AC source accuracy compensation method and system with high load regulation

Abstract

This invention provides a method and system for AC source accuracy compensation with high load regulation. The method includes: real-time acquisition of signals from the AC source output terminal; denoising and synchronous calibration of the acquired signals to obtain a preprocessed signal; load condition prediction based on the preprocessed load current signal; adaptive adjustment of PIR controller parameters based on the load condition prediction result, using the PIR controller to correct the output voltage reference value to obtain a corrected voltage reference signal; using the corrected voltage reference signal as the setpoint for the voltage outer loop and the inverter output inductor current as the feedback for the current inner loop, executing voltage and current dual closed-loop control to generate a modulation reference signal; and generating corresponding switching pulse signals based on the modulation reference signal to drive the inverter output. This invention significantly improves the output voltage accuracy, dynamic response capability, and steady-state stability of the AC source over a wide load range through load condition prediction and adaptive PIR reference correction.

Description

Technical Field

[0001] This invention relates to the field of power electronic power supply control technology, and in particular to a method, system, electronic device, and computer-readable storage medium for AC source accuracy compensation with high load regulation. Background Technology

[0002] With the rapid development of industries such as power electronics equipment, new energy grid connection testing, and testing instruments, AC power sources, as key power supply devices providing high-quality AC power to devices under test (DUTs) or systems under test, are receiving increasing attention for their output accuracy and load adaptability. Load regulation is one of the core indicators for evaluating AC power source performance, reflecting its ability to maintain stable output voltage under different load conditions. Improving load regulation is crucial for expanding the applicability of power supplies and enhancing the reliability of test results for DUTs.

[0003] Currently, the mainstream technologies for improving AC power supply load regulation in the industry mainly fall into two categories. The first is hardware circuit-level improvements, which reduce output impedance by lowering line impedance and using low-on-resistance switching transistors, thereby suppressing voltage drops caused by load changes. This method is simple and direct to implement and does not significantly affect the stability of the control loop. However, its improvement effect is limited by device performance and topology, and it significantly increases system cost and size, making it difficult to meet the development needs of miniaturized and low-cost power supplies. The second is software control-level improvements, which accelerate dynamic response and reduce steady-state error by increasing the loop gain of voltage and current closed-loop control. However, the increase in loop gain is limited by stability margin; excessively high loop gain can easily cause system oscillation or even instability, making it difficult to simultaneously achieve steady-state accuracy and dynamic stability.

[0004] Therefore, a new solution is needed. Summary of the Invention

[0005] The purpose of this invention is to provide a method, system, electronic device, and computer-readable storage medium for AC source accuracy compensation with high load regulation, in order to solve the defect of low output voltage accuracy of existing AC sources over a wide load range.

[0006] The technical problem solved by this invention is achieved by the following technical solution: A method for high load regulation AC source accuracy compensation includes the following steps: S1. Real-time acquisition of voltage signal, current signal and load impedance characteristic signal at the output of AC source; S2. Perform noise reduction and synchronization calibration on the acquired signal to obtain the preprocessed signal; S3. Based on the preprocessed load current signal, predict the load conditions, which include at least load change conditions and periodic load conditions. S4. Based on the load condition prediction result, adaptively adjust the parameters of the PIR controller, and use the PIR controller to correct the output voltage reference value to obtain the corrected voltage reference signal. S5. Using the corrected voltage reference signal as the given voltage outer loop and the inverter output inductor current as the feedback of the current inner loop, perform voltage and current dual closed-loop control to generate a modulation reference signal. S6. Generate a corresponding switching pulse signal based on the modulation reference signal to drive the inverter output.

[0007] According to the AC source accuracy compensation method with high load regulation provided by the present invention, the denoising and synchronization calibration process in step S2 specifically includes: using Kalman filtering to denoise the sampled signal, eliminating grid harmonic interference through notch filter, and then performing signal synchronization calibration.

[0008] According to the AC source accuracy compensation method with high load regulation provided by the present invention, the load condition prediction in step S3 specifically includes: When the absolute value of the load current change rate exceeds the preset threshold and shows a continuous upward or downward trend, the current load condition is predicted to be a load change condition, and the direction of the change is locked. When a periodic fluctuation in the load current rate of change is detected, the current load condition is predicted to be a periodic load condition. The load current signal is then subjected to spectrum analysis using a fast Fourier transform to pinpoint the fundamental frequency and main harmonic frequencies of the periodic disturbance.

[0009] According to the AC source accuracy compensation method with high load regulation provided by the present invention, in step S4, the adaptive adjustment of the PIR controller parameters specifically includes: Under the aforementioned periodic load condition, the center frequency of the quasi-resonant element in the PIR controller is determined based on the fundamental frequency locked by spectrum analysis, and the resonant gain is adjusted according to the magnitude of the error. Under the condition of sudden load change, the integral coefficient of the PIR controller is reduced and the proportional coefficient is increased, while the resonant gain is adjusted to a preset basic guaranteed value.

[0010] According to the AC source accuracy compensation method with high load regulation provided by the present invention, in step S4, the output voltage reference value is corrected using the PIR controller to obtain a corrected voltage reference signal that satisfies the following formula: .

[0011]

[0012] in, The corrected voltage reference signal is... The output voltage reference value is... The voltage signal is obtained after signal preprocessing. u cmt The reference voltage correction term obtained by the PIR controller. k p_cmt , k i_cmt and k r These are the proportional, integral, and resonant gain of the PIR controller, respectively. ω c This is the cutoff frequency of the resonant controller. ω 0 represents the center frequency of the resonant controller.

[0013] According to the AC source accuracy compensation method with high load regulation provided by the present invention, in step S5, the execution of voltage and current dual closed-loop control specifically includes: In the outer voltage loop, the difference between the corrected voltage reference signal and the inverter output voltage is subjected to PI control, and the control output is superimposed with the inverter output current feedforward and the virtual damping to obtain the inductor current reference value. In the inner current loop, the difference between the inductor current reference value and the inverter output inductor current is subjected to PI control, and the control output is superimposed with the feedforward amount of the corrected voltage reference signal to obtain the modulation reference signal.

[0014] A high load regulation AC source accuracy compensation system for implementing the method described above includes: The signal sampling unit is used to acquire the voltage signal, current signal, and load impedance characteristic signal at the output of the AC source in real time. The signal preprocessing unit is used to perform noise reduction and synchronization calibration on the acquired signal to obtain the preprocessed signal. The load condition prediction unit is used to predict the load condition based on the preprocessed load current signal. The load condition includes at least load change condition and periodic load condition. An adaptive PIR control unit is used to adaptively adjust the parameters of the PIR controller based on the load condition prediction result, and to use the PIR controller to correct the output voltage reference value to obtain a corrected voltage reference signal. A dual-loop control unit is used to perform voltage and current dual-loop control by using the corrected voltage reference signal as the input of the voltage outer loop and the inverter output inductor current as the feedback of the current inner loop, and to generate a modulation reference signal. The pulse modulation unit is used to generate a corresponding switching pulse signal based on the modulation reference signal to drive the inverter output.

[0015] According to the AC source accuracy compensation system with high load regulation provided by the present invention, the signal sampling unit, the signal preprocessing unit, the load condition prediction unit and the adaptive PIR control unit are arranged in a digital signal processor; the dual closed-loop control unit is arranged in a field programmable gate array.

[0016] An electronic device includes a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the steps of the AC source accuracy compensation method with high load regulation as described above.

[0017] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the AC source accuracy compensation method with high load regulation as described in any one of the preceding descriptions.

[0018] The technical effects achieved by the above-mentioned technical solution of the present invention are as follows: The AC source accuracy compensation method and system with high load regulation provided by the present invention significantly improves the output voltage accuracy, dynamic response capability and steady-state stability of the AC source over a wide load range by integrating multi-dimensional signal sampling, load condition prediction, adaptive PIR reference correction and voltage and current dual closed-loop control; the solution achieves a fast and targeted response to load changes without significantly increasing hardware costs or compromising the stability of the control loop, and significantly improves the load regulation of the AC source. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort: Figure 1 This is a block diagram of AC source accuracy compensation control provided by the present invention.

[0020] Figure 2 This is the AC source voltage loop control block diagram provided by the present invention.

[0021] Figure 3 This is the AC source current loop control block diagram provided by the present invention.

[0022] Figure 4 This is a flowchart illustrating the AC source accuracy compensation method with high load regulation provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the AC source accuracy compensation system with high load regulation rate provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0025] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the embodiments of the present invention. Through the description of the specific embodiments, a more in-depth and specific understanding of the technical means and effects adopted by the present invention to achieve its intended purpose can be obtained. Moreover, the accompanying drawings are only provided for reference and illustration and are not intended to limit the present invention.

[0026] Existing AC source control schemes have the following problems: output impedance compression at the hardware level has cost and size limits; loop gain improvement at the pure software level is prone to oscillation; fixed parameter controllers have poor adaptability to various loads such as resistive, inductive, capacitive, and rectifier; there is a lack of differentiated processing mechanisms for sudden and periodic disturbances; and it is impossible to achieve smooth parameter switching between dynamic and steady-state processes.

[0027] To address the aforementioned problems, this invention proposes a high-load-regulation AC source accuracy compensation method. This method first involves real-time acquisition of the voltage, current, and load impedance characteristic signals at the AC source output. Then, the acquired signals undergo denoising and synchronization calibration to obtain a pre-processed signal. Next, load condition prediction is performed based on the pre-processed load current signal, identifying at least sudden load changes and periodic load conditions. Then, based on the load condition prediction results, the parameters of the PIR controller are adaptively adjusted, and the PIR controller is used to correct the output voltage reference value, obtaining a corrected voltage reference signal. Finally, the corrected voltage reference signal is used as the voltage outer loop setpoint, and the inverter output inductor current is used as the current inner loop feedback to execute dual closed-loop voltage and current control, generating a modulation reference signal. Based on this modulation reference signal, a corresponding switching pulse signal is generated to drive the inverter output.

[0028] The method provided in this invention firstly extracts reliable load characteristic information from noisy and harmonic-containing actual operating condition signals based on multi-dimensional signal sampling and preprocessing, providing high-quality input for subsequent operating condition prediction. Secondly, it distinguishes between abrupt and periodic disturbances through a load operating condition prediction mechanism, and adaptively adjusts the proportional, integral, and resonant parameters of the PIR controller accordingly, ensuring the controller always operates in the most suitable state for the current operating condition. Thirdly, by introducing a PIR reference correction stage, the output voltage reference is pre-corrected before the dual-loop control, effectively adding an independent accuracy compensation channel outside the original control loop, thereby improving steady-state accuracy without compromising inner-loop stability. Finally, the voltage and current dual-loop control, supplemented by current feedforward and virtual damping control, further accelerates the dynamic response.

[0029] In summary, the method provided in this invention significantly improves the output accuracy, load regulation, and dynamic stability of the AC source by integrating load condition prediction, adaptive PIR reference correction, and dual closed-loop control of voltage and current with feedforward and virtual damping. This solution achieves a rapid and targeted response to load changes without significantly increasing hardware costs or compromising control loop stability.

[0030] This invention can be applied to scenarios requiring high-precision AC output, such as relay protection test sources, new energy grid connection simulation sources, power metering verification sources, and AC voltage regulators. The execution entity of this method can be an electronic device such as a DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), microcontroller, or industrial control computer, or it can be an AC source accuracy compensation device installed in such an electronic device. This device can be implemented through software, hardware, or a combination of both.

[0031] In the description of the embodiments of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0032] Figure 4 This is one of the flowcharts illustrating the AC source accuracy compensation method with high load regulation provided by the present invention, such as... Figure 4 As shown, the method includes the following steps S1 to S6.

[0033] Step S1: Real-time acquisition of voltage signal, current signal and load impedance characteristic signal at the output terminal of AC source.

[0034] Specifically, this step uses a multi-dimensional signal sampling unit to acquire key status information of the output terminal during the operation of the AC source in real time, providing raw input for subsequent noise reduction, operating condition prediction, and control. The multi-dimensional signal sampling unit includes a high-speed synchronous ADC chip, a voltage sensor, a current sensor, and a load impedance detection module.

[0035] Voltage signals are acquired from the inverter output port through isolated voltage sensors (such as voltage sensors based on the Hall effect or operational amplifier isolation), reflecting the instantaneous voltage output by the AC source under test; current signals are acquired from the inverter output inductor branch and the load access branch through current sensors, obtaining the inductor current and load current respectively; the load impedance characteristic signal is calculated online by the load impedance detection module based on the acquired instantaneous voltage and current values, thus providing a basis for identifying the characteristics of resistive, inductive, capacitive, nonlinear, and other loads.

[0036] High-speed synchronous ADC chips sample the aforementioned analog signals synchronously under a unified sampling clock, avoiding false phase errors introduced due to asynchronous sampling times.

[0037] Step S2: Denoise and synchronize the acquired signal to obtain the preprocessed signal.

[0038] Specifically, this step processes the original sampled signal through a signal preprocessing unit, which includes a Kalman filter module, a notch filter module, and a signal synchronization calibration module.

[0039] In some possible implementations, step S2 specifically includes: using Kalman filtering to denoise the sampled signal, eliminating power grid harmonic interference through a notch filter, and then performing signal synchronization calibration.

[0040] The Kalman filter module performs optimal estimation of the noisy sampling sequence based on the state-space model of the voltage and current signals, effectively suppressing high-frequency electromagnetic interference while preserving the dynamic characteristics of the signal. The notch filter module sets the center frequency for the power frequency and typical power grid harmonic frequencies (such as the 50Hz fundamental frequency and its odd harmonics) to perform narrowband suppression of coupling interference from the power grid, preventing external harmonics from entering the control loop and causing misjudgments. The signal synchronization calibration module applies phase compensation and time delay alignment to signals from different sensor channels, so that the signals after passing through the filtering link are re-aligned in phase, ensuring that the voltage and current signals used in subsequent control operations are strictly synchronized.

[0041] The preprocessed signals obtained after the above processing include the preprocessed output voltage, the preprocessed output current, the preprocessed inductor current, and the preprocessed load impedance characteristic signal.

[0042] Step S3: Based on the preprocessed load current signal, predict the load condition. The load condition includes at least the load change condition and the periodic load condition.

[0043] Specifically, this step analyzes the time and frequency domain characteristics of the load current using a load condition prediction unit to identify the current load condition type, providing a basis for subsequent adaptive adjustment of controller parameters. The load condition prediction unit incorporates an FFT spectrum analysis module and a load type identification module.

[0044] In some possible implementations, step S3 specifically includes: Step S31: Calculate the rate of change per unit time for the preprocessed load current signal; Step S32: When the absolute value of the rate of change exceeds the preset threshold for several consecutive sampling periods and the sign remains consistent (i.e., continuously rising or continuously falling), the current load condition is predicted to be a load change condition, and the direction of the change is locked as "load increase" or "load decrease" according to the sign of the rate of change. Step S33: When the rate of change is detected to fluctuate periodically (i.e., the zero-crossing points of the rate of change appear at equal intervals), the current load condition is predicted to be a periodic load condition. The load current signal is then analyzed by Fast Fourier Transform (FFT) to lock the fundamental frequency and main harmonic frequency of the periodic disturbance.

[0045] The preset threshold here can be set according to the rated output current of the AC source. For example, when the rated output current of the AC source is 10A, the preset threshold can be 0.5A / ms or 1A / ms; when the maximum peak amplitude of the FFT spectrum analysis result other than the power frequency component accounts for more than the preset proportion (e.g., 10%) of the total energy, it is considered that there is a significant periodic disturbance.

[0046] By distinguishing between abrupt and periodic disturbances, this step lays the foundation for subsequent differentiated adjustment of controller parameters: abrupt disturbances mainly affect the dynamic process, requiring an increase in proportional gain and suppression of integral saturation; periodic disturbances mainly affect the steady-state process, requiring the resonant circuit to be accurately aligned with the disturbance frequency to achieve narrowband high-gain suppression.

[0047] Step S4: Based on the load condition prediction result, the parameters of the PIR controller are adaptively adjusted, and the output voltage reference value is corrected using the PIR controller to obtain the corrected voltage reference signal.

[0048] Specifically, this step is implemented in the DSP through an adaptive PIR control unit, which integrates a PIR controller, a parameter adaptive adjustment module, and a smooth transition module. As the core control unit for accuracy compensation, its output, as the compensation amount, together with the output voltage reference feedforward, serves as the voltage reference for the voltage and current dual closed-loop control in the subsequent FPGA.

[0049] In some possible implementations, adaptive adjustment of the PIR controller parameters specifically includes: Step S41: Under the periodic load condition, the center frequency ω0=2πf0 of the quasi-resonant element in the PIR controller is determined based on the fundamental frequency f0 locked by spectrum analysis, so that the resonant element is accurately aligned with the disturbance frequency; at the same time, the resonant gain k is adjusted according to the root mean square value of the current error. r —The larger the error, the higher the resonant gain, but its upper limit is limited to the stable boundary that does not induce loop oscillation; Step S42, under the load change condition, activate the parameter priority adjustment mechanism: temporarily reduce the integral coefficient k. i_cmt To avoid overshoot caused by integral saturation, the proportional coefficient k is significantly increased. p_cmt To improve dynamic response speed and increase resonant gain k r Adjust to a preset baseline protection value (e.g., 30% to 50% of the value under steady-state conditions) to ensure the accuracy of reference signal compensation during dynamic processes, while avoiding excessive interference from the resonant circuit during dynamic processes. Step S43: When switching operating conditions, the parameters of the PIR controller are smoothly switched using a first-order low-pass function through the smooth transition module to avoid transient impact on the control output caused by step changes in parameters.

[0050] The PIR controller is used to correct the output voltage reference value, resulting in a corrected voltage reference signal that satisfies the following formula: .

[0051]

[0052] in, The corrected voltage reference signal is the input voltage reference of the voltage loop in the subsequent dual closed-loop control. This refers to the output voltage reference value, i.e., the voltage reference at the relay. The voltage signal is obtained after signal preprocessing. u cmt The reference voltage correction term obtained by the PIR controller. k p_cmt , k i_cmt and kr These are the proportional, integral, and resonant gain of the PIR controller, respectively. ω c This is the cutoff frequency of the resonant controller, used to determine the bandwidth of the resonant circuit. ω 0 is the center frequency of the resonant controller, which corresponds to the fundamental angular frequency of the disturbance.

[0053] like Figure 1 As shown, the adaptive PIR control unit receives the pre-processed output voltage u from the relay. relay With reference to the target The error between the two is calculated and input into the PIR controller to obtain the reference voltage correction term. u cmt Then u cmt and By superimposing the signals, the corrected voltage reference signal is obtained. It is used as the voltage loop input reference for the subsequent dual closed-loop control.

[0054] This embodiment achieves accuracy compensation through a reference pre-correction method, which has the following advantages compared to directly adjusting the inner loop controller parameters: the reference correction stage is independent of the inner loop controller, and its adjustment will not affect the loop gain and phase margin of the inner loop, thus not compromising the stability of the original control system; by correcting the reference, steady-state accuracy can be improved without increasing the inner loop gain, avoiding the oscillation risk caused by high gain; the adaptive PIR controller has narrow-band high-gain suppression capability for periodic disturbances, and has stronger steady-state suppression capability in scenarios with rectifier loads, motor loads, etc., compared to traditional PI controllers.

[0055] Step S5: Using the corrected voltage reference signal as the given voltage outer loop and the inverter output inductor current as the feedback of the current inner loop, voltage and current dual closed-loop control is executed to generate a modulation reference signal.

[0056] Specifically, this step is implemented in the FPGA through a dual closed-loop control unit, consisting of an outer voltage loop and an inner current loop.

[0057] In some possible implementations, step S5 specifically includes: Step S51, in the voltage outer loop, the corrected voltage reference signal... With inverter output voltage u o The difference is used for PI control, and the control output is compared with the inverter output current i. o The inductor current reference value i is obtained by superimposing the feedforward quantity and the virtual damping quantity. L *, satisfying the following formula:

[0058] Among them, i L *Reference for inverter output inductor current, k pu and k iu For the proportional and integral coefficients of the voltage loop PI controller, u o i is the inverter output voltage. o R is the inverter output current. d This is a virtual resistor.

[0059] Step S52, in the inner current loop, the inductor current reference value i L * and inverter output inductor current i L The difference is used for PI control, and the control output is compared with the corrected voltage reference signal. The feedforward quantities are superimposed to obtain the modulation reference signal u*, which satisfies the following formula:

[0060] Where, k pi and k ii i represents the proportional and integral coefficients of the current loop PI controller. L This is the output inductor current of the inverter.

[0061] like Figure 2 and Figure 3 As shown, the outer voltage loop is responsible for tracking the corrected voltage reference. The inner current loop is responsible for quickly tracking the inductor current reference i. L Introducing output current feedforward into the outer voltage loop can accelerate the voltage loop's response to load disturbances; introducing virtual damping into the outer voltage loop... u o / R d This can improve system damping without increasing actual losses, suppress LC filter resonance, and prevent current overshoot. A voltage reference feedforward is introduced into the inner current loop. This can reduce the steady-state burden on the current loop PI controller, allowing the PI controller to primarily undertake error compensation tasks, thereby further improving tracking accuracy.

[0062] Step S6: Generate a corresponding switching pulse signal based on the modulation reference signal to drive the inverter output.

[0063] Specifically, this step is implemented through a pulse modulation unit, which compares the modulation reference signal u* with the triangular carrier signal and generates a pulse sequence to drive each switch of the inverter using methods such as sinusoidal pulse width modulation (SPWM) or space vector pulse width modulation (SVPWM). The generated switching pulse signal is amplified by the drive isolation circuit and then sent to the gate of the inverter power switch to control the on / off state of the switch, thereby making the voltage at the inverter output follow the corrected voltage reference signal.

[0064] Based on the above embodiments, the entire AC source accuracy compensation process constitutes a complete closed loop: signal sampling, signal preprocessing, load condition prediction, adaptive PIR reference correction, voltage and current dual closed loop, pulse modulation, inverter output, and feedback sampling. The adaptive PIR reference correction stage and the voltage and current dual closed loop stage are independent yet complementary: the former is responsible for externally compensating for the reference accuracy, enabling the inner loop to track a more accurate target; the latter is responsible for internally performing high-dynamic tracking of the reference, ensuring both the speed of transient processes and the accuracy of steady-state processes.

[0065] In some alternative solutions, the adaptive PIR control unit can be integrated with the dual closed-loop control unit in the same FPGA, or entirely implemented by a DSP; in addition to FFT spectrum analysis, the load condition prediction mechanism can also employ time-frequency analysis methods such as wavelet transform and Hilbert-Huang transform; load type identification can be achieved by combining multiple characteristics such as voltage-current phase difference and harmonic content, in addition to impedance characteristic identification; virtual damping control can also be constructed from active damping terms into a higher-order form to adapt to different LC filter parameters. Those skilled in the art, guided by the present invention, can implement the above equivalent transformations, all of which fall within the scope of protection of this invention.

[0066] In summary, the method provided in this invention achieves the following core breakthroughs compared to existing technologies through multi-dimensional signal sampling, load condition prediction, adaptive PIR reference correction, and a collaborative design of voltage and current dual closed loops including feedforward and virtual damping: 1. Significantly improved output accuracy over a wide load range: Through the adaptive PIR reference correction circuit, the steady-state error of the output voltage under different load conditions is significantly reduced, and the load regulation rate is significantly improved compared with the traditional dual closed-loop control. 2. Enhanced dynamic response capability and effective overshoot suppression: Under sudden load changes, the dynamic response speed is accelerated and the overshoot caused by integral saturation is suppressed by adaptively increasing the proportional gain and decreasing the integral gain; at the same time, the current surge caused by LC filter resonance is suppressed by virtual damping and output current feedforward. 3. Strong ability to suppress periodic disturbances: Under periodic load conditions, the PIR controller can accurately align with the disturbance frequency and provide high gain suppression through FFT frequency locking and adaptive resonant gain, which significantly reduces the harmonic content of the output voltage. 4. No significant increase in hardware cost or disruption of loop stability: The reference correction stage is independent of the inner loop controller, and its adjustment does not affect the loop gain and phase margin of the inner loop; the collaborative division of labor between the DSP and FPGA fully leverages the computational characteristics of both, improving the real-time performance and scalability of the system.

[0067] The following describes the AC source accuracy compensation system with high load regulation rate provided by the present invention. The system described below and the method described above can be referred to in correspondence.

[0068] Figure 5 This is a schematic diagram of the AC source accuracy compensation system with high load regulation rate provided by the present invention, as shown below. Figure 5 As shown, the system includes: The signal sampling unit 510 is used to acquire the voltage signal, current signal and load impedance characteristic signal at the output of the AC source in real time. The signal preprocessing unit 520 is used to perform noise reduction and synchronization calibration on the acquired signal to obtain the preprocessed signal. The load condition prediction unit 530 is used to predict the load condition based on the preprocessed load current signal. The load condition includes at least load change condition and periodic load condition. The adaptive PIR control unit 540 is used to adaptively adjust the parameters of the PIR controller according to the load condition prediction result, and use the PIR controller to correct the output voltage reference value to obtain the corrected voltage reference signal. The dual closed-loop control unit 550 is used to perform voltage and current dual closed-loop control by using the modified voltage reference signal as the input of the voltage outer loop and the inverter output inductor current as the feedback of the current inner loop, and to generate a modulation reference signal. The pulse modulation unit 560 is used to generate a corresponding switching pulse signal according to the modulation reference signal to drive the inverter output.

[0069] Based on the above embodiments, the signal sampling unit, the signal preprocessing unit, the load condition prediction unit, and the adaptive PIR control unit are arranged in a digital signal processor (DSP); the dual closed-loop control unit is arranged in a field-programmable gate array (FPGA). This division of labor fully utilizes the advantages of DSP in floating-point operations and complex algorithms (such as Kalman filtering, FFT, and adaptive parameter adjustment), as well as the advantages of FPGA in parallel operations, high-speed logic, and low-latency control, thereby constructing a high-performance AC source control platform that can perform complex preprocessing and achieve high-speed closed-loop control.

[0070] Based on the above embodiments, the signal preprocessing unit is specifically used to: perform noise reduction processing on the sampled signal using Kalman filtering, eliminate power grid harmonic interference using notch filter, and then perform signal synchronization calibration.

[0071] Based on the above embodiments, the load condition prediction unit is specifically used to: when the absolute value of the load current change rate exceeds a preset threshold and shows a continuous upward or downward trend, predict that the current load condition is a load change condition and lock the direction of the change; when the load current change rate shows periodic fluctuations, predict that the current load condition is a periodic load condition, and perform spectrum analysis on the load current signal through fast Fourier transform to lock the fundamental frequency and main harmonic frequency of the periodic disturbance.

[0072] Based on the above embodiments, the adaptive PIR control unit is specifically used to: determine the center frequency of the quasi-resonant element in the PIR controller according to the fundamental frequency locked by spectrum analysis under the periodic load condition, and adjust the resonant gain according to the magnitude of the error; under the load change condition, decrease the integral coefficient of the PIR controller and increase the proportional coefficient, while adjusting the resonant gain to a preset basic guarantee value.

[0073] Based on the above embodiments, the dual closed-loop control unit is specifically used for: in the voltage outer loop, performing PI control on the difference between the corrected voltage reference signal and the inverter output voltage, and superimposing the control output with the inverter output current feedforward and the virtual damping to obtain the inductor current reference value; in the current inner loop, performing PI control on the difference between the inductor current reference value and the inverter output inductor current, and superimposing the control output with the corrected voltage reference signal feedforward to obtain the modulation reference signal.

[0074] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6As shown, the electronic device may include a processor 610, a communications interface 620, a memory 630, and a communication bus 640, wherein the processor 610, the communications interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call logic instructions in the memory 630 to execute a high-load regulation rate AC source accuracy compensation method, which includes the steps S1 to S6 described above.

[0075] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] On the other hand, the present invention also provides a computer program product, the computer program product including a computer program that can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer is able to execute the AC source accuracy compensation method with high load regulation rate provided by the above methods.

[0077] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the AC source accuracy compensation method with high load regulation provided by the methods described above.

[0078] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0079] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An AC source accuracy compensation method with high load regulation, characterized in that, Includes the following steps: S1. Real-time acquisition of voltage signal, current signal and load impedance characteristic signal at the output of AC source; S2. Perform noise reduction and synchronization calibration on the acquired signal to obtain the preprocessed signal; S3. Based on the preprocessed load current signal, predict the load condition. The load condition includes at least load change condition and periodic load condition. Specifically, the load condition prediction includes: when the absolute value of the load current change rate exceeds a preset threshold and shows a continuous upward or downward trend, predict the current load condition as a load change condition and lock the direction of the change; when the load current change rate shows periodic fluctuations, predict the current load condition as a periodic load condition, and perform spectrum analysis on the load current signal through fast Fourier transform to lock the fundamental frequency and main harmonic frequency of the periodic disturbance. S4. Based on the load condition prediction results, adaptively adjust the parameters of the PIR controller, and use the PIR controller to correct the output voltage reference value to obtain the corrected voltage reference signal. Specifically, the adaptive adjustment of the PIR controller parameters includes: under the periodic load condition, determining the center frequency of the quasi-resonant link in the PIR controller based on the fundamental frequency locked by spectrum analysis, and adjusting the resonant gain according to the error magnitude; under the load change condition, decreasing the integral coefficient of the PIR controller and increasing the proportional coefficient, while adjusting the resonant gain to a preset basic guarantee value. S5. Using the corrected voltage reference signal as the given voltage outer loop and the inverter output inductor current as the feedback of the current inner loop, perform voltage and current dual closed-loop control to generate a modulation reference signal. S6. Generate a corresponding switching pulse signal based on the modulation reference signal to drive the inverter output.

2. The high load regulation AC source accuracy compensation method of claim 1, wherein, The denoising and synchronization calibration process in step S2 specifically includes: using Kalman filtering to denoise the sampled signal, eliminating power grid harmonic interference through a notch filter, and then performing signal synchronization calibration.

3. The high load regulation AC source accuracy compensation method of claim 1, wherein, In step S4, the PIR controller is used to correct the output voltage reference value to obtain a corrected voltage reference signal that satisfies the following formula: wherein, is the modified voltage reference signal, is the output voltage reference value, is the voltage signal after signal pre-processing, u cmt is the reference voltage correction term from the PIR controller, k p_cmt , k i_cmt and k r are the proportional, integral and resonant gains of the PIR controller, respectively, ω c is the cutoff frequency of the resonant controller, ω 0 is the center frequency of the resonant controller.

4. The AC source accuracy compensation method with high load regulation rate according to claim 1, characterized in that, In step S5, the execution of voltage and current dual closed-loop control specifically includes: In the outer voltage loop, the difference between the corrected voltage reference signal and the inverter output voltage is subjected to PI control, and the control output is superimposed with the inverter output current feedforward and the virtual damping to obtain the inductor current reference value. In the inner current loop, the difference between the inductor current reference value and the inverter output inductor current is subjected to PI control, and the control output is superimposed with the feedforward amount of the corrected voltage reference signal to obtain the modulation reference signal.

5. A high load regulation AC source accuracy compensation system, used to implement the method as described in any one of claims 1 to 4, characterized in that, include: The signal sampling unit is used to acquire the voltage signal, current signal, and load impedance characteristic signal at the output of the AC source in real time. The signal preprocessing unit is used to perform noise reduction and synchronization calibration on the acquired signal to obtain the preprocessed signal. The load condition prediction unit is used to predict the load condition based on the preprocessed load current signal. The load condition includes at least load change condition and periodic load condition. Specifically, the load condition prediction includes: when the absolute value of the load current change rate exceeds a preset threshold and shows a continuous upward or downward trend, the current load condition is predicted to be a load change condition, and the direction of the change is locked; when the load current change rate shows periodic fluctuations, the current load condition is predicted to be a periodic load condition, and the load current signal is subjected to spectrum analysis by fast Fourier transform to lock the fundamental frequency and main harmonic frequency of the periodic disturbance. An adaptive PIR control unit is used to adaptively adjust the parameters of the PIR controller based on the load condition prediction result. The PIR controller is used to correct the output voltage reference value to obtain a corrected voltage reference signal. Specifically, the adaptive adjustment of the PIR controller parameters includes: under the periodic load condition, determining the center frequency of the quasi-resonant element in the PIR controller based on the fundamental frequency locked by spectrum analysis, and adjusting the resonant gain according to the error magnitude; under the load change condition, decreasing the integral coefficient of the PIR controller and increasing the proportional coefficient, while adjusting the resonant gain to a preset basic guarantee value. A dual-loop control unit is used to perform voltage and current dual-loop control by using the corrected voltage reference signal as the input of the voltage outer loop and the inverter output inductor current as the feedback of the current inner loop, and to generate a modulation reference signal. The pulse modulation unit is used to generate a corresponding switching pulse signal based on the modulation reference signal to drive the inverter output.

6. The AC source accuracy compensation system with high load regulation rate according to claim 5, characterized in that, The signal sampling unit, the signal preprocessing unit, the load condition prediction unit, and the adaptive PIR control unit are arranged in the digital signal processor; The dual closed-loop control unit is arranged in a field-programmable gate array.

7. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the AC source accuracy compensation method with high load regulation as described in any one of claims 1 to 4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the AC source accuracy compensation method with high load regulation rate as described in any one of claims 1 to 4.

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