Sampling signal compensation method of power converter and power conversion device

Abstract

The invention provides a sampling signal compensation method of a power supply converter and a power supply conversion device. The sampling signal compensation method comprises the following steps: S1, acquiring a sampling signal from the power supply converter; s2, obtaining the frequency of the sampling signal; s3, a compensation parameter calling index number is obtained through calculation according to the frequency of the sampling signal, a pre-stored compensation parameter table is inquired according to the compensation parameter calling index number, and a discrete compensation parameter table is obtained; s4, the sampling signal is compensated through the discrete compensation parameter table, a feedback signal is obtained, and the compensation parameter table is a discrete corresponding data table of time and compensation amount obtained at the lowest frequency of the sampled signal.

Description

Technical Field

[0001] The present application relates to the field of electronics, and in particular to a sampling signal compensation method for a power converter and a power converter device. Background Art

[0002] At present, with the development of new energy technology, more and more switching power supplies are being used in the field of life.

[0003] On the one hand, for the sake of people's quality of life and safety, higher requirements are placed on the reliability of the switching power supply itself, and therefore more stringent requirements are placed on the switching power supply's dynamic performance, ripple and other electrical properties; on the other hand, with the use of higher-power switching power supplies, the impact on the power grid is also becoming increasingly severe. In order to ensure the power supply quality and stability of the power grid, the harmonic content and reactive power brought by the switching power supply have also been designed with higher standards.

[0004] However, in the current design and development of switching power supplies, filtering circuits are added to the sampling circuits to improve the reliability and stability of the power supply. Due to the presence of filtering circuits, the sampling parameters obtained by the controller have certain errors in phase and amplitude compared to the actual electrical waveform. Using these erroneous sampling parameters as the control feedback parameters of the switching power supply further degrades the switching power supply's electrical performance, resulting in failure to meet industry specifications. Furthermore, the sampling circuits are affected differently in different operating environments, further leading to greater differences in sampling accuracy. As a result, the switching power supply's electrical performance, such as current harmonic content, power factor, dynamics, and ripple, under different operating environments, fails to meet industry specifications.

[0005] In addition, some existing sampling parameter compensation schemes have many limitations. On the one hand, sampling compensation only considers one working condition, resulting in the compensation scheme only being able to meet the optimization of the power supply electrical performance under a single working condition, and unable to adapt to the influence of multiple environments and conditions, that is, it is highly dependent on the line parameters of the switching power supply, resulting in poor robustness; on the other hand, it will introduce the calculation of loads such as trigonometric functions and root mean square calculations, occupying a large amount of computing resources of the microcontroller, and even forcing some controllers to replace higher-performance and more expensive controllers because they cannot meet the computing requirements, resulting in increased cost of the switching power supply. Summary of the Invention

[0006] According to one embodiment, the present application provides a sampling signal compensation method for a power converter, including: S1: obtaining a sampling signal from a power converter; S2: obtaining the frequency of the sampling signal; S3: calculating a compensation parameter call index number based on the frequency of the sampling signal, and querying a pre-stored compensation parameter table with the compensation parameter call index number to obtain a discrete compensation parameter table; S4: compensating the sampling signal with the discrete compensation parameter table to obtain a feedback signal, wherein the compensation parameter table is a discrete data table corresponding to time and compensation amount obtained at the lowest frequency of the sampled signal.

[0007] Furthermore, before step S1, the method further includes: step S0: obtaining the compensation parameter table, including: performing data analysis and processing based on the sampled signal and the actual signal at the lowest frequency of the sampled signal to obtain the compensation parameter table.

[0008] Furthermore, step S0 includes: S01: determining the frequency range [fmin, fmax] of the sampled signal, where fmin is the lowest frequency of the sampled signal and fmax is the highest frequency of the sampled signal; S02: detecting the sampling signal and the actual signal at the lowest frequency fmin of the sampled signal to obtain the sampling delay time ΔT of the sampling signal relative to the actual signal; S03: obtaining a sampling compensation parameter expression based on the sampling delay time ΔT; S04: selecting a time interval, calculating the number of samples N in the time interval according to the sampling period TAD of the sampling circuit, and discretizing the sampling compensation parameter expression with t=n*TAD, where n=1, 2, 3,…, N, to obtain a discrete compensation parameter table corresponding to time and compensation amount, where N is a natural number.

[0009] Furthermore, in S01, the temperature range [TEMP_MIN, TEMP_MAX] of the sampled signal is also determined, where TEMP_MIN is the lowest operating environment temperature of the sampled signal, and TEMP_MAX is the highest operating environment temperature of the sampled signal; in S02, the sampling delay time ΔT is also obtained at the lowest operating environment temperature TEMP_MIN of the sampled signal.

[0010] Furthermore, step S0 also includes: S05: fixing the amplitude and frequency of the sampled signal, adjusting the temperature within the range of [TEMP_MIN, TEMP_MAX] with the lowest temperature TEMP_MIN as the starting point and ΔTEMP as the step size, measuring the effective value of the sampled signal at each corresponding temperature, and obtaining a temperature compensation parameter curve corresponding to the temperature and temperature compensation parameter.

[0011] Furthermore, step S3 includes: S31: calculating the index number step size using the formula step = fr / fmin, where fr is the actual frequency of the sampling signal; S32: sampling time t = t + TAD; S33: determining whether the sampling signal crosses zero at the current sampling time t, if not, proceeding to step S34, if yes, proceeding to step S35; S34: setting the first index variable variable1 =

[0012] variable1+step, the second index variable variable2=variable1+0.5, round the second index variable to obtain the index number index; S36: determine whether the index number index is greater than or equal to N, if not, go to step S37, if so, go to step S38; S37: set the current index number index as the compensation parameter call index number, go to step S32; S38: set N as the compensation parameter call index number, end; S35: reset the index number index, the first index variable variable1 and the second index variable variable2, and go to step S32.

[0013] Furthermore, step S38 also includes S39: obtaining the current operating temperature; querying the temperature compensation parameter curve to obtain the temperature compensation coefficient corresponding to the current operating temperature; multiplying the discrete compensation parameter table in step S3 by the temperature compensation coefficient to obtain the discrete compensation parameter table in step S4.

[0014] Furthermore, step S38 also includes S39': obtaining the current operating temperature; querying the temperature compensation parameter curve to obtain the temperature compensation coefficient corresponding to the current operating temperature; step S4 is multiplying the compensation parameter obtained from the discrete compensation parameter table, the temperature compensation coefficient and the sampling signal to obtain the feedback signal.

[0015] The present application also provides a power conversion device, comprising: a power converter; a controller for controlling the power converter based on a sampling signal, wherein a compensation parameter table is stored in the controller, wherein the compensation parameter table is a discrete data table corresponding to time and compensation amount obtained at the lowest frequency of the sampled signal, wherein the controller executes the above-mentioned sampling signal compensation method of the power converter.

[0016] Furthermore, the power converter is an AC / AC converter, an AC / DC converter, a DC / DC converter or a DC / AC converter.

[0017] The features and technical advantages of the present disclosure have been summarized quite broadly above so that the detailed description disclosed below may be better understood. Additional features and advantages of the present disclosure will be described below, which form the subject matter of the claims of the present disclosure. It will be understood by those skilled in the art that the concepts and specific embodiments disclosed herein may be readily used as a basis for modifying or designing other structures or processes for achieving the same purposes of the present disclosure. It will also be appreciated by those skilled in the art that such equivalent structures do not depart from the spirit and scope of the present disclosure as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of a sampling signal compensation method for a power converter according to an embodiment of the present application is shown;

[0020] Figure 2 A schematic diagram of a sampling signal compensation method for a power converter according to another embodiment of the present application is shown;

[0021] Figure 3 A schematic diagram of a sampled voltage signal and an actual voltage signal according to an embodiment of the present application is shown;

[0022] Figure 4 A schematic diagram of a sampled voltage signal and an actual voltage signal according to another embodiment of the present application is shown;

[0023] Figure 5 The results obtained by an embodiment of the present application are shown in FIG. Figure 3 The waveform diagram of the compensation parameter k and the time t corresponding to the waveform shown;

[0024] Figure 6 The results obtained by an embodiment of the present application are shown in FIG. Figure 4 The waveform diagram of the compensation parameter k and the time t corresponding to the waveform shown;

[0025] Figure 7 A schematic diagram of a flow chart of obtaining a compensation parameter calling index number based on frequency calculation of a sampling signal according to an embodiment of the present application is shown.

[0026] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. These figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in this application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0028] For details, please refer to Figure 1 FIG. 1 is a schematic diagram of a sampling signal compensation method for a power converter according to an embodiment of the present application. The sampling signal compensation method for a power converter according to an embodiment of the present application includes:

[0029] S1: obtain the sampling signal from the power converter;

[0030] S2: Obtain the frequency of the sampling signal;

[0031] S3: Obtaining a compensation parameter call index number according to the frequency of the sampling signal, and querying a pre-stored compensation parameter table with the compensation parameter call index number to obtain a discrete compensation parameter table;

[0032] S4: Compensating the sampled signal with the discrete compensation parameter table to obtain a feedback signal, wherein the compensation parameter table is a discrete data table of correspondence between time and compensation amount obtained at the lowest frequency of the sampled signal.

[0033] In practical applications, the above steps are executed by a controller (such as a single chip microcomputer) of the power converter.

[0034] In practical applications, see Figure 2 The schematic diagram of the sampling signal compensation method of the power converter according to another embodiment of the present application further includes step S0 before step S1: obtaining the compensation parameter table.

[0035] Specifically, step S0 includes: performing data analysis and processing based on the sampled signal and the actual signal at the lowest frequency of the sampled signal to obtain the compensation parameter table.

[0036] Furthermore, step S0 includes: S01: determining the frequency range [fmin, fmax] of the sampled signal, where fmin is the lowest frequency of the sampled signal and fmax is the highest frequency of the sampled signal; S02: detecting the sampling signal and the actual signal at the lowest frequency fmin of the sampled signal to obtain the sampling delay time ΔT of the sampling signal relative to the actual signal; S03: obtaining a sampling compensation parameter expression based on the sampling delay time ΔT; S04: selecting a time interval, calculating the number of samples N in the time interval according to the sampling period TAD of the sampling circuit, and discretizing the sampling compensation parameter expression with t=n*TAD, where n=1, 2, 3,…, N, to obtain a discrete compensation parameter table corresponding to time and compensation amount, where N is a natural number.

[0037] In one embodiment, the principle of obtaining the compensation parameter table is explained by taking the input voltage of a sine wave as an example. Figure 3 The schematic diagram of the sampled voltage signal and the actual voltage signal of an embodiment of the present application is shown. As described above, step S01 is to determine the input voltage frequency range f∈[fmin, fmax], where fmin is the lowest frequency of the input voltage and fmax is the highest frequency of the input voltage. The corresponding maximum period Tmax=1 / fmin and the minimum period Tmin=1 / fmax. In actual applications, in different application environments, the input voltage may be at different frequency values. For example, for AC input voltage signals, their frequencies may be different in actual work and in different countries. For example, the industrial frequency in China is 50HZ and fluctuates up and down in actual work, while the industrial frequency in Europe and the United States is 60HZ and fluctuates up and down in actual work. Its frequency varies within a certain range, such as 45HZ to 63HZ.

[0038] Step S02 is to operate the power converter at the lowest frequency fmin of the input voltage, detect the actual input voltage signal Vin(t) and the sampled input voltage signal Vin_s(t) corresponding to the input voltage, and obtain the delay time ΔT of the sampled input voltage signal Vin_s(t) relative to the actual input voltage signal Vin(t). Figure 3 As shown, the sampled input voltage signal Vin_s(t) lags behind the actual input voltage signal Vin(t) by a delay time of ΔT. In practical applications, the sampling delay time ΔT can be determined in a variety of ways, such as the amplitude of the sampled input voltage signal and the actual input voltage signal, and this application does not limit this. In practical applications, it is also possible that the sampled input voltage signal Vin_s(t) leads the actual input voltage signal Vin(t) by a lead time of ΔT, that is, ΔT is a negative value at this time, or the sampled input voltage signal Vin_s(t) lags behind the actual input voltage signal Vin(t) by a delay time of ΔT with a negative value. For details, please refer to Figure 4 The schematic diagram of the sampled voltage signal and the actual voltage signal of another embodiment of the present application is shown. That is, in actual application, the present application does not limit whether ΔT is positive or negative.

[0039] For step S03, Figure 3 In the illustrated embodiment, assuming the actual input voltage signal function can be expressed as Vin(t) = VIN*sin(wt), the sampled input voltage signal function can be expressed as Vin_s(t) = VIN*sin[w(t-ΔT)]. The sampled input voltage signal represents the waveform before compensation, and the actual input voltage signal represents the waveform after compensation. This yields the sampling compensation parameter expression k(t) = |Vin(t) / Vin_s(t)|, or k(t) = |sin(wt) / sin[w(t-ΔT)]|, where VIN is the peak value of the input voltage; w = 2πfmin, t ≠ ΔT, and ΔT can be positive or negative. In other words, step S03 obtains the actual signal based on the sampled signal and the sampling delay time ΔT, and divides the actual signal by the sampled signal to obtain the sampling compensation parameter expression.

[0040] In step S04, using a centrally symmetrical sine wave as an example, the sampled compensation parameter expression for a half-cycle waveform needs to be discretized. The compensation parameters for the other half-cycle can then be obtained based on this half-cycle. Therefore, the time interval corresponding to the centrally symmetrical sine wave is selected as the half-cycle, i.e., [0, Tmax / 2]. The compensation coefficients for the other intervals can be obtained using this selected time interval [0, Tmax / 2]. In other words, in practical applications, a time interval is selected as the time interval from which the compensation parameters for the other intervals can be obtained. Assuming that the sampling period of the input voltage sampling circuit is TAD, the number of samples N = (Tmax / 2) / TAD (where Tmax / 2 is the length of the selected time interval) within the input voltage half-cycle Tmax / 2 can be calculated. According to the sampling compensation parameter expression, the corresponding sampling compensation parameter k (n*TAD) is calculated when t = n*TAD, where n = 1, 2, 3, ..., N. Then, a discrete compensation parameter table corresponding to time and compensation amount can be obtained: Table[N] = [k(TAD), k(2*TAD), k(3*TAD), ..., k(N*TAD)], which forms the compensation parameter table. Please refer to Figure 5 The embodiment of the present application shown in FIG. Figure 3 The waveform diagram of the compensation parameter k and time t corresponding to the waveform shown is shown in the figure. Figure 6 The embodiment of the present application shown in FIG. Figure 4The following figure shows the waveform diagram of the compensation parameter k and time t. The curve is the curve corresponding to the sampled compensation parameter expression, and the points on the curve are the compensation values ​​corresponding to the discrete time t = n * TAD, which is the presentation of the discrete compensation parameter table corresponding to time and compensation value on the curve.

[0041] At this point, a compensation parameter table for compensating the sampling signal is obtained, and the compensation parameter table is stored in a controller, such as a single-chip microcomputer. When the power converter is actually controlled, the compensation parameter table is called to obtain the compensated sampling signal and feed it back to the control loop. Using the compensated sampling signal as the feedback signal improves the accuracy of the feedback signal, further improving the electrical performance of the switching power supply, such as harmonic content, power factor, dynamic performance and ripple, and reducing the cost of the switching power supply.

[0042] As mentioned above, if the compensation parameter table is discrete, then compensation is also performed on discrete points in the adopted signal. Therefore, in practical applications, curve fitting can be performed on the compensated discrete points to obtain a continuous, compensated sampling signal, that is, the actual feedback signal is still continuous.

[0043] As described above, in practical applications, the frequency of the input voltage can vary between 45 Hz and 63 Hz. In the prior art, compensation calculations must be performed at each frequency to supplement the input voltage sampling signal, which consumes computing resources and increases the computation time. The present application obtains the compensation parameter table at the lowest frequency, making it compatible with compensation for input voltages at different frequencies, thereby consuming fewer computing resources and reducing the computation time.

[0044] Furthermore, in one embodiment of the present application, when obtaining the compensation parameter table in step S0, the actual operating parameters of the power converter are also considered, such as the actual operating temperature of the power converter. Of course, the factors that need to be considered can also be determined based on the actual application environment of the power converter or the actual needs of different products.

[0045] Therefore, in one embodiment of the present application, S01 further determines the temperature range [TEMP_MIN, TEMP_MAX] of the sampled signal, where TEMP_MIN is the minimum operating temperature of the sampled signal and TEMP_MAX is the maximum operating temperature of the sampled signal. S02 also obtains the sampling delay ΔT at the minimum operating temperature TEMP_MIN of the sampled signal. In other words, the compensation parameter table is obtained at the minimum frequency and minimum operating temperature of the sampled signal. This allows the compensation parameter table to accommodate compensation for sampled signals at different frequencies and temperatures, further reducing computational resources and shortening computational time.

[0046] Furthermore, in one embodiment of the present application, the sampled signal is still taken as the input voltage as an example, the amplitude and frequency of the input voltage are fixed, and within the range of [TEMP_MIN, TEMP_MAX], the temperature is adjusted with the lowest ambient temperature TEMP_MIN as the starting point and ΔTEMP as the step size, so that multiple temperature points TEMP(m) = TEMP_MIN + m*ΔTEMP can be obtained, where m = 0, 1, 2, ..., M, M = (TEMP_MAX-TEMP_MIN) / ΔTEMP, and the voltage sampling effective value VIN(m) at the corresponding temperature is measured at each temperature point. Then, according to the formula p(m) = VIN(m) / VIN(0), the ratio p(m) of the voltage effective value (VIN(m)) at each temperature to the voltage effective value (VIN(0)) at the lowest temperature can be obtained, and the function between the ratio p(m) and TEMP(m) is obtained by curve fitting: p(m) = f[TEMP(m)].

[0047] For further information, see Figure 7 The flowchart of obtaining a compensation parameter call index number based on the frequency of a sampling signal according to an embodiment of the present application is shown as follows. Specifically, step S3 includes: S31: calculating the index number step size using the formula step = fr / fmin, where fr is the actual frequency of the sampling signal; S32: sampling time t = t + TAD; S33: determining whether the sampling signal crosses zero at the current sampling time t; if not, proceeding to step S34; if so, proceeding to step S35; S34: setting a first index variable variable1 = variable1 + step, and a second index variable variable2 = variable1 + 0.5, and rounding the second index variable to obtain the index number index;

[0048] S36: Determine whether the index number index is greater than or equal to N. If not, proceed to step S37; if so, proceed to step S38. S37: Set the current index number index as the compensation parameter call index number and proceed to step S32. S38: Set N as the compensation parameter call index number and end. S35: Reset the index number index, the first index variable variable1, and the second index variable variable2, and proceed to step S32. The compensation parameter call index number is thus obtained and limited to the number of samples N generated within the time interval and the time interval within which the sampled signal is sampled. The compensation parameter call index number can then be used to query a pre-stored compensation parameter table to obtain a discrete compensation parameter table.

[0049] In practical applications, in order to supplement the sampling signal and obtain a feedback signal with higher accuracy, after obtaining a discrete compensation parameter table, the actual sampling signal is compensated with the discrete compensation parameter table to obtain the feedback signal.

[0050] In one embodiment of the present application, the discrete compensation parameter table obtained in step S3 can be directly used to compensate the actual sampling signal. For details, please refer to Figure 1 .

[0051] In another embodiment of the present application, the effect of temperature on sampling accuracy must be considered in practical applications. Therefore, step S38 is followed by step S39, which includes: obtaining the current operating temperature; querying the temperature compensation parameter curve to obtain the temperature compensation coefficient corresponding to the current operating temperature; and multiplying the discrete compensation parameter table in step S3 by the temperature compensation coefficient to obtain the discrete compensation parameter table in step S4. In this way, the temperature compensation coefficient corresponding to the current operating temperature is combined with the discrete compensation parameter table in step S3 to obtain the final discrete compensation parameter table, further improving the accuracy of the feedback signal. In this way, compensation for sampled signals at different frequencies and temperatures is more effectively compatible, meaning that only one compensation parameter table needs to be stored in the controller.

[0052] In another embodiment of the present application, the effect of temperature on sampling accuracy must be considered in practical applications. Therefore, step S38 is followed by step S39', which includes: obtaining the current operating temperature; querying the temperature compensation parameter curve to obtain the temperature compensation coefficient corresponding to the current operating temperature; and step S4 multiplying the compensation parameter obtained from the discrete compensation parameter table and the temperature compensation coefficient with the sampled signal to obtain the feedback signal. This further improves the accuracy of the feedback signal.

[0053] As mentioned above, since the compensation parameter table is obtained at the lowest frequency, the period corresponding to the compensation parameter table is the longest. Under the same calling period and sampling period, the compensation parameter table obtained by the above method corresponds to the largest number of points. Therefore, for the sampled signal with a higher frequency, by setting different calling index numbers, a discrete compensation parameter table for the sampled signal with a higher frequency can be obtained, which is compatible with sampled signals of different frequencies and can also be compatible with sampled signals of different waveform types, such as symmetrical, asymmetrical, center-symmetrical, etc.

[0054] As described above, in one embodiment of the present application, when the frequency of the sampled signal is equal to the lowest frequency of the sampled signal, the index number is accumulated in steps of 1.

[0055] As described above, in another embodiment of the present application, when the frequency of the sampled signal is greater than the lowest frequency of the sampled signal, the index number is accumulated in steps greater than 1, and the greater the frequency of the sampled signal, the greater the step size of the accumulated index number.

[0056] In practical applications, after obtaining the sampling signal, the above-mentioned compensation parameter table is used to compensate the sampling signal to obtain a compensated sampling signal, which can solve the problem of the sampling signal being delayed relative to the actual signal due to sampling delay, so that the feedback signal applied to the control loop is closer to the actual value of the sampling signal, thereby achieving better control effect.

[0057] Furthermore, the present application also provides a power conversion device comprising a power converter and a controller. The controller is configured to control the power converter based on a sampled signal, wherein the controller stores a compensation parameter table, wherein the compensation parameter table is a discrete data table corresponding to time and compensation amount, obtained at the lowest frequency of the sampled signal, and wherein the controller executes the above-described sampled signal compensation method for the power converter.

[0058] As mentioned above, the compensation parameter table stored in the controller is compatible with the compensation requirements of different working conditions. In the actual operation of the power converter, the compensation parameter table is queried according to the actual working conditions of the power converter to obtain appropriate compensation parameters, and the sampled parameters are compensated and calculated to obtain the compensated feedback signal. This improves the real-time and reliability of the control feedback, and improves the electrical performance of the power converter, such as harmonic content, power factor, dynamic performance and ripple.

[0059] In practical applications, the power converter may be an AC / AC converter, an AC / DC converter, a DC / DC converter, or a DC / AC converter. The sampled signal (i.e., the signal to be compensated) described in this application is an AC signal. The sampled signal may be any type of signal, such as a voltage signal, a current signal, or the like.

[0060] In one embodiment, the sampled signal may also be a DC signal. It can be understood that in this case, the values ​​of all compensation parameters in the compensation parameter table obtained are equal.

[0061] Although the embodiments of the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0062] Furthermore, the scope of the present application is not intended to be limited to the particular embodiments of the processes, machines, manufacture, compositions of matter, means, methods, and steps described in the specification. As will be readily understood by one of ordinary skill in the art from the disclosure herein, processes, machines, manufacture, compositions of matter, means, methods, or steps that perform substantially the same functions now exist or will later be developed or that achieve substantially the same results as the corresponding embodiments described herein may be utilized in accordance with the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. A sampling signal compensation method for a power converter, characterized in that: include: S1: obtain the sampling signal from the power converter; S2: Obtain the frequency of the sampling signal; S3: Obtaining a compensation parameter call index number according to the frequency of the sampling signal, and querying a pre-stored compensation parameter table with the compensation parameter call index number to obtain a discrete compensation parameter table; S4: Compensating the sampled signal with the discrete compensation parameter table to obtain a feedback signal, wherein the compensation parameter table is a discrete data table of correspondence between time and compensation amount obtained at the lowest frequency of the sampled signal.

2. The sampling signal compensation method of the power converter according to claim 1, characterized in that: Also included between step S1: Step S0: Obtaining the compensation parameter table, including: performing data analysis and processing based on the sampled signal and the actual signal at the lowest frequency of the sampled signal to obtain the compensation parameter table.

3. The sampling signal compensation method of the power converter according to claim 2, characterized in that: Step S0 includes: S01: Determine the frequency range [fmin, fmax] of the sampled signal, where fmin is the lowest frequency of the sampled signal and fmax is the highest frequency of the sampled signal; S02: At the lowest frequency fmin of the sampled signal, the sampling signal and the actual signal are detected to obtain a sampling delay time ΔT of the sampling signal relative to the actual signal; S03: Obtaining a sampling compensation parameter expression based on the sampling delay time ΔT; S04: Select a time interval, calculate the number of sampling times N in the time interval according to the sampling period TAD of the sampling circuit, discretize the sampling compensation parameter expression with t = n*TAD, where n = 1, 2, 3, ..., N, and obtain a discrete compensation parameter table corresponding to time and compensation amount, where N is a natural number.

4. The sampling signal compensation method of the power converter according to claim 3, characterized in that: S01 also determines the temperature range [TEMP_MIN, TEMP_MAX] of the sampled signal, where TEMP_MIN is the lowest operating environment temperature of the sampled signal and TEMP_MAX is the highest operating environment temperature of the sampled signal. In S02 , the sampling delay time ΔT is obtained under the lowest working environment temperature TEMP_MIN of the sampled signal.

5. The sampling signal compensation method of the power converter according to claim 4, characterized in that: Step S0 also includes: S05: Fix the amplitude and frequency of the sampled signal, and adjust the temperature within the range of [TEMP_MIN, TEMP_MAX], starting from the lowest temperature TEMP_MIN and with a step size of ΔTEMP. Measure the effective value of the sampled signal at each corresponding temperature to obtain a temperature compensation parameter curve corresponding to the temperature and the temperature compensation parameter.

6. The control method of a power converter based on sampling signal compensation according to claim 5, characterized in that: Step S3 includes: S31: Calculate the index number step size using the formula step = fr / fmin, where fr is the actual frequency of the sampling signal; S32: sampling time t=t+TAD; S33: Determine whether the sampling signal crosses zero at the current sampling time t. If not, proceed to step S34. If so, proceed to step S35. S34: Set the first index variable variable1 = variable1 + step, the second index variable variable2 = variable1 + 0.5, and round the second index variable to obtain the index number index; S36: Determine whether the index number index is greater than or equal to N. If not, proceed to step S37; if so, proceed to step S38; S37: Set the current index number index as the compensation parameter calling index number, and go to step S32; S38: Set N as the compensation parameter calling index number, and end; S35: Reset the index number index, the first index variable variable1 and the second index variable variable2, and enter step S32.

7. The control method of a power converter based on sampling signal compensation according to claim 6, characterized in that: After step S38, the method further includes S39: obtaining the current operating temperature; querying the temperature compensation parameter curve to obtain the temperature compensation coefficient corresponding to the current operating temperature; and multiplying the discrete compensation parameter table in step S3 by the temperature compensation coefficient to obtain the discrete compensation parameter table in step S4.

8. The control method of a power converter based on sampling signal compensation according to claim 6, characterized in that: After step S38, the process further includes step S39': obtaining the current operating temperature; querying the temperature compensation parameter curve to obtain the temperature compensation coefficient corresponding to the current operating temperature; Step S4 is to multiply the compensation parameter obtained from the discrete compensation parameter table, the temperature compensation coefficient and the sampling signal to obtain the feedback signal.

9. A power conversion device, characterized in that: include: Power converter; A controller for controlling the power converter based on a sampling signal, wherein the controller stores a compensation parameter table, wherein the compensation parameter table is a discrete data table corresponding to time and compensation amount obtained at the lowest frequency of the sampled signal, wherein the controller executes the sampling signal compensation method for the power converter according to any one of claims 1 to 8.

10. The power conversion device according to claim 9, characterized in that: The power converter is an AC / AC converter, an AC / DC converter, a DC / DC converter or a DC / AC converter.

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