OBC soft switching control method and system based on phase detection and adaptive PID

Abstract

The invention discloses an OBC soft switching control method and system based on phase detection and adaptive PID. According to the invention, through the phase detection module, the phase difference between the voltage and the current of the input power supply is monitored in real time, and the operation time sequence and the frequency of the soft switching are dynamically adjusted. The phase detection ensures that the soft switching operation is carried out at the optimal moment, unnecessary energy waste is avoided, the overall efficiency of the system is remarkably improved, a self-adaptive PID control algorithm is introduced, PID parameters are automatically adjusted according to real-time data of the phase detection, and it is ensured that the system can quickly respond and stably operate under different working conditions. The self-adaptive PID controller effectively solves the problem that traditional PID control is poor in adaptability when facing different loads and input power supply fluctuations, and finer control and higher system stability are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicle charging control, and in particular relates to an OBC soft switch control method and system based on phase detection and adaptive PID. Background Art

[0002] With the increasing popularity of electric vehicles, OBCs play a key role in the vehicle charging process. An electric vehicle OBC (On-Board Charger) is a key component of an electric vehicle. Its primary function is to convert AC grid power into DC power suitable for charging the electric vehicle's power battery. Typically installed inside an electric vehicle, the OBC features intelligent charging control, automatically adjusting the charging current and voltage based on battery status and grid conditions to ensure charging efficiency and safety. The OBC's design fully considers charging speed, electromagnetic compatibility, heat dissipation, and anti-interference capabilities. It supports multiple charging modes, such as slow and fast charging, providing electric vehicle users with convenient and reliable charging solutions. It is a crucial technical support for promoting the popularization and development of electric vehicles.

[0003] However, existing OBC control methods mostly use hard switching technology. This means that the sudden changes in voltage and current during the on / off process of the switching element generate switching losses, increasing heat generation and reducing circuit efficiency. To reduce switching losses, soft switching technology has been introduced. However, existing soft switching control methods suffer from strong dependence on system parameters and poor dynamic response. In particular, they cannot achieve fast response and adaptive regulation when the grid voltage fluctuates or the load changes. Summary of the Invention

[0004] The purpose of the present invention is to provide an OBC soft switching control method and system based on phase detection and adaptive PID in order to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows: an OBC soft switching control method based on phase detection and adaptive PID, the method comprising the following steps: S1: Start the on-board charger (OBC) system, initialize the phase detection module, adaptive PID controller and signal acquisition device; configure the A / D converter and digital filter, collect the voltage and current signals of the input power supply in real time, and complete the initial calibration of the system parameters; S2: The collected voltage and current signals are filtered and de-noised by the phase detection module, and the phase difference θ(t) between them is calculated using a discrete Fourier transform (DFT) or phase-locked loop (PLL) algorithm. This generates a phase reference signal to provide a timing reference for soft switching operations. S3: Error calculation: compare the output voltage with the reference voltage in real time and calculate the error value; Dynamic adjustment of PID parameters: Based on the error e(t), the error integral term ∫e(τ)dτ and the error change rate de(t) / dt, the proportional (K_p), integral (K_i) and differential (K_d) gain parameters are dynamically adjusted through adaptive functions f1, f2 and f3 to adapt to load changes and input fluctuations; S4: Calculate the optimal switching time by combining the phase difference θ(t) output by the phase detection module and the adjustment signal u(t) generated by the adaptive PID control algorithm controller; perform soft switching operation under zero voltage or zero current conditions to control the power device to turn on / off and minimize switching losses; S5: Monitor the output voltage, current, and soft switching effect in real time through the feedback loop, and input the results into the adaptive PID controller; dynamically compensate the PID parameters according to the sudden load change or input fluctuation, optimize the control strategy, suppress overshoot and oscillation, and ensure steady-state accuracy.

[0006] Preferably, in step S3, error calculation: the error e(t) of the system is calculated in real time, that is, the difference between the given value and the feedback value.

[0007] ; in, Desired output voltage, is the currently measured output voltage.

[0008] During the control process, the system collects the output voltage signal, Vmeasured(t), in real time and compares it with a predetermined reference voltage, Vreference(t). The difference, e(t), represents the system's current error—that is, the degree to which the system deviates from its ideal state. By continuously calculating this error, the controller can continuously track changes in the output voltage.

[0009] The error, e(t), is the input to the PID controller and directly reflects the current system deviation. By monitoring the error in real time, the controller can determine whether output adjustments are necessary to maintain a stable charging state.

[0010] The accuracy of error calculation directly affects the controller's response speed and stability. Accurate error calculation allows the system to respond quickly to output deviations, avoiding excessive voltage fluctuations and improving control accuracy.

[0011] Preferably, in step S4, the PID formula is: Calculate the output of the PID controller The basic equation of PID control is as follows: ; in: Represents the proportional gain, which is used to adjust the current error. Represents the integral gain, which eliminates the accumulated error. Represents the differential gain, which is used to predict the error change trend and reduce overshoot.

[0012] Part of the current error provides direct adjustment capabilities, proportional gain Determines the system's response speed to errors. If it is too large, the system will be too sensitive; otherwise, the response will be slow.

[0013] Integral control (I): The integral term is mainly used to solve the problem of steady-state error in the system.

[0014] Derivative control (D): The future trend is predicted based on the error change rate, which reduces the overshoot of the system and improves the dynamic response performance of the system.

[0015] Preferably, in step S3, adaptive adjustment is performed: according to the feedback error and error rate of change , the system dynamically adjusts 、 、 Parameters. The adaptive adjustment formula is as follows: ; ; ; in, 、 、 It is an adaptive adjustment function set according to the system status.

[0016] The control output changes the soft switching operation time and mode through the adjusted PID controller output signal to optimize the switching loss and efficiency during the charging process.

[0017] Where: Adaptive PID is defined by function 、 、 To dynamically adjust the proportional, integral and derivative gains.

[0018] The specific implementation can be carried out through the following steps: Feedback regulation: The controller adjusts the current error and error rate of change , the system dynamically adjusts 、 、 When the system error increases, the controller increases to speed up the response; when the error decreases, reduce To avoid overreaction.

[0019] Dynamic adaptation: Through the system's feedback data, it automatically adapts to different load conditions and external interference, and adjusts the system's controller parameters to ensure that the controller is always in the best state.

[0020] Preferably, in step S4, the algorithm of the phase detection module is used to monitor the phase difference between the input terminal voltage and current in real time to generate a switching reference signal. The specific steps are as follows: Voltage and current sampling: collecting voltage With current The signal is filtered to eliminate high-frequency noise.

[0021] Phase calculation: Calculate the phase difference between voltage and current signals using discrete Fourier transform (DFT) or phase-locked loop (PLL) methods The formula is: ; in, is the signed inverse tangent function, which is used to calculate the phase difference.

[0022] Phase reference generation: Based on the phase difference , generates a reference signal for the switching moment to ensure that the switching operation occurs at the appropriate phase point.

[0023] Preferably, in step S4, the specific control logic of the soft switch control is as follows: Switching moment calculation: combined with the phase deviation signal output by the phase detection module , and the output signal of the PID controller , determine the optimal switching moment.

[0024] Switching operation: At the switching moment, the power switching device is controlled to be turned on or off, ensuring that the switching operation occurs at a time when the voltage and current stress are small, thereby reducing switching losses.

[0025] Feedback and adjustment: After the switch operation, the voltage and current signals are obtained through the feedback loop and provided to the adaptive PID controller for further adjustment.

[0026] Phase difference calculation using function, which is based on the input current signal and voltage signals Calculate the relative phase difference between voltage and current In actual implementation, voltage and current signals are first sampled by sensors and converted to digital signals using an A / D converter. The system then processes the signals using a digital filter to remove noise and produce smoother voltage and current waveforms.

[0027] Phase difference The calculated results are used to determine the switching timing of the power switch. By monitoring the phase difference between voltage and current in real time, the system can ensure that the switching operation occurs at zero current or zero voltage, reducing switching losses and improving switching efficiency.

[0028] Reduced switching losses: By selecting the appropriate phase point for switching operations, the voltage and current stress on the switching devices can be effectively reduced, thereby reducing losses.

[0029] Improves system efficiency: Soft switching is performed at appropriate phase points, making the entire charging process more efficient and significantly reducing power loss.

[0030] Preferably, the OBC soft switching control system based on phase detection and adaptive PID is characterized in that the system includes: The system startup and initialization module is used to initialize the configuration of the phase detection module, the adaptive PID controller module and the signal acquisition and processing module when the system starts, set the initial parameters of the PID controller, and calibrate the signal acquisition device; The phase detection module is used to collect the voltage and current signals of the input power supply in real time, calculate the phase difference θ(t) between the two through the phase detection algorithm, and send the phase difference data to the adaptive PID controller module; The signal acquisition and processing module is used to convert the input analog voltage and current signals into digital signals through the A / D converter, eliminate noise interference by using filtering and denoising algorithms, and transmit the processed signals to the phase detection module; The adaptive PID controller module is used to receive the phase difference data and feedback signal from the phase detection module and the adaptive adjustment module, dynamically adjust the proportional gain (K_p), integral gain (K_i) and differential gain (K_d) parameters, generate the control signal u(t) and output it to the soft switch control module; The soft switching control module is used to adjust the switching frequency and operation timing according to the control signal u(t) output by the adaptive PID controller module, drive the power switch device to complete the soft switching operation under zero voltage or zero current conditions, and feed back the operation results to the feedback and adaptive adjustment module; Feedback and adaptive adjustment module, used to monitor the voltage and current signals output by the system in real time, evaluate the effect of soft switching operation, and feed the monitoring data back to the adaptive PID controller module to optimize the PID parameters; The input power fluctuation detection module is used to continuously detect the voltage and current fluctuations of the input power supply. When the fluctuation exceeds the preset threshold, the protection mechanism is triggered and an adjustment instruction is sent to the soft switch control module.

[0031] Preferably, the phase detection module and the signal acquisition and processing module are connected via a high-speed data bus to ensure synchronous acquisition and processing of voltage and current signals; the output end of the phase detection module is directly connected to the phase difference input port of the adaptive PID controller module.

[0032] Preferably, the soft switch control module includes a drive circuit and a switch logic controller, wherein: The driving circuit is used to convert the control signal u(t) into a high-precision PWM driving signal; The switching logic controller determines the optimal switching timing based on the phase difference θ(t) and the PWM signal.

[0033] Preferably, the feedback and adaptive adjustment module collects output terminal signals in real time through voltage sensors and current sensors, and uses a digital filtering algorithm to eliminate high-frequency interference, and then sends the processed data to the feedback input terminal of the adaptive PID controller module.

[0034] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In this invention, a phase detection module monitors the phase difference between the input power supply voltage and current in real time, dynamically adjusting the soft switching timing and frequency. Phase detection ensures that soft switching occurs at the optimal time, avoiding unnecessary energy waste and significantly improving overall system efficiency.

[0035] 2. This invention introduces an adaptive PID control algorithm that automatically adjusts PID parameters based on real-time phase detection data, ensuring rapid system response and stable operation under varying operating conditions. This adaptive PID controller effectively addresses the poor adaptability of traditional PID control to varying loads and input power fluctuations, achieving more refined control and greater system stability.

[0036] 3. This invention utilizes soft-switching control technology, combined with phase detection and an adaptive PID algorithm, to ensure that switching operations always occur under zero voltage or zero current conditions. The introduction of soft switching significantly reduces switching losses, improves overall system energy efficiency, extends the life of switching components, and resolves the high energy loss associated with traditional hard-switching operations.

[0037] 4. This invention incorporates a dynamic adjustment and real-time feedback mechanism to monitor the effects of switching operations in real time and automatically adjust PID control parameters based on this feedback, ensuring the system always operates optimally. This mechanism ensures that the system can quickly adjust and optimize control strategies in response to power fluctuations or load changes, improving system stability and security.

[0038] 5. This invention integrates multiple protection mechanisms, such as input power fluctuation monitoring, overvoltage protection, and overcurrent protection, ensuring that the system can respond promptly and take protective measures to prevent damage when the input power is unstable or abnormal. This multi-protection mechanism effectively improves the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is the overall flow chart of the system of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example

[0041] Reference Figure 1 , The OBC soft switching control method based on phase detection and adaptive PID includes the following steps: S1: Start the on-board charger (OBC) system, initialize the phase detection module, adaptive PID controller and signal acquisition device; configure the A / D converter and digital filter, collect the voltage and current signals of the input power supply in real time, and complete the initial calibration of the system parameters; S2: The collected voltage and current signals are filtered and de-noised by the phase detection module, and the phase difference θ(t) between them is calculated using a discrete Fourier transform (DFT) or phase-locked loop (PLL) algorithm. This generates a phase reference signal to provide a timing reference for soft switching operations. S3: Error calculation: compare the output voltage with the reference voltage in real time and calculate the error value e(t) = V_reference(t) - V_measured(t); Dynamic adjustment of PID parameters: Based on the error e(t), the error integral term ∫e(τ)dτ and the error change rate de(t) / dt, the proportional (K_p), integral (K_i) and differential (K_d) gain parameters are dynamically adjusted through adaptive functions f1, f2 and f3 to adapt to load changes and input fluctuations; S4: Calculate the optimal switching time by combining the phase difference θ(t) output by the phase detection module and the adjustment signal u(t) generated by the adaptive PID control algorithm controller; perform soft switching operation under zero voltage or zero current conditions to control the power device to turn on / off and minimize switching losses; S5: Monitor the output voltage, current, and soft switching effect in real time through the feedback loop, and input the results into the adaptive PID controller; dynamically compensate the PID parameters according to the sudden load change or input fluctuation, optimize the control strategy, suppress overshoot and oscillation, and ensure steady-state accuracy.

[0042] In step S3, error calculation: the system error e(t) is calculated in real time, that is, the difference between the given value and the feedback value.

[0043]

[0044] in, Desired output voltage, is the currently measured output voltage.

[0045] During the control process, the system collects the output voltage signal, Vmeasured(t), in real time and compares it with a predetermined reference voltage, Vreference(t). The difference, e(t), represents the system's current error—that is, the degree to which the system deviates from its ideal state. By continuously calculating this error, the controller can continuously track changes in the output voltage.

[0046] The error, e(t), is the input to the PID controller and directly reflects the current system deviation. By monitoring the error in real time, the controller can determine whether output adjustments are necessary to maintain a stable charging state.

[0047] The accuracy of error calculation directly affects the controller's response speed and stability. Accurate error calculation allows the system to respond quickly to output deviations, avoiding excessive voltage fluctuations and improving control accuracy.

[0048] In step S4, the PID formula is: Calculate the output of the PID controller The basic equation of PID control is as follows: ; in: Represents the proportional gain, which is used to adjust the current error. Represents the integral gain, which eliminates the accumulated error. Represents the differential gain, which is used to predict the error change trend and reduce overshoot.

[0049] Part of the current error provides direct adjustment capabilities, proportional gain Determines the system's response speed to errors. If it is too large, the system will be too sensitive; otherwise, the response will be slow.

[0050] Integral control (I): The integral term is mainly used to solve the problem of steady-state error in the system.

[0051] Derivative control (D): The future trend is predicted based on the error change rate, which reduces the overshoot of the system and improves the dynamic response performance of the system.

[0052] In step S3, adaptive adjustment: according to the feedback error and error rate of change , the system dynamically adjusts 、 、 Parameters. The adaptive adjustment formula is as follows: ; ; ; in, 、 、 It is an adaptive adjustment function set according to the system status.

[0053] The control output changes the soft switching operation time and mode through the adjusted PID controller output signal to optimize the switching loss and efficiency during the charging process.

[0054] Where: Adaptive PID is defined by function 、 、 To dynamically adjust the proportional, integral and derivative gains.

[0055] The specific implementation can be carried out through the following steps: Feedback regulation: The controller adjusts the current error and error rate of change , the system dynamically adjusts 、 、 When the system error increases, the controller increases to speed up the response; when the error decreases, reduce To avoid overreaction.

[0056] Dynamic adaptation: Through the system's feedback data, it automatically adapts to different load conditions and external interference, and adjusts the system's controller parameters to ensure that the controller is always in the best state.

[0057] In step S4, the algorithm of the phase detection module is used to monitor the phase difference between the input voltage and current in real time and generate a switching reference signal. The specific steps are as follows: Voltage and current sampling: collecting voltage With current The signal is filtered to eliminate high-frequency noise.

[0058] Phase calculation: Calculate the phase difference between voltage and current signals using discrete Fourier transform (DFT) or phase-locked loop (PLL) methods The formula is: ; in, is the signed inverse tangent function, which is used to calculate the phase difference.

[0059] Phase reference generation: Based on the phase difference , generates a reference signal for the switching moment to ensure that the switching operation occurs at the appropriate phase point.

[0060] In step S4, the specific control logic of the soft switch control is as follows: Switching moment calculation: combined with the phase deviation signal output by the phase detection module , and the output signal of the PID controller , determine the optimal switching moment.

[0061] Switching operation: At the switching moment, the power switching device is controlled to be turned on or off, ensuring that the switching operation occurs at a time when the voltage and current stress are small, thereby reducing switching losses.

[0062] Feedback and adjustment: After the switch operation, the voltage and current signals are obtained through the feedback loop and provided to the adaptive PID controller for further adjustment.

[0063] Phase difference calculation using function, which is based on the input current signal and voltage signals Calculate the relative phase difference between voltage and current In actual implementation, voltage and current signals are first sampled by sensors and converted to digital signals using an A / D converter. The system then processes the signals using a digital filter to remove noise and produce smoother voltage and current waveforms.

[0064] Phase difference The calculated results are used to determine the switching timing of the power switch. By monitoring the phase difference between voltage and current in real time, the system can ensure that the switching operation occurs at zero current or zero voltage, reducing switching losses and improving switching efficiency.

[0065] Reduced switching losses: By selecting the appropriate phase point for switching operations, the voltage and current stress on the switching devices can be effectively reduced, thereby reducing losses.

[0066] Improves system efficiency: Soft switching is performed at appropriate phase points, making the entire charging process more efficient and significantly reducing power loss.

[0067] The system includes: The system startup and initialization module is used to initialize the configuration of the phase detection module, the adaptive PID controller module and the signal acquisition and processing module when the system starts, set the initial parameters of the PID controller, and calibrate the signal acquisition device; The phase detection module is used to collect the voltage and current signals of the input power supply in real time, calculate the phase difference θ(t) between the two through the phase detection algorithm, and send the phase difference data to the adaptive PID controller module; The signal acquisition and processing module is used to convert the input analog voltage and current signals into digital signals through the A / D converter, eliminate noise interference by using filtering and denoising algorithms, and transmit the processed signals to the phase detection module; The adaptive PID controller module is used to receive the phase difference data and feedback signal from the phase detection module and the adaptive adjustment module, dynamically adjust the proportional gain (K_p), integral gain (K_i) and differential gain (K_d) parameters, generate the control signal u(t) and output it to the soft switch control module; The soft switching control module is used to adjust the switching frequency and operation timing according to the control signal u(t) output by the adaptive PID controller module, drive the power switch device to complete the soft switching operation under zero voltage or zero current conditions, and feed back the operation results to the feedback and adaptive adjustment module; Feedback and adaptive adjustment module, used to monitor the voltage and current signals output by the system in real time, evaluate the effect of soft switching operation, and feed the monitoring data back to the adaptive PID controller module to optimize the PID parameters; The input power fluctuation detection module is used to continuously detect the voltage and current fluctuations of the input power supply. When the fluctuation exceeds the preset threshold, the protection mechanism is triggered and an adjustment instruction is sent to the soft switch control module.

[0068] The phase detection module and the signal acquisition and processing module are connected via a high-speed data bus to ensure the synchronous acquisition and processing of voltage and current signals; the output end of the phase detection module is directly connected to the phase difference input port of the adaptive PID controller module.

[0069] The soft switch control module includes a drive circuit and a switch logic controller, wherein: The driving circuit is used to convert the control signal u(t) into a high-precision PWM driving signal; The switching logic controller determines the optimal switching timing based on the phase difference θ(t) and the PWM signal.

[0070] The feedback and adaptive adjustment module collects the output signal in real time through the voltage sensor and current sensor, and uses the digital filtering algorithm to eliminate high-frequency interference, and then sends the processed data to the feedback input of the adaptive PID controller module.

[0071] From the above we can know: In this invention, a phase detection module monitors the phase difference between the input power voltage and current in real time, dynamically adjusting the soft switching timing and frequency. Phase detection ensures that soft switching occurs at the optimal time, avoiding unnecessary energy waste and significantly improving overall system efficiency.

[0072] This invention introduces an adaptive PID control algorithm that automatically adjusts PID parameters based on real-time phase detection data, ensuring rapid system response and stable operation under varying operating conditions. This adaptive PID controller effectively addresses the poor adaptability of traditional PID control to varying loads and input power fluctuations, achieving more refined control and greater system stability.

[0073] In this invention, soft switching control technology, combined with phase detection and an adaptive PID algorithm, ensures that switching operations always occur under zero voltage or zero current conditions. The introduction of soft switching significantly reduces switching losses, improves overall system energy efficiency, extends the service life of switching components, and resolves the high energy loss problem associated with traditional hard switching.

[0074] This invention introduces a dynamic adjustment and real-time feedback mechanism to monitor the effects of switching operations in real time and automatically adjust PID control parameters based on this feedback, ensuring the system always operates optimally. This mechanism ensures that the system can quickly adjust and optimize control strategies in response to power fluctuations or load changes, improving system stability and security.

[0075] This invention integrates multiple protection mechanisms, such as input power fluctuation monitoring, overvoltage protection, and overcurrent protection, to ensure that the system can respond promptly and take protective measures to prevent damage when the input power is unstable or abnormal. This multi-protection mechanism effectively improves the safety and reliability of the system.

[0076] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An OBC soft switching control method based on phase detection and adaptive PID, characterized in that: Including steps: S1: Start the on-board charger system, initialize the phase detection module, adaptive PID controller and signal acquisition device; configure the A / D converter and digital filter, collect the voltage and current signals of the input power supply in real time, and complete the initial calibration of the system parameters; S2: The collected voltage and current signals are filtered and de-noised by the phase detection module, and the phase difference θ(t) between the two is calculated using a discrete Fourier transform or a phase-locked loop algorithm; Generate phase reference signal to provide timing reference for soft switching operation; S3: Error calculation: compare the output voltage with the reference voltage in real time and calculate the error value; Dynamic adjustment of PID parameters: Based on the error e(t), the error integral term ∫e(τ)dτ and the error change rate de(t) / dt, the proportional, integral and differential gain parameters are dynamically adjusted through the adaptive functions f1, f2 and f3 to adapt to load changes and input fluctuations; S4: Calculate the optimal switching time by combining the phase difference θ(t) output by the phase detection module and the adjustment signal u(t) generated by the adaptive PID control algorithm controller; perform soft switching operation under zero voltage or zero current conditions to control the power device to turn on / off and minimize switching losses; S5: Monitor the output voltage, current, and soft switching effect in real time through the feedback loop, and input the results into the adaptive PID controller; dynamically compensate the PID parameters according to the sudden load change or input fluctuation, optimize the control strategy, suppress overshoot and oscillation, and ensure steady-state accuracy.

2. The OBC soft switching control method based on phase detection and adaptive PID according to claim 1, characterized in that: In step S3, error calculation: real-time calculation of the system error e(t), i.e., the difference between the given value and the feedback value; ； in, Desired output voltage, is the currently measured output voltage; During the control process, the system collects the output voltage signal Vmeasured(t) in real time and compares it with a predetermined reference voltage Vreference(t). The difference e(t) represents the current system error, that is, the degree to which the system deviates from the ideal state. By continuously calculating this error, the controller can continuously track changes in the output voltage. The error e(t) is the input to the PID controller and directly reflects the current system deviation. By monitoring the error in real time, the controller can determine whether the output needs to be adjusted to maintain a stable charging state. The accuracy of error calculation directly affects the response speed and stability of the controller; through accurate error calculation, the system can respond quickly to output deviations, avoid excessive voltage fluctuations, and thus improve the control accuracy of the system.

3. The OBC soft switching control method based on phase detection and adaptive PID according to claim 1, characterized in that: In step S4, the PID formula is: ;The basic equation of PID control is as follows: ； in: Represents the proportional gain, which is used to adjust the current error. Indicates the integral gain, eliminating the cumulative error; Represents the differential gain, which is used to predict the error change trend and reduce overshoot; Part of the current error provides direct adjustment capabilities, proportional gain Determines the system's response speed to errors; if If it is too large, the system will be too sensitive; otherwise, the response will be slow; Integral control: The integral term can accumulate past errors, thereby eliminating long-term deviations; the integral term is mainly used to solve the problem of steady-state errors in the system; Derivative control: The future trend is predicted based on the error change rate, which reduces the overshoot of the system and improves the dynamic response performance of the system.

4. The OBC soft switching control method based on phase detection and adaptive PID according to claim 1, characterized in that: In step S3, adaptive adjustment is performed based on the feedback error. and error rate of change , the system dynamically adjusts 、 、 Parameters; the adaptive adjustment formula is as follows: ； ； ； in, 、 、 is an adaptive adjustment function set according to the system state; The control output changes the soft switching operation time and mode through the adjusted PID controller output signal to optimize the switching loss and efficiency during the charging process; Where: Adaptive PID is defined by function 、 、 To dynamically adjust the proportional, integral and derivative gains; The specific implementation can be carried out through the following steps: Feedback regulation: The controller adjusts the current error and error rate of change , the system dynamically adjusts 、 、 When the system error increases, the controller increases to speed up the response; when the error decreases, reduce To avoid overreaction; Dynamic adaptation: Through the system's feedback data, it automatically adapts to different load conditions and external interference, and adjusts the system's controller parameters to ensure that the controller is always in the best state.

5. The OBC soft switching control method based on phase detection and adaptive PID according to claim 1, characterized in that: In step S4, the algorithm of the phase detection module is used to monitor the phase difference between the input terminal voltage and current in real time to generate a switching reference signal; The specific steps are as follows: Voltage and current sampling: collecting voltage With current Signal, and filter the signal to eliminate high-frequency noise; Phase calculation: Calculate the phase difference between voltage and current signals using discrete Fourier transform or phase-locked loop methods ; The formula is: ； in, is the signed inverse tangent function, used to calculate the phase difference; Phase reference generation: Based on the phase difference , generates a reference signal for the switching moment to ensure that the switching operation occurs at the appropriate phase point.

6. The OBC soft switching control method based on phase detection and adaptive PID according to claim 1, characterized in that: In step S4, the specific control logic of the soft switch control is as follows: Switching moment calculation: combined with the phase deviation signal output by the phase detection module , and the output signal of the PID controller , determine the optimal switching moment; Switching operation: At the switching moment, the power switching device is controlled to be turned on or off, ensuring that the switching operation occurs at a time when the voltage and current stress are small, thereby reducing switching losses; Feedback and adjustment: After the switch is operated, the voltage and current signals are obtained through the feedback loop and provided to the adaptive PID controller for further adjustment; Phase difference calculation using function, which is based on the input current signal and voltage signals Calculate the relative phase difference between voltage and current In actual implementation, voltage and current signals are first sampled by sensors and converted into digital signals through A / D converters. The system then uses digital filters to process the signals, remove noise, and obtain smoother voltage and current waveforms. Phase difference The calculation results are used to determine the switching moment of the power switch; by real-time monitoring of the phase difference between voltage and current, the system can ensure that the switching operation occurs at zero current or zero voltage, reducing switching losses and improving switching efficiency; Reduced switching losses: By selecting the appropriate phase point for switching operations, the voltage and current stress on the switching devices can be effectively reduced, thereby reducing losses. Improved system efficiency: Soft switching operations are performed at appropriate phase points, making the entire charging process more efficient and significantly reducing power loss.

7. An OBC soft switching control system based on phase detection and adaptive PID, characterized by: The system comprises: The system startup and initialization module is used to initialize the configuration of the phase detection module, the adaptive PID controller module and the signal acquisition and processing module when the system starts, set the initial parameters of the PID controller, and calibrate the signal acquisition device; The phase detection module is used to collect the voltage and current signals of the input power supply in real time, calculate the phase difference θ(t) between the two through the phase detection algorithm, and send the phase difference data to the adaptive PID controller module; The signal acquisition and processing module is used to convert the input analog voltage and current signals into digital signals through the A / D converter, eliminate noise interference by using filtering and denoising algorithms, and transmit the processed signals to the phase detection module; The adaptive PID controller module is used to receive the phase difference data and feedback from the phase detection module and the feedback signal from the adaptive adjustment module, dynamically adjust the proportional gain, integral gain and differential gain parameters, generate a control signal u(t) and output it to the soft switch control module; The soft switching control module is used to adjust the switching frequency and operation timing according to the control signal u(t) output by the adaptive PID controller module, drive the power switch device to complete the soft switching operation under zero voltage or zero current conditions, and feed back the operation results to the feedback and adaptive adjustment module; Feedback and adaptive adjustment module, used to monitor the voltage and current signals output by the system in real time, evaluate the effect of soft switching operation, and feed the monitoring data back to the adaptive PID controller module to optimize the PID parameters; The input power fluctuation detection module is used to continuously detect the voltage and current fluctuations of the input power supply. When the fluctuation exceeds the preset threshold, the protection mechanism is triggered and an adjustment instruction is sent to the soft switch control module.

8. The OBC soft switching control system based on phase detection and adaptive PID according to claim 1, characterized in that: The phase detection module is connected to the signal acquisition and processing module via a high-speed data bus to ensure the synchronous acquisition and processing of voltage and current signals; the output end of the phase detection module is directly connected to the phase difference input port of the adaptive PID controller module.

9. The OBC soft switching control system based on phase detection and adaptive PID according to claim 1, characterized in that: The soft switch control module includes a drive circuit and a switch logic controller, wherein: The driving circuit is used to convert the control signal u(t) into a high-precision PWM driving signal; The switching logic controller determines the optimal switching timing based on the phase difference θ(t) and the PWM signal.

10. The OBC soft switching control system based on phase detection and adaptive PID according to claim 1, characterized in that: The feedback and adaptive adjustment module collects the output terminal signal in real time through the voltage sensor and the current sensor, and uses the digital filtering algorithm to eliminate high-frequency interference, and then sends the processed data to the feedback input terminal of the adaptive PID controller module.

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