sensor enters sleep mode, the power supply control signal of the wireless sensor when power transmission is cut off is acquired.

[0024] In practice, firstly, when the microcontroller unit built into the wireless sensor node detects that the preset sleep trigger condition is met, the low-power management module built into the wireless sensor node outputs a sleep mode start command, and simultaneously sends a power transmission cut-off command for non-essential functional modules to the power management chip of the wireless sensor node's power supply system. At the synchronous moment when the power management chip performs the cut-off operation, the target signal is acquired through a synchronous signal acquisition circuit composed of a high-speed voltage comparator and a sample-and-hold circuit. The high-speed voltage comparator compares the power supply control signal with the reference voltage in real time. When the level of the power supply control signal jumps from a high level in the power-on state to a low level in the cut-off state, the output edge triggers the sample-and-hold circuit, latching the level timing, transition slope, and cut-off delay duration of the power supply control signal at the cut-off moment, thus completing the acquisition of the power supply control signal.

[0025] It should be noted that, in this application, the power supply control signal refers to the instruction signal that controls the on / off state of the power supply link of the wireless sensor and the power transmission timing, and determines the on / off logic of the power supply circuit.

[0026] In step S2, the switching control signal when the wireless sensor wakes up from sleep mode is determined. The power supply control signal and the switching control signal are modulated according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before conduction.

[0027] In this embodiment, determining the switching control signal when the wireless sensor wakes up from sleep mode can be achieved through the following steps: Based on the node energy state characteristics of all wireless sensors, construct the energy state parameters of the wireless sensors when they are in sleep mode; The energy loss gradient during the current wake-up transition is determined by the energy state parameters and the energy conversion efficiency during the corresponding wireless sensor wake-up transition. The switching control signal for waking the wireless sensor from sleep mode is determined based on the energy loss gradient.

[0028] In specific implementation, firstly, the power detection unit of the power management chip built into the wireless sensor node collects data on the node's remaining power, static power consumption of the sleep module, and power supply loop loss for the three consecutive working cycles before sleep triggering at a low power sampling frequency of 1Hz as node energy state characteristics. The collected characteristic data is then input into a known moving average filtering module to remove abnormal sampling values. Following a preset parameter mapping rule, sleep-time energy state parameters, including remaining available energy, sleep standby power consumption, and minimum wake-up energy threshold, are generated. Next, the energy conversion efficiency during the wireless sensor's wake-up transition is calibrated using a device power consumption calibration method. A fixed efficiency value under the corresponding node hardware operating conditions is obtained and stored in the on-chip non-volatile memory. The energy state parameters are acquired, and the difference between the remaining available energy and the minimum wake-up energy threshold is extracted as the wake-up available energy margin. Based on the energy conversion efficiency, a piecewise linear calculation method is used to calculate the maximum allowable energy loss within each step of the wake-up process, according to equal time steps. A linear fitting method is then used to fit the maximum allowable energy loss to obtain the energy loss gradient during the current wake-up transition. Finally, based on the energy loss gradient as the calculation boundary, the maximum allowable power ramp-up limit within each timing step during the wake-up process is determined. The power limit corresponding to each timing step is mapped to the corresponding duty cycle parameter of the pulse width modulation module built into the microcontroller unit. The duty cycle and the power limit have a positive linear correlation. According to the timing sequence of the wake-up process, the duty cycle parameter corresponding to each timing step is written into the corresponding register of the pulse width modulation module to generate a wake-up transition control signal that is perfectly matched to the energy loss gradient and has a continuous timing sequence.

[0029] It should be noted that, in this application, the node energy state characteristics refer to the set of characteristics representing the remaining power level of the wireless sensor node, the static power consumption of the sleep unit, and the inherent losses of the power supply circuit, as well as the energy carrying and consumption attributes; the energy state parameters represent the energy carrying capacity and wake-up constraint boundary of the wireless sensor in the sleep state; the energy conversion efficiency is the proportion of input electrical energy converted into effective working electrical energy of the load during the transition from sleep to wake-up of the wireless sensor; the energy loss gradient refers to the maximum allowable energy loss per unit time step during the wake-up transition of the wireless sensor; and the conversion control signal refers to the command signal that controls the power supply of the wireless sensor during the transition from sleep mode to wake-up mode.

[0030] Preferably, in this embodiment, the power supply control signal and the conversion control signal are modulated according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before conduction, referring to... Figure 2 As shown in the figure, this is a flowchart illustrating the process of determining the conduction control signal in some embodiments of this application. In this embodiment, the determination of the conduction control signal can be achieved using the following steps: In step S21, power balance characteristic parameters are constructed based on the power balance requirements of the wireless sensor and the current load power consumption of the wireless sensor. In step S22, the power supply control signal and the conversion control signal are phase matched according to the power supply balance characteristic parameters to obtain the power supply balance modulation coefficient; In step S23, the conversion control signal is pulse-width modulated by the power supply balance modulation coefficient to generate a pre-conduction reference signal before conduction. In step S24, the pre-conduction reference signal and the power supply control signal are logically ANDed to obtain the conduction control signal of the main power switch of the wireless sensor before conduction.

[0031] In specific implementation, firstly, the power consumption detection module built into the wireless sensor microcontroller unit collects real-time load power consumption data of each functional module during the wake-up process, with the sampling frequency perfectly matching the module power-on timing step size. Simultaneously, it calls the power balance requirements pre-stored in non-volatile memory to extract three core constraints: the maximum allowable voltage fluctuation threshold, the power ramp-up rate limit, and the timing matching error threshold. The collected current load power consumption and constraint parameters are input into a normalization processing module. After unifying the dimensions of the parameters, a power balance characteristic parameter including power matching coefficients, voltage fluctuation limits, and timing constraint windows is constructed. Then, using the timing constraint window in the power balance characteristic parameter as the matching boundary, the effective transition edges of the power supply control signal and the conversion control signal are extracted as phase reference points through a zero-crossing detection circuit. Using the phase reference point of the power supply control signal as the reference zero point, the phase difference between the phase reference point and the reference zero point of the conversion control signal is calculated. The phase difference is compared with the timing matching error threshold in the power balance characteristic parameter, and a phase matching correction value is obtained through proportional calculation. After normalization processing combined with the power matching coefficient, a power balance modulation coefficient in the range of 0 to 1 is obtained. Next, the register of the built-in pulse width modulation module of the microcontroller is called to read the initial pulse width parameter and period parameter of the original conversion control signal; the power supply balance modulation coefficient is multiplied by the initial pulse width parameter to obtain the modulated target pulse width parameter. The value range of the target pulse width does not exceed the period length of the original conversion control signal and is not less than the minimum conduction pulse width threshold of the main power switch; the target pulse width parameter is written into the corresponding register of the pulse width modulation module, and the signal output timing is set within the preset pre-window before the main power switch is turned on to generate a continuous and stable pre-conduction reference signal. Finally, the pre-conduction reference signal and the power supply control signal are respectively connected to the two input terminals of a digital logic AND gate circuit known in the art, or input to the digital logic operation unit built into the microcontroller unit; the effective level of both signals is set to high level, and the rule of the logic AND operation is that the output terminal outputs a high-level valid signal only when both input signals are high level at the same time, and outputs a low-level invalid signal in other states; the signal output by the logic AND operation is subjected to Schmitt trigger shaping to eliminate signal edge jitter, and the conduction control signal before the main power switch is turned on is obtained with timing and pulse width perfectly matching the power supply balance requirements.

[0032] It should be noted that, in this application, power supply balance requirement refers to the dynamic matching relationship between the input power of the power supply circuit and the power consumed by the load during the sleep-wake-up switching process of the wireless sensor; demand modulation refers to the process of adapting the power supply control signal and the conversion control signal to the operating conditions based on the power supply balance requirement of the wireless sensor; current load power consumption is the real-time power consumption value when each functional module is powered on in stages during the wake-up process of the wireless sensor; power supply balance characteristic parameters are the power matching boundary, timing constraint range and voltage fluctuation limit of the power supply circuit of the wireless sensor; phase matching is the alignment of the timing phase of the power supply control signal and the conversion control signal to eliminate the timing discrepancies between the two signals. The sequence misalignment ensures that the timing of the two signals conforms to the power supply balance constraint in the signal matching process. The power supply balance modulation coefficient characterizes the phase matching degree and amplitude adjustment ratio of the two control signals. The pre-conduction reference signal refers to the reference timing and pulse width reference provided before the main power switch is turned on, which conforms to the power supply balance constraint. The turn-on control signal refers to the signal that controls the turn-on timing, turn-on pulse width, and initial turn-on amplitude of the main power switch. The logic AND operation performs synchronization verification between the pre-conduction reference signal and the power supply control signal, and outputs a valid signal only when both signals are at a valid level, ensuring that the timing and level of the final turn-on control signal fully meet the constraint requirements of the two signals.

[0033] In step S3, after the voltage of the main power switch drops to zero voltage, the conduction triggering rule of the main power switch when it is turned on is determined. The compensation voltage limit of the main power switch during the switching cycle is adjusted according to the conduction triggering rule, and then the conduction voltage threshold of the main power switch when it is turned on at zero voltage is determined by the compensation voltage limit.

[0034] In this embodiment, the conduction triggering rule for the main power switch when it is turned on can be determined by the following steps: Based on the timing characteristics of the main power switch voltage dropping to zero voltage point, a zero voltage point state vector is constructed. The conduction time window of the main power switch after the zero voltage point is determined by the zero voltage point state vector and the current resonant period parameter. The conduction triggering rule for the main power switch when it is turned on is determined from the conduction time window.

[0035] In specific implementation, a high-precision differential voltage sampling circuit connected in parallel with the drain-source of the main power switch continuously acquires real-time values ​​of the voltage drop process of the main power switch at a sampling frequency no less than 10 times the operating frequency of the main power switch. A zero-crossing detection circuit identifies the critical moment when the voltage drops to zero, extracting three types of timing features: voltage drop slope, zero voltage arrival time, and initial zero voltage duration. The extracted features are normalized according to a preset dimension order to generate a zero-voltage point state vector containing three dimensions: timing position, voltage amplitude, and state duration. Then, a resonant period detection circuit acquires three types of current resonant period parameters: the current resonant period, resonant half-cycle duration, and resonant voltage zero-crossing time of the resonant cavity in the power supply circuit where the main power switch is located, storing them in the on-chip register of the microcontroller unit. The zero voltage arrival time in the zero-voltage point state vector is used as the starting reference for the window, and combined with the current resonant period parameters, the window termination time is determined to be a preset safety margin time before the end of the resonant half-cycle after the zero voltage arrival time. This timing interval is determined as the conduction time window of the main power switch after the zero voltage point. Finally, using the start and end times of the conduction time window as the core timing constraint boundary, the effective output range of the conduction trigger signal is determined to be the middle 80% timing range within the window, avoiding voltage fluctuation ranges at the window edges. Based on the rated parameters specified in the main power switch device manual, two types of level constraints are determined: minimum effective level and minimum effective pulse width of the trigger signal. Pre-state constraints of zero voltage state being continuously effective before triggering and no overcurrent abnormality in the power supply circuit are added. By integrating the timing conditions, level conditions, and pre-state constraints, the conduction triggering rules of the main power switch when it is turned on are obtained.

[0036] It should be noted that, in this application, the zero-voltage point refers to the critical criterion for the main power switch to achieve lossless zero-voltage turn-on. It is the node where the voltage between the drain and source of the main power switch drops to the critical potential of 0V. The switch is triggered to turn on only within the effective timing range corresponding to this node, which can completely eliminate the voltage and current overlap loss when the switch is turned on. The timing characteristic refers to the time change law of the drain-source voltage of the main power switch from the high level of the off state to the zero-voltage point. The zero-voltage point state vector refers to the state information of the main power switch when it reaches the zero-voltage point. The current resonant period parameter is the complete resonant period duration and resonant state change law of the resonant cavity of the power supply circuit where the main power switch is located. The conduction time window refers to the effective timing range for the main power switch to meet the zero-voltage turn-on condition. The turn-on triggering rule refers to the timing condition, level condition and state precondition that constrain the turn-on triggering action of the main power switch.

[0037] In this embodiment, adjusting the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule can be achieved by the following steps: Construct a voltage compensation feature vector within a cycle based on the conduction triggering rule and the current switching cycle parameters of the main power switch. The amount of compensation voltage adjustment is determined by the voltage compensation characteristic vector within the cycle and the energy transfer efficiency of the resonant converter. The compensation voltage limit of the main power switch during the switching cycle is extracted from the compensation voltage adjustment.

[0038] In specific implementation, firstly, pre-stored conduction triggering rules are invoked to extract three types of constraint parameters: conduction time window boundary, trigger timing margin, and minimum effective pulse width. The current switching cycle parameters of the main power switch are acquired through the microcontroller's timer module, including four core values: current switching cycle, conduction duration, turn-off duration, and switching frequency. The constraint parameters and current switching cycle parameters are normalized according to a preset dimension order to eliminate dimensional differences, thus constructing a voltage compensation feature vector within the cycle that includes timing constraints, cycle state, and trigger boundary dimensions. Then, using efficiency calibration methods in this field, the energy transfer efficiency of the resonant converter under all operating conditions is pre-calibrated, generating operating condition-efficiency mapping data and storing it in the microcontroller's non-volatile memory. The constructed voltage compensation feature vector within the cycle is invoked to extract the operating state parameters of the current switching cycle, and the energy transfer efficiency of the resonant converter under the corresponding operating condition is obtained by looking up the data. Based on the timing constraints and trigger boundary parameters in the voltage compensation feature vector within the cycle, a voltage correction value, i.e., the compensation voltage adjustment, is calculated through linear proportional operations to offset parasitic voltage drop and efficiency loss. Finally, the two types of safety boundary parameters, namely the maximum rated gate voltage and the maximum permissible voltage deviation from zero-voltage turn-on, as specified in the main power switch device manual, are called. The calculated compensation voltage adjustment is compared with the safety boundary parameters, and the smaller value between the compensation voltage adjustment and the maximum permissible voltage deviation from zero-voltage turn-on is taken as the basic limit. Combined with the timing constraints in the turn-on triggering rules, a safety margin of up to 5% can be set on the basis of the basic limit to obtain the compensation voltage limit of the main power switch during the switching cycle.

[0039] It should be noted that, in this application, the current switching cycle parameter refers to the operating state of the main power switch within the current operating cycle; the voltage compensation feature vector within the cycle refers to the core constraints and state characteristics affecting the voltage compensation effect within the switching cycle; the energy transfer efficiency refers to the proportion of input electrical energy converted into output electrical energy under the current operating condition of the quantified resonant converter; the resonant converter refers to the power conversion device that provides power conversion and energy transmission for the main power supply circuit of the wireless sensor, provides the resonant operating condition basis for the zero-voltage turn-on of the main power switch, and determines the operating efficiency and power supply stability of the power supply circuit; the compensation voltage adjustment amount refers to the voltage correction value required to offset the voltage deviation caused by line parasitic parameters, inherent voltage drop of devices, and transmission loss; the compensation voltage limit refers to defining the maximum allowable boundary of voltage compensation within the switching cycle, ensuring that the compensation voltage can offset the voltage deviation of the line and devices, while not exceeding the constraint range of zero-voltage conduction and the safety rating of the devices.

[0040] Preferably, in this embodiment, the turn-on voltage threshold of the main power switch at zero voltage turn-on is determined by the compensation voltage limit, with reference to... Figure 3 As shown in the figure, this is a schematic flowchart of determining the turn-on voltage threshold in some embodiments of this application. In this embodiment, determining the turn-on voltage threshold can be achieved by the following steps: In step S31, the voltage offset characteristic before zero-voltage turn-on is extracted based on the compensation voltage limit and the parasitic capacitance parameter of the main power switch. In step S32, a dynamic adjustment factor for the turn-on voltage is determined based on the voltage offset characteristic and the current load state of the resonant converter. In step S33, the preset reference voltage threshold is nonlinearly corrected by the dynamic adjustment factor to generate a transient conduction threshold for zero-voltage turn-on. In step S34, stability constraints are applied based on the transient turn-on threshold and the turn-off time window of the main power switch to obtain the turn-on voltage threshold of the main power switch when it is turned on at zero voltage.

[0041] In practice, firstly, the nominal capacitance value of the drain-source parasitic capacitance in the off-state is extracted from the official device datasheet of the main power switch. The capacitance value is calibrated under actual operating conditions using the LCR impedance test method, and the calibration result is stored in the non-volatile memory of the microcontroller unit. The compensation voltage limit is used as the maximum allowable offset boundary. Combined with the known RC circuit model of parasitic capacitance charging and discharging, the voltage deviation value caused by the parasitic capacitance before turn-on is calculated. The real-time drain-source voltage before turn-on is collected by the differential sampling circuit and compared with the ideal zero voltage to obtain the actual offset value, that is, the voltage offset characteristic quantity before zero voltage turn-on. Next, a high-precision current-sensing resistor and differential sampling circuit connected in series with the output of the resonant converter are used to acquire the real-time output load current of the resonant converter at a sampling frequency completely synchronized with the switching cycle of the main power switch. The current load power is obtained through the power calculation formula, and the current load state of the resonant converter is determined. The voltage offset feature is called up to extract the ratio of the actual voltage offset value to the maximum allowable offset boundary. Combined with the severity level of the load state, a dynamic adjustment factor for the conduction voltage, ranging from 0 to 1, is obtained through normalization. Then, a preset reference voltage threshold, pre-calibrated under ideal operating conditions and stored in the non-volatile memory of the microcontroller unit, is called up. This preset reference voltage threshold is the ideal critical voltage threshold for zero-voltage turn-on of the main power switch. Using the dynamic adjustment factor as a correction coefficient, a piecewise nonlinear correction model is used to correct the preset reference voltage threshold. The corrected preset reference voltage threshold and the dynamic adjustment factor have a positively correlated nonlinear mapping relationship. The correction process does not exceed the boundary of the compensation voltage limit throughout, and finally, a transient conduction threshold for zero-voltage turn-on is generated. Finally, the turn-off time window of the main power switch in the off state is called to determine the effective timing boundary and effective duration of the zero-voltage state. With the effective timing range of the turn-off time window as the core constraint, the transient conduction threshold is subjected to stability constraints. Transient conduction threshold values ​​that exceed the effective range of the window are eliminated. At the same time, combined with the timing and voltage safety margin reserved by the conduction triggering rules, the transient conduction threshold is limited at the upper and lower levels to ensure that the transient conduction threshold is within the compensation voltage limit throughout the entire process. Finally, the conduction voltage threshold of the main power switch when it is turned on at zero voltage is obtained.

[0042] It should be noted that, in this application, the parasitic capacitance parameter refers to the capacitance characteristic of the inherent parasitic capacitance between the drain-source and gate-source terminals when the main power switch is off; the voltage offset characteristic refers to the deviation characteristic between the actual voltage and the ideal zero voltage caused by the charging and discharging of parasitic capacitance and the line voltage drop before the main power switch is turned on at zero voltage; the load state refers to the real-time power consumption of the wireless sensor load on the output side of the resonant converter; the dynamic adjustment factor is the correction ratio of the turn-on voltage threshold to the voltage offset and load conditions; the preset reference voltage threshold refers to the basic reference for the zero-voltage turn-on conduction voltage threshold; and the nonlinear correction refers to the adjustment of the reference voltage threshold based on the dynamic adjustment factor. The process involves nonlinear adjustments to adapt to actual operating conditions, eliminating threshold deviations caused by voltage offsets and load changes; the transient turn-on threshold refers to the critical value of the temporary turn-on voltage adapted to the current operating conditions; the turn-off time window refers to defining the timing boundary for the continuous effectiveness of the zero-voltage state under the turn-off state of the main power switch; stability constraint refers to the timing compliance verification and voltage boundary limiting of the transient turn-on threshold, eliminating threshold deviations caused by operating condition fluctuations and timing jitter; the turn-on voltage threshold refers to the critical voltage judgment benchmark for the main power switch to achieve zero-voltage turn-on, and the output turn-on trigger signal is only allowed when the drain-source voltage of the main power switch is lower than the turn-on voltage threshold.

[0043] In step S4, the switching feedback amplitude after the main power switch completes zero-voltage turn-on is determined based on the conduction control signal and the conduction voltage threshold, and the DC operating voltage of the wireless sensor is gradually restored through the switching feedback amplitude.

[0044] In this embodiment, determining the switching feedback amplitude after the main power switch completes zero-voltage turn-on based on the turn-on control signal and the turn-on voltage threshold can be achieved through the following steps: The initial conduction state vector of the main power switch after zero voltage turn-on is extracted based on the conduction control signal and the conduction voltage threshold. The feedback adjustment coefficient after zero-voltage turn-on is determined based on the initial conduction state vector and the energy transfer characteristics of the resonant converter. The preset reference feedback amplitude is dynamically corrected by the feedback adjustment coefficient to generate the switching feedback amplitude after the main power switch completes zero-voltage turn-on.

[0045] In specific implementation, firstly, at the start of the first switching cycle after the main power switch completes zero-voltage turn-on, the real-time drain-source on-state voltage drop and on-state current values ​​are simultaneously acquired through a differential voltage sampling circuit connected in parallel with the drain-source of the switch and a current sensing sampling circuit connected in series with the source. The actual on-time timing and on-state pulse width parameters are extracted by calling the on-state control signal, and the on-state critical voltage deviation parameters are extracted by calling the on-state voltage threshold. The parameters acquired and called above are normalized according to a preset dimension to construct an initial on-state vector containing on-state electrical parameters, timing parameters, and deviation parameters. Then, using the operating condition calibration method, the energy transfer characteristics of the resonant converter under full load conditions are calibrated in advance, generating conduction condition-energy transfer efficiency mapping data and storing it in the microcontroller's non-volatile memory. The initial conduction state vector is called to extract the current conduction condition parameters, and the corresponding energy transfer characteristic parameters are obtained from the data. Based on the conduction deviation parameter in the initial conduction state vector, a feedback adjustment coefficient with a value between 0.8 and 1.2 after zero-voltage turn-on is obtained through weighted proportional calculation. Finally, a preset reference feedback amplitude, pre-calibrated under ideal conditions and stored in the microcontroller's non-volatile memory, is called. This preset reference feedback amplitude is a standard reference value adapted to the closed-loop voltage regulation control of the power supply circuit. Using the feedback adjustment coefficient as a correction coefficient, the preset reference feedback amplitude is linearly and dynamically corrected to obtain the initial feedback amplitude. Based on the rated operating parameters of the main power switch and the maximum output limit of the resonant converter, upper and lower limits are set on the initial feedback amplitude, with a safety margin of up to 5% allowed, generating the switching feedback amplitude after the main power switch completes zero-voltage turn-on.

[0046] It should be noted that, in this application, the initial conduction state vector refers to the characteristic of the conduction state at the instant the main power switch completes zero-voltage turn-on; the energy transfer characteristic refers to the law and loss characteristics of the transfer of input and output electrical energy of the resonant converter under the current conduction condition; the feedback adjustment coefficient refers to the correction ratio of the switch feedback amplitude with the conduction state and energy transfer characteristics; the preset reference feedback amplitude refers to the reference benchmark of the switch feedback amplitude; dynamic correction refers to the process of performing condition adaptation calibration on the preset reference feedback amplitude based on the real-time conduction condition after the main power switch is turned on zero-voltage and the energy transfer state of the resonant converter, eliminating the deviation between the fixed reference value and the actual operating state; the switch feedback amplitude refers to the quantified value of the response speed of the smooth recovery of the DC operating voltage of the wireless sensor after the main power switch is turned on.

[0047] In specific implementation, the gradual recovery of the wireless sensor's DC operating voltage through the switch feedback amplitude can be achieved in the following way: After the main power switch completes zero-voltage turn-on, the rated DC operating voltage of the wireless sensor is used as the closed-loop control target. The microcontroller unit uses the real-time acquired switch feedback amplitude as the closed-loop feedback input and sends it to the built-in digital proportional-integral-derivative (DID) control module to perform closed-loop calculations. This DCD control module dynamically adjusts the duty cycle of the main power switch's pulse width modulation signal based on the real-time deviation between the switch feedback amplitude and the preset target reference value, completing voltage recovery in stages: In the initial stage, the maximum adjustment step size of the duty cycle is limited based on the feedback deviation, allowing the output voltage to rise slowly and avoid overshoot; in the linear stage, the adjustment step size is dynamically matched according to the feedback amplitude, causing the output voltage to rise steadily with a constant slope; in the voltage stabilization stage, the adjustment step size is reduced, locking the output voltage within ±1% of the rated DC operating voltage error range, completing the smooth recovery of the DC operating voltage.

[0048] In this embodiment, reference Figure 4 As shown, this figure is a schematic diagram of the timing of key signals for zero-voltage turn-on of the main power switch. The horizontal axis of the figure is the phase angle within the resonant period, in rad, covering the complete phase range of half a resonant period; the vertical axis is the normalized amplitude of the electrical signal, where amplitude 1 corresponds to the rated drain-source voltage of the main power switch under the steady state of turn-off, and amplitude 0 corresponds to the zero-voltage reference potential. Figure 4 In this document, the conduction voltage threshold baseline corresponds to the conduction voltage threshold of the main power switch at zero voltage turn-on, which is the critical threshold for switch turn-on. The conduction time window corresponds to the zero-voltage effective interval within the turn-off time window of the main power switch in the document, which is the only compliant timing range within which the switch is allowed to conduct. The turn-on trigger time corresponds to the turn-on command output time of the switch determined by the turn-on control signal and the conduction voltage threshold in the document, ensuring that the switch completes conduction within the zero-voltage effective interval, thereby eliminating conduction losses and current surges at the source.

[0049] In this embodiment, reference Figure 5 As shown in the figure, this diagram is a schematic diagram of voltage recovery and feedback control under the sleep-wake operation of a wireless sensor. The horizontal axis of the figure is the phase angle of the entire cycle of the operation switching, in rad, covering the complete phase range from sleep mode to wake-up steady state; the vertical axis is the normalized amplitude of the electrical signal, where amplitude 1 corresponds to the upper limit of the system power supply amplitude, amplitude 0.8 corresponds to the rated DC operating voltage of the wireless sensor, and amplitude 0 corresponds to the zero potential reference. Figure 5In this document, the sleep-wake state signal is used to characterize the working mode switching node of the wireless sensor. Its wake-up trigger time is completely synchronized with the output time of the conduction control signal in the specification. The switch feedback amplitude waveform corresponds to the switch feedback amplitude determined after zero voltage turn-on in the specification, which is the core input quantity of the closed-loop control for DC working voltage recovery. The DC working voltage waveform changes synchronously with the switch feedback amplitude, intuitively demonstrating the technical effect of the present invention in achieving stable and gradual voltage recovery through the switch feedback amplitude. This avoids voltage overshoot and drop during the wake-up process, ensuring the power supply stability and low power consumption of the wireless sensor during wake-up.

[0050] Therefore, in this application, the DC operating voltage of the wireless sensor is gradually restored through the switch feedback amplitude. Specifically, by determining the conduction control signal before conduction, a pre-conduction control reference for the main power switch transistor, matching the power supply balance requirements of the wireless sensor and adapting to the sleep-wake-up switching sequence, is obtained. This establishes a stable and controllable initial conduction boundary for the recovery process of the wireless sensor's DC operating voltage, fundamentally avoiding the risks of voltage overshoot and drop caused by conduction timing misalignment and power overload. It ensures accurate adaptation between the initial conduction state of the main power switch transistor and the load power-on sequence during the wake-up process, providing a compliant initial control reference for the subsequent closed-loop calculation of the switch feedback amplitude, and significantly improving the convergence speed and controllability of the voltage recovery closed-loop control. By determining the conduction voltage threshold at zero-voltage turn-on, a critical conduction judgment benchmark that adapts to the real-time operating conditions of the main power switch and ensures reliable zero-voltage turn-on can be obtained. This completely eliminates the conduction losses and conduction current surges of the switch caused by non-zero voltage turn-on, ensuring that the main power switch is in a low-loss, high-stability operating state throughout the entire conduction process. It avoids voltage distortion and operating condition fluctuations during conduction, providing distortion-free, true conduction state data for subsequent acquisition of switch feedback amplitude, and significantly improving the closed-loop control accuracy of the DC operating voltage recovery process.

[0051] In summary, the technical solution adopted in this application can achieve coordinated control of zero-voltage turn-on and power supply restoration of the main power switching transistor, thereby improving the reliability of node wake-up during AC-DC conversion.

[0052] Example 2: This application provides a wireless sensor AC-DC conversion system based on zero-voltage switching, referencing... Figure 6 As shown in the figure, this is a block structure diagram of a wireless sensor AC-DC conversion system based on a zero-voltage switch according to this embodiment of the present application. The conversion system includes: The acquisition module 100 is used to acquire the power supply control signal of the wireless sensor when the power transmission is cut off when the wireless sensor enters the sleep mode. The modulation module 200 is used to determine the switching control signal when the wireless sensor wakes up from the sleep mode. The power supply control signal and the switching control signal are modulated according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before it is turned on. The processing module 300 is used to determine the conduction triggering rule of the main power switch when the voltage of the main power switch drops to zero voltage point, adjust the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule, and then determine the conduction voltage threshold of the main power switch when it is turned on at zero voltage by the compensation voltage limit. The execution module 400 is used to determine the switching feedback amplitude after the main power switch completes zero-voltage turn-on based on the conduction control signal and the conduction voltage threshold, and to gradually restore the DC operating voltage of the wireless sensor through the switching feedback amplitude.

[0053] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0054] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compactdisc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0055] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

Claims

1. A zero-voltage switching based wireless sensor AC-DC conversion method, characterized in that, Includes the following steps: When the wireless sensor enters sleep mode, acquire the power control signal of the wireless sensor when power transmission is cut off. Determine the switching control signal when the wireless sensor wakes up from sleep mode. Modulate the power supply control signal and the switching control signal according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before it is turned on. When the voltage of the main power switch drops to zero voltage, the conduction triggering rule of the main power switch when it is turned on is determined. The compensation voltage limit of the main power switch during the switching cycle is adjusted according to the conduction triggering rule, and then the conduction voltage threshold of the main power switch when it is turned on at zero voltage is determined by the compensation voltage limit. Based on the conduction control signal of the main power switch of the wireless sensor before conduction and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, the switching feedback amplitude after the main power switch completes the zero voltage turn-on is determined, and the DC operating voltage of the wireless sensor is gradually restored through the switching feedback amplitude.

2. The wireless sensor AC-DC conversion method based on zero-voltage switching according to claim 1, characterized in that, The power supply control signal refers to the instruction signal that controls the on / off state of the power supply link of the wireless sensor and the power transmission timing, and determines the on / off logic of the power supply circuit.

3. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, The specific process for determining the switching control signal when a wireless sensor wakes up from sleep mode is as follows: Based on the node energy state characteristics of all wireless sensors, construct the energy state parameters of the wireless sensors when they are in sleep mode; The energy loss gradient during the current wake-up transition is determined by the energy state parameters and the energy conversion efficiency during the corresponding wireless sensor wake-up transition. The switching control signal for waking the wireless sensor from sleep mode is determined based on the energy loss gradient.

4. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, The specific process of obtaining the conduction control signal of the main power switch of the wireless sensor before conduction by modulating the power supply control signal and the conversion control signal according to the power supply balance requirements of the wireless sensor is as follows: Based on the power balance requirements of wireless sensors and the current load power consumption of wireless sensors, power balance characteristic parameters are constructed. Phase matching is performed on the power supply control signal and the conversion control signal based on the power supply balance characteristic parameters to obtain the power supply balance modulation coefficient; The conversion control signal is pulse-width modulated by the power supply balance modulation coefficient to generate a pre-conduction reference signal before conduction. By performing a logical AND operation between the pre-conduction reference signal and the power supply control signal, the conduction control signal of the main power switch of the wireless sensor before conduction is obtained.

5. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, The specific process for determining the conduction triggering rule of the main power switch when it is turned on is as follows: Based on the timing characteristics of the main power switch voltage dropping to zero voltage point, a zero voltage point state vector is constructed. The conduction time window of the main power switch after the zero voltage point is determined by the zero voltage point state vector and the current resonant period parameter. From the conduction time window, determine the conduction triggering rule of the main power switch when it is turned on.

6. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, The specific process for adjusting the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule is as follows: Based on the conduction triggering rules and the current switching cycle parameters of the main power switch, a voltage compensation feature vector within the cycle is constructed. The amount of compensation voltage adjustment is determined by the voltage compensation eigenvector within the cycle and the energy transfer efficiency of the resonant converter. Extract the compensation voltage limit of the main power switch during the switching cycle from the compensation voltage adjustment.

7. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, Based on the conduction control signal of the main power switch before conduction of the wireless sensor and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, the specific process of determining the switching feedback amplitude of the main power switch after it completes zero voltage turn-on is as follows: Based on the conduction control signal of the main power switch before conduction and the conduction voltage threshold of the main power switch when it is turned on at zero voltage, the initial conduction state vector of the main power switch after zero voltage is extracted. Based on the initial conduction state vector and the energy transfer characteristics of the resonant converter, the feedback adjustment coefficient after zero-voltage turn-on is determined. The preset reference feedback amplitude is dynamically corrected by the feedback adjustment coefficient to generate the switching feedback amplitude after the main power switch completes zero-voltage turn-on.

8. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, The turn-on voltage threshold refers to the critical voltage criterion for the main power switch to achieve zero-voltage turn-on. Only when the drain-source voltage of the main power switch is lower than the turn-on voltage threshold is the output turn-on trigger signal allowed.

9. The AC-DC conversion method for wireless sensors based on zero-voltage switching according to claim 1, characterized in that, The conduction control signal refers to the signal that controls the conduction timing, conduction pulse width, and initial conduction amplitude of the main power switch.

10. A wireless sensor AC-DC conversion system based on zero-voltage switching, used to perform a wireless sensor AC-DC conversion method based on zero-voltage switching as described in any one of claims 1 to 9, characterized in that, The conversion system includes: The acquisition module is used to acquire the power supply control signal of the wireless sensor when the power transmission is cut off when the wireless sensor enters sleep mode. The modulation module is used to determine the switching control signal when the wireless sensor wakes up from the sleep mode. It modulates the power supply control signal and the switching control signal according to the power supply balance requirements of the wireless sensor to obtain the conduction control signal of the main power switch of the wireless sensor before it is turned on. The processing module is used to determine the conduction triggering rule of the main power switch when the voltage of the main power switch drops to zero voltage point, adjust the compensation voltage limit of the main power switch during the switching cycle according to the conduction triggering rule, and then determine the conduction voltage threshold of the main power switch when it is turned on at zero voltage based on the compensation voltage limit. The execution module is used to determine the switching feedback amplitude of the main power switch after it completes zero-voltage turn-on, based on the conduction control signal of the main power switch before it is turned on and the conduction voltage threshold of the main power switch when it is turned on at zero voltage. The DC operating voltage of the wireless sensor is gradually restored through the switching feedback amplitude.

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