Frequency conversion adaptive protection control method and system based on dynamic vector correction

Abstract

The invention relates to a variable-frequency adaptive protection control method and system based on dynamic vector correction, and belongs to the field of power protection control. The method comprises the following steps: measuring an output instantaneous frequency through three-mode fusion; performing dynamic correction on the rotating coordinate system based on the instantaneous frequency to obtain a correction amplitude; performing three-domain confidence factor correction based on the correction amplitude to obtain a comprehensive confidence coefficient; cooperative compensation is carried out based on the comprehensive confidence coefficient and the instantaneous frequency, and the cooperative compensation comprises protection constant value adaptive compensation and excitation-synchronous cooperative compensation which are respectively used for compensating an over-current protection constant value and excitation voltage; and obtaining an error index, carrying out real-time closed-loop verification based on the error index, and optimizing cooperative compensation. Frequency conversion adaptive protection control is realized by means of dynamic vector correction, three-domain confidence evaluation, excitation-protection cooperative compensation and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power protection control, and particularly relates to a variable-frequency adaptive protection control method and system based on dynamic vector correction. BACKGROUND

[0002] The current power system protection control faces the challenge of frequency fluctuation. The traditional frequency measurement method (such as zero-crossing detection) has a significant error under harmonic interference, the FFT algorithm is affected by spectral leakage and has a slow dynamic response, and the phase-locked loop (PLL) is easy to lose lock when the frequency changes dramatically. Moreover, the existing protection setting value is usually set based on the rated frequency, which causes impedance calculation deviation when the frequency deviates, and thus causes distance protection misoperation or refusal. The excitation control can adjust the unit power, but lacks real-time cooperation with the protection system, which may exacerbate power swing during grid oscillation. In addition, the amplitude measurement does not consider the transformer core saturation effect caused by frequency fluctuation, which leads to the decrease of voltage protection sensitivity. Harmonic pollution and phase asymmetry further reduce the measurement reliability, and the existing method only judges the data validity through the threshold value, without quantifying the multidimensional confidence and without setting a reliable negative feedback regulation mechanism. SUMMARY

[0003] To solve the above problems in the prior art, the application provides a variable-frequency adaptive protection control method and system based on dynamic vector correction.

[0004] The purpose of the application can be achieved by the following technical solutions: A variable-frequency adaptive protection control method based on dynamic vector correction, the implementation of the variable-frequency adaptive protection control method includes the following steps: S1: measuring the instantaneous frequency by three-mode fusion, the three-mode fusion includes fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation; S2: performing dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain a corrected amplitude; S3: performing three-domain confidence factor correction based on the corrected amplitude to obtain a comprehensive confidence; S4: performing cooperative compensation based on the comprehensive confidence and the instantaneous frequency, the cooperative compensation includes adaptive compensation of protection setting value and excitation-synchronization cooperative compensation, which are respectively used for compensating the overcurrent protection setting value and the excitation voltage; S5: obtaining an error index, performing real-time closed-loop verification based on the error index, and optimizing the cooperative compensation.

[0005] Preferably, in the step S1, the fundamental wave zero-crossing detection specifically includes: collecting three-phase voltage signals and extracting one phase, and detecting the time interval of two adjacent zero-crossing points from negative to positive to obtain the instantaneous fundamental wave frequency. The FFT spectrum analysis specifically includes: adding a Hanning window to the three-phase voltage signal; performing FFT transformation to locate the spectrum line near the fundamental frequency, capturing the highest amplitude frequency and the frequencies adjacent to the highest amplitude frequency; and calculating the anti-harmonic frequency using a three-line interpolation method. The instantaneous vector differential is specifically as follows: extracting one phase of the three-phase voltage signal, obtaining an in-phase component and an orthogonal component through low-pass filtering; obtaining an instantaneous phasor amplitude and phase based on the in-phase component and the orthogonal component; and obtaining a high-frequency dynamic frequency based on the phase.

[0006] Preferably, the acquisition of the instantaneous frequency in step S1 specifically includes: Obtain the total harmonic distortion rate and frequency change rate of the three-phase voltage signal and obtain the adaptive weight, which is mathematically described as ,in, 、 and is the adaptive weight, is the frequency change rate, is the total harmonic distortion rate; The instantaneous frequency is obtained based on the instantaneous fundamental frequency, the anti-harmonic frequency, the high-frequency dynamic frequency and the adaptive weight, which is mathematically described as , is the instantaneous frequency, is the instantaneous fundamental frequency, To resist harmonic frequencies, is the high frequency dynamic frequency.

[0007] Preferably, the step S2 specifically includes: S201: Collect three-phase voltage signals and transform them into a two-phase rotating coordinate system through Clarke transformation and Park transformation to obtain voltage components in the rotating coordinate system; S202: Obtaining a correction angle based on the instantaneous frequency; S203: Performing dynamic correction of the rotating coordinate system based on the voltage component in the rotating coordinate system and the correction angle to obtain a corrected voltage component; S204: Obtain the correction amplitude based on the instantaneous frequency and the correction voltage component, which is mathematically described as: ,in, is the correction amplitude, To correct the voltage component, is the rated frequency, is the core saturation coefficient.

[0008] Preferably, the step S3 specifically includes: Obtaining frequency domain confidence factors based on the frequency change rate; obtaining an amplitude domain confidence factor based on the corrected amplitude; Obtaining the maximum phase difference between the three phases in the three-phase voltage signal; The comprehensive confidence factor is obtained based on the frequency domain confidence factor, the amplitude domain confidence factor, and the phase domain confidence factor.

[0009] Preferably, the adaptive compensation of the protection setting in step S4 is specifically: obtaining the original protection setting at the rated frequency, and obtaining the adaptive protection setting based on the comprehensive confidence and the instantaneous frequency, which is mathematically described as ,in, is the adaptive protection setting value, is the original protection setting value, For comprehensive confidence, the protection device is triggered when the detected current is greater than the adaptive protection set value.

[0010] Preferably, the excitation-synchronization coordinated compensation in step S4 is specifically: obtaining the phase difference between the machine and the grid, and obtaining the per-unit value of the excitation voltage compensation, which is mathematically described as ,in, is the per-unit value of the excitation voltage compensation, is the system mechanical inertia time, is the machine-network phase difference, is the steady-state voltage regulation gain, is the dynamic prediction gain, is the phase compensation gain, and the per-unit value of the excitation voltage compensation amount is output to the excitation regulator for compensating the excitation voltage.

[0011] Preferably, the step S5 specifically includes: After the coordinated compensation, the residual frequency deviation, the residual phase difference and the frequency change rate deviation are continuously detected and obtained, and the error index is obtained; Based on the error index, the steady-state voltage regulation gain, dynamic prediction gain and phase compensation gain in the collaborative compensation are reversely optimized, and the mathematical description is: ,in, is the optimized steady-state voltage regulation gain, dynamic prediction gain and phase compensation gain, is the error indicator.

[0012] A variable frequency adaptive protection control system based on dynamic vector correction, used to implement the variable frequency adaptive protection control method described above, comprising a three-modal fusion measurement module, an amplitude correction module, a confidence factor correction module, a collaborative compensation module, and a closed-loop verification module; The trimodal fusion measurement module is used to output the instantaneous frequency through trimodal fusion measurement, and the trimodal fusion measurement includes fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation; The amplitude correction module is configured to perform dynamic correction of a rotating coordinate system based on the instantaneous frequency to obtain a corrected amplitude; The confidence factor correction module is configured to perform three-domain confidence factor correction based on the corrected amplitude to obtain a comprehensive confidence degree; The cooperative compensation module is configured to perform cooperative compensation based on the comprehensive confidence degree and the instantaneous frequency, the cooperative compensation including adaptive compensation of a protection setting value and cooperative compensation of excitation and synchronization, respectively used for compensating the overcurrent protection setting value and the excitation voltage; The closed-loop verification module is configured to obtain an error index and perform real-time closed-loop verification based on the error index to optimize the cooperative compensation.

[0013] The present application has the following advantages: (1) The three-modal fusion is used to measure the accurate output instantaneous frequency, so as to overcome the measurement error possibly caused by the frequency fluctuation in the system operation process; (2) The rotating coordinate system is used to dynamically correct the amplitude, and the transformer core saturation effect caused by the frequency fluctuation is considered, so as to effectively improve the voltage protection sensitivity; (3) The adaptive protection setting value is dynamically adjusted according to the instantaneous frequency and the confidence degree, so as to reduce the protection misoperation rate in the frequency fluctuation scenario; (4) The real-time deviation in the system operation process is detected and corrected through the negative feedback adjustment mechanism, which is beneficial to the long-term stable operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to facilitate the understanding of those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0015] Figure 1 A flow chart of a variable frequency adaptive protection control method based on dynamic vector correction. DETAILED DESCRIPTION

[0016] In order to better understand the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the expression "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the words "approximately", "about", and similar words are used as terms of approximation, not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. In addition, in the present application, the order of the steps described does not necessarily represent the order in which the processes appear in actual operation, unless there is an explicit other limitation or can be derived from the context.

[0017] It should also be understood that expressions such as "comprises," "including," "having," "includes," and / or "comprising" are open rather than closed expressions in this specification, indicating the presence of the stated features, elements, and / or components, but do not exclude the presence of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than just the individual elements in the list. In addition, when describing embodiments of the present invention, "may" is used to mean "one or more embodiments of the present invention." And, the term "exemplary" is intended to refer to an example or illustration.

[0018] Unless otherwise defined, all terms used herein (including engineering and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this invention pertains. It should also be understood that, unless otherwise expressly stated herein, words defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0019] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] Example 1: See also Figure 1 , a variable frequency adaptive protection control method based on dynamic vector correction, comprising: S1: Output instantaneous frequency through trimodal fusion measurement to achieve real-time measurement of system frequency, especially when the frequency fluctuates rapidly. The trimodal fusion measurement includes fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation; S2: Performing dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain a correction amplitude for eliminating the amplitude error caused by frequency fluctuation; S3: performing three-domain confidence factor correction based on the correction amplitude to obtain a comprehensive confidence level; S4: performing coordinated compensation based on the comprehensive confidence and the instantaneous frequency, wherein the coordinated compensation includes protection setting adaptive compensation and excitation-synchronization coordinated compensation, which are used to compensate for the overcurrent protection setting and the excitation voltage, respectively; S5: Obtain an error indicator, perform real-time closed-loop verification based on the error indicator, and optimize the collaborative compensation.

[0021] In this embodiment, the output of instantaneous frequency through trimodal fusion measurement can be specifically implemented by the following steps: S101: The fundamental wave zero-crossing detection is specifically as follows: collect the three-phase voltage signal and extract one phase (usually phase A), detect the time interval between two adjacent zero-crossing points from negative to positive to obtain the instantaneous fundamental wave frequency, which is mathematically described as ,in, is the instantaneous fundamental frequency, is the zero-crossing time interval; S102: The FFT spectrum analysis specifically includes: adding a Hanning window to the three-phase voltage signal to reduce spectrum leakage; performing FFT transformation to locate the spectrum lines near the fundamental frequency, capturing the highest amplitude frequency (i.e., the frequency corresponding to the highest amplitude) and the left and right adjacent frequencies of the highest amplitude frequency; and using the three-line interpolation method to calculate the anti-harmonic frequency, which is mathematically described as ,in, To resist harmonic frequencies, is the frequency of highest amplitude, is the frequency resolution (i.e. the ratio of sampling frequency to the number of sampling points), is the left adjacent frequency, is the right adjacent frequency, is the amplitude of the mth spectral line, is the amplitude of the m-1th spectral line, is the amplitude of the m+1th spectral line; S103: The instantaneous vector differential is specifically as follows: extract one phase of the three-phase voltage signal, and obtain the in-phase component and the orthogonal component by low-pass filtering, which is mathematically described as follows: ,in, is the in-phase component, are orthogonal components, is the rated frequency, is one phase of the three-phase voltage signal, is a low-pass filter; based on the in-phase component and the orthogonal component, the instantaneous phasor amplitude and phase are obtained, which can be mathematically described as ,in, is the instantaneous phasor amplitude, is the phase; based on the phase, the high-frequency dynamic frequency is obtained, which is mathematically described as ,in, is the high-frequency dynamic frequency; S104: Obtain the total harmonic distortion rate (take the maximum total harmonic distortion rate among the three phases) and the frequency change rate (the frequency change rate here is the frequency change rate obtained by direct detection) of the three-phase voltage signal, and obtain an adaptive weight, which is mathematically described as: ,in, 、 and is the adaptive weight, is the frequency change rate (Hz / s), is the total harmonic distortion (dimensionless); S105: Obtain the instantaneous frequency based on the instantaneous fundamental frequency, the anti-harmonic frequency, the high-frequency dynamic frequency and the adaptive weight, which is mathematically described as , is the instantaneous frequency.

[0022] In this embodiment, dynamic correction of the rotating coordinate system is performed based on the instantaneous frequency to obtain a correction amplitude, which can be specifically implemented by the following steps: S201: Collect three-phase voltage signals and transform them into a two-phase rotating coordinate system through Clarke transformation and Park transformation to obtain voltage components in the rotating coordinate system; The mathematical description of the Clarke transform is ,in, is the voltage component in the two-phase stationary coordinate system, is a three-phase voltage signal; the mathematical description of the Park transform is ,in, is the voltage component in the rotating coordinate system, is the rotor electrical angle.

[0023] S202: Obtain a correction angle based on the instantaneous frequency, which is mathematically described as: ,in, is the correction angle, is the rated frequency, is the differential gain (typical value 0.05), is the frequency change rate, is the time constant, generally the system response time; S203: Perform dynamic correction of the rotating coordinate system based on the voltage component in the rotating coordinate system and the correction angle to obtain a correction voltage component, which is mathematically described as: ,in, is the correction voltage component; S204: Obtain the correction amplitude based on the instantaneous frequency and the correction voltage component, which is mathematically described as: ,in, is the correction amplitude, is the core saturation coefficient (calibrated through no-load test, typical value is 0.002 / Hz).

[0024] In this embodiment, the three-domain confidence factors are modified based on the correction amplitude to obtain the comprehensive confidence, which can be specifically implemented by the following steps: S301: Obtain frequency domain confidence factor based on frequency change rate, mathematically described as ,in, is the frequency domain confidence factor, is the reference value of the frequency change rate (typical value is 5Hz / s); S302: Obtain an amplitude domain confidence factor based on the corrected amplitude, which is mathematically described as ,in, is the amplitude domain confidence factor, is the current correction amplitude based on the correction amplitude at the previous moment and the historical change trend prediction, is the system rated voltage amplitude; S303: Obtain the maximum phase difference of the three phases in the three-phase voltage signal and obtain the phase domain confidence factor, which is mathematically described as ,in, is the phase domain confidence factor, is the maximum phase difference between the three phases; S304: Obtain the comprehensive confidence based on the frequency domain confidence factor, the amplitude domain confidence factor, and the phase domain confidence factor, which is mathematically described as ,in, is the comprehensive confidence level. A comprehensive confidence level of 1 indicates absolute credibility, while a level of 0 indicates absolute untrustworthiness.

[0025] In this embodiment, collaborative compensation is performed based on the comprehensive confidence and the instantaneous frequency, which can be specifically implemented through the following steps: S401: The adaptive compensation of the protection setting value is specifically: obtaining the original protection setting value at the rated frequency, and obtaining the adaptive protection setting value based on the comprehensive confidence and the instantaneous frequency, which is mathematically described as ,in, is the adaptive protection setting value, is the original protection setting value, and the protection device is triggered when the detection current is greater than the adaptive protection setting value; S402: The excitation-synchronization coordinated compensation is specifically: obtaining the phase difference between the machine and the grid (the phase difference between the machine end and the grid) through the synchronization device, and obtaining the per-unit value of the excitation voltage compensation, which is mathematically described as ,in, is the per-unit value of the excitation voltage compensation, is the system mechanical inertia time, is the machine-network phase difference, is the steady-state voltage regulation gain (initial value 0.5), is the dynamic prediction gain (initial value 0.02), is the phase compensation gain (initial value 0.1), and the excitation voltage compensation value per unit is output to the excitation regulator to compensate for the excitation voltage. The mathematical description is: ,in, To compensate the excitation voltage, is the original excitation voltage.

[0026] In this embodiment, real-time closed-loop verification is performed based on the error indicator, which can be specifically implemented by the following steps: S501: After the coordinated compensation described in S4, the residual frequency deviation (i.e., the frequency deviation that still exists after compensation), the residual phase difference (i.e., the machine-network phase difference that still exists after compensation) and the frequency change rate deviation (the frequency change speed deviation that still exists after compensation) are continuously detected and the error index is obtained, which is mathematically described as ,in, is the error indicator, is the residual frequency deviation, is the residual phase difference, is the frequency change rate deviation, is the basic phase difference, is the basic frequency change rate deviation; S502: Based on the error index, reversely optimize the steady-state voltage regulation gain, dynamic prediction gain, and phase compensation gain in the collaborative compensation, which is mathematically described as follows: ,in, are the optimized steady-state voltage regulation gain, dynamic prediction gain and phase compensation gain.

[0027] Example 2: A variable frequency adaptive protection control system based on dynamic vector correction, comprising a three-modal fusion measurement module, an amplitude correction module, a confidence factor correction module, a collaborative compensation module and a closed-loop verification module; The trimodal fusion measurement module is used to output the instantaneous frequency through trimodal fusion measurement to achieve real-time measurement of system frequency, especially when the frequency fluctuates rapidly. The trimodal fusion measurement includes fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation; The amplitude correction module is used to perform dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain a correction amplitude for eliminating the amplitude error caused by frequency fluctuation; The confidence factor correction module is used to correct the three-domain confidence factors based on the correction amplitude to obtain a comprehensive confidence level; The collaborative compensation module is used to perform collaborative compensation based on the comprehensive confidence and the instantaneous frequency, wherein the collaborative compensation includes protection setting adaptive compensation and excitation-synchronization collaborative compensation, which are used to compensate for the overcurrent protection setting and the excitation voltage respectively; The closed-loop verification module is used to obtain an error index, perform real-time closed-loop verification based on the error index, and optimize the collaborative compensation.

[0028] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A variable frequency adaptive protection control method based on dynamic vector correction, characterized in that: The implementation of the variable frequency adaptive protection control method includes the following steps: Step S1: Outputting the instantaneous frequency through trimodal fusion measurement, wherein the trimodal fusion measurement includes fundamental wave zero-crossing detection, FFT spectrum analysis, and instantaneous vector differentiation; Step S2: performing dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain a correction amplitude; Step S3: performing three-domain confidence factor correction based on the correction amplitude to obtain a comprehensive confidence level; Step S4: performing coordinated compensation based on the comprehensive confidence and the instantaneous frequency, wherein the coordinated compensation includes protection setting adaptive compensation and excitation-synchronization coordinated compensation, which are used to compensate for the overcurrent protection setting and the excitation voltage, respectively; Step S5: Obtain an error index, perform real-time closed-loop verification based on the error index, and optimize the collaborative compensation.

2. The frequency conversion adaptive protection control method according to claim 1, characterized in that: The fundamental wave zero-crossing detection in step S1 is specifically as follows: collecting three-phase voltage signals and extracting one phase, detecting the time interval between two adjacent zero-crossing points from negative to positive to obtain the instantaneous fundamental wave frequency; The FFT spectrum analysis specifically includes: adding a Hanning window to the three-phase voltage signal; performing FFT transformation to locate the spectrum line near the fundamental frequency, capturing the highest amplitude frequency and the frequencies adjacent to the highest amplitude frequency; and calculating the anti-harmonic frequency using a three-line interpolation method. The instantaneous vector differential is specifically as follows: extracting one phase of the three-phase voltage signal, obtaining an in-phase component and an orthogonal component through low-pass filtering; obtaining an instantaneous phasor amplitude and phase based on the in-phase component and the orthogonal component; and obtaining a high-frequency dynamic frequency based on the phase.

3. The frequency conversion adaptive protection control method according to claim 2, characterized in that: The acquisition of the instantaneous frequency in step S1 specifically includes: Obtain the total harmonic distortion rate and frequency change rate of the three-phase voltage signal and obtain the adaptive weight, which is mathematically described as ,in, 、 and is the adaptive weight, is the frequency change rate, is the total harmonic distortion rate; The instantaneous frequency is obtained based on the instantaneous fundamental frequency, the anti-harmonic frequency, the high-frequency dynamic frequency and the adaptive weight, which is mathematically described as , is the instantaneous frequency, is the instantaneous fundamental frequency, To resist harmonic frequencies, is the high frequency dynamic frequency.

4. The frequency conversion adaptive protection control method according to claim 3, characterized in that: The step S2 specifically includes: S201: Collect three-phase voltage signals and transform them into a two-phase rotating coordinate system through Clarke transformation and Park transformation to obtain voltage components in the rotating coordinate system; S202: Obtaining a correction angle based on the instantaneous frequency; S203: Performing dynamic correction of the rotating coordinate system based on the voltage component in the rotating coordinate system and the correction angle to obtain a corrected voltage component; S204: Obtain the correction amplitude based on the instantaneous frequency and the correction voltage component, which is mathematically described as: ,in, is the correction amplitude, To correct the voltage component, is the rated frequency, is the core saturation coefficient.

5. The frequency conversion adaptive protection control method according to claim 4, characterized in that: The step S3 specifically includes: Obtaining frequency domain confidence factors based on the frequency change rate; obtaining an amplitude domain confidence factor based on the corrected amplitude; Obtain the maximum phase difference of the three phases in the three-phase voltage signal and obtain the phase domain confidence factor, which is mathematically described as ,in, is the phase domain confidence factor, is the maximum phase difference between the three phases; The comprehensive confidence factor is obtained based on the frequency domain confidence factor, the amplitude domain confidence factor, and the phase domain confidence factor.

6. The frequency conversion adaptive protection control method according to claim 5, characterized in that: The adaptive compensation of the protection setting in step S4 is specifically as follows: obtaining the original protection setting at the rated frequency, and obtaining the adaptive protection setting based on the comprehensive confidence and the instantaneous frequency, which is mathematically described as ,in, is the adaptive protection setting value, is the original protection setting value, For comprehensive confidence, the protection device is triggered when the detected current is greater than the adaptive protection set value.

7. The frequency conversion adaptive protection control method according to claim 6, characterized in that: The excitation-synchronization coordinated compensation in step S4 is specifically as follows: obtaining the phase difference between the machine and the grid, and obtaining the per-unit value of the excitation voltage compensation, which is mathematically described as: ,in, is the per-unit value of the excitation voltage compensation, is the mechanical inertia time of the system, is the machine-network phase difference, is the steady-state voltage regulation gain, is the dynamic prediction gain, is the phase compensation gain, and the per-unit value of the excitation voltage compensation amount is output to the excitation regulator for compensating the excitation voltage.

8. The frequency conversion adaptive protection control method according to claim 7, characterized in that: The step S5 specifically includes: After the coordinated compensation, the residual frequency deviation, the residual phase difference and the frequency change rate deviation are continuously detected and obtained, and the error index is obtained; Based on the error index, the steady-state voltage regulation gain, dynamic prediction gain and phase compensation gain in the collaborative compensation are reversely optimized, and the mathematical description is: ,in, is the optimized steady-state voltage regulation gain, dynamic prediction gain and phase compensation gain, is the error indicator.

9. A variable frequency adaptive protection control system based on dynamic vector correction, characterized in that: The system applies the variable frequency adaptive protection control method according to any one of claims 1 to 8, comprising a three-modal fusion measurement module, an amplitude correction module, a confidence factor correction module, a collaborative compensation module and a closed-loop verification module; The trimodal fusion measurement module is used to output the instantaneous frequency through trimodal fusion measurement, and the trimodal fusion measurement includes fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation; The amplitude correction module is used to perform dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain a correction amplitude; The confidence factor correction module is used to correct the three-domain confidence factors based on the correction amplitude to obtain a comprehensive confidence level; The collaborative compensation module is used to perform collaborative compensation based on the comprehensive confidence and the instantaneous frequency, wherein the collaborative compensation includes protection setting adaptive compensation and excitation-synchronization collaborative compensation, which are used to compensate for the overcurrent protection setting and the excitation voltage respectively; The closed-loop verification module is used to obtain an error index, perform real-time closed-loop verification based on the error index, and optimize the collaborative compensation.

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