A variable frequency adaptive protection control method and system based on dynamic vector correction

Abstract

The application 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: outputting an instantaneous frequency through three-mode fusion measurement; performing dynamic correction on a rotating coordinate system based on the instantaneous frequency to obtain a corrected amplitude; performing three-domain confidence factor correction based on the corrected amplitude to obtain a comprehensive confidence degree; and performing collaborative compensation based on the comprehensive confidence degree and the instantaneous frequency, wherein the collaborative compensation comprises protection setting value adaptive compensation and excitation-synchronization collaborative compensation, and is respectively used for compensating an overcurrent protection setting value and an excitation voltage; an error index is obtained; real-time closed-loop verification is performed based on the error index to optimize the collaborative compensation. The variable-frequency adaptive protection control is realized through dynamic vector correction, three-domain confidence evaluation and excitation-protection collaborative 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 causes distance protection misoperation or refusal. Although the excitation control can adjust the unit power, it lacks real-time cooperation with the protection system, and may exacerbate power swing during grid oscillation. In addition, the amplitude measurement does not consider the transformer core saturation effect caused by frequency fluctuation, resulting in a decrease in the sensitivity of the voltage protection. Harmonic pollution and phase asymmetry further reduce the measurement reliability, and the existing method only judges the validity of the data through a threshold value, without quantifying the multidimensional confidence and without 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:

[0005] 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:

[0006] 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;

[0007] S2: performing dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain a corrected amplitude;

[0008] S3: performing three-domain confidence factor correction based on the corrected amplitude to obtain a comprehensive confidence;

[0009] 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 for compensating overcurrent protection setting value and excitation voltage, respectively;

[0010] S5: obtaining an error index, performing real-time closed-loop verification based on the error index, and optimizing the cooperative compensation.

[0011] Preferably, the fundamental wave zero-crossing detection in the step S1 is specifically: collecting a three-phase voltage signal and extracting one phase thereof, detecting time intervals of two adjacent zero-crossing points from negative to positive to obtain an instantaneous fundamental frequency;

[0012] The FFT spectrum analysis is specifically: applying a Hanning window to the three-phase voltage signal; performing FFT transformation, positioning a spectrum line near the fundamental frequency, capturing a highest amplitude frequency and left and right adjacent frequencies of the highest amplitude frequency; and calculating an anti-harmonic frequency by using a three-line interpolation method.

[0013] The instantaneous vector differential is specifically: extracting one phase of the three-phase voltage signal, obtaining an in-phase component and a quadrature component through low-pass filtering; obtaining an instantaneous phasor amplitude and a phase based on the in-phase component and the quadrature component; and obtaining a high-frequency dynamic frequency based on the phase.

[0014] Preferably, the acquisition of the instantaneous frequency in the step S1 specifically includes:

[0015] The total harmonic distortion rate and the frequency variation rate of the three-phase voltage signal are acquired, and an adaptive weight is obtained, which is mathematically described as wherein, , and is the adaptive weight, is the frequency variation rate, is the total harmonic distortion rate;

[0016] 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, is the anti-harmonic frequency, is the high-frequency dynamic frequency.

[0017] Preferably, the step S2 specifically includes:

[0018] S201: collecting a three-phase voltage signal and converting to a two-phase rotating coordinate system through Clarke transformation and Park transformation to obtain voltage components in the rotating coordinate system;

[0019] S202: obtaining a correction angle based on the instantaneous frequency;

[0020] S203: performing dynamic correction of the rotating coordinate system based on the voltage components in the rotating coordinate system and the correction angle to obtain corrected voltage components;

[0021] S204: obtaining the correction amplitude based on the instantaneous frequency and the corrected voltage components, which is mathematically described as wherein, to correct the amplitude, to correct the voltage component, to correct the rated frequency, to correct the core saturation coefficient.

[0022] Preferably, the step S3 specifically comprises:

[0023] obtaining a frequency domain confidence factor based on the frequency change rate;

[0024] obtaining an amplitude domain confidence factor based on the corrected amplitude;

[0025] obtaining a three-phase maximum phase difference in the three-phase voltage signal;

[0026] obtaining the comprehensive confidence degree based on the frequency domain confidence factor, the amplitude domain confidence factor and the phase domain confidence factor.

[0027] Preferably, the protection setting value adaptive compensation in the step S4 specifically comprises: obtaining an original protection setting value under the rated frequency, and obtaining an adaptive protection setting value based on the comprehensive confidence degree and the instantaneous frequency, which is mathematically described as wherein, is the adaptive protection setting value, is the original protection setting value, is the comprehensive confidence degree, and the protection device is triggered when the detection current is greater than the adaptive protection setting value.

[0028] Preferably, the excitation-synchronization collaborative compensation in the step S4 specifically comprises: obtaining a generator-grid phase difference, and obtaining an excitation voltage compensation quantity unit value, which is mathematically described as wherein, is the excitation voltage compensation quantity unit value, is the system mechanical inertia time, is the generator-grid phase difference, is the steady-state voltage regulation gain, is the dynamic prediction gain, is the phase compensation gain, and the excitation voltage compensation quantity unit value is output to an excitation regulator for compensating the excitation voltage.

[0029] Preferably, the step S5 specifically comprises:

[0030] after the collaborative compensation, continuously detecting to obtain a residual frequency deviation, a residual phase difference and a frequency change rate deviation, and obtaining the error index;

[0031] based on the error index, reversely optimizing the steady-state voltage regulation gain, the dynamic prediction gain and the phase compensation gain in the collaborative compensation, which is mathematically described as wherein, The optimized steady-state voltage regulation gain, dynamic prediction gain and phase compensation gain, The error index is obtained.

[0032] A variable frequency adaptive protection control system based on dynamic vector correction is used to execute the variable frequency adaptive protection control method, and comprises a three-modal fusion measurement module, an amplitude correction module, a confidence factor correction module, a cooperative compensation module and a closed-loop verification module.

[0033] The three-modal fusion measurement module is used to output an instantaneous frequency through three-modal fusion measurement, and the three-modal fusion measurement comprises fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation.

[0034] The amplitude correction module is used to perform dynamic correction in a rotating coordinate system based on the instantaneous frequency, so as to obtain a corrected amplitude.

[0035] The confidence factor correction module is used to perform three-domain confidence factor correction based on the corrected amplitude, so as to obtain a comprehensive confidence degree.

[0036] The cooperative compensation module is used to perform cooperative compensation based on the comprehensive confidence degree and the instantaneous frequency, and the cooperative compensation comprises adaptive compensation of protection setting value and excitation-synchronization cooperative compensation, and is respectively used to compensate an overcurrent protection setting value and an excitation voltage.

[0037] 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 cooperative compensation.

[0038] The beneficial effects of the present application are as follows:

[0039] (1) The three-modal fusion measurement is used to accurately output an instantaneous frequency, so as to overcome the measurement error possibly caused by frequency fluctuation in the system operation process;

[0040] (2) The amplitude is dynamically corrected in a rotating coordinate system, and the transformer core saturation effect caused by frequency fluctuation is considered, so as to effectively improve the voltage protection sensitivity;

[0041] (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;

[0042] (4) The real-time deviation in the system operation process is detected and corrected through a negative feedback adjustment mechanism, which is beneficial to long-term stable operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0043] 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.

[0044] Figure 1A variable frequency adaptive protection control method based on dynamic vector correction. DETAILED DESCRIPTION

[0045] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed description is merely descriptive of exemplary embodiments of the present application and is not intended in any way to limit the scope of the present application. Throughout this specification, the expression "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the words "substantially", "approximately", and similar expressions are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in a measuring or computing process. In addition, in the present application, the order of the steps of the processes described does not necessarily indicate the order in which the processes occur in actual operation, unless explicitly limited or otherwise derivable from the context.

[0046] It should also be understood that expressions such as "include", "including", "have", "has", "contain" and / or "containing", and the like, are open-ended terms that are intended to mean one or more of the stated elements or components, but not excluding the presence of one or more other elements or components. In addition, when expressions such as "at least one of" appear after a list of elements, it means that at least one of the elements from the list is present, but does not exclude the presence of two or more of the elements from the list. Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0047] Unless otherwise defined, all terms used in this document, including engineering and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the words "comprise", "comprising", "have", "has", "contain" and / or "containing", and the like, are open-ended terms that are intended to mean one or more of the stated elements or components, but not excluding the presence of one or more other elements or components. In addition, when expressions such as "at least one of" appear after a list of elements, it means that at least one of the elements from the list is present, but does not exclude the presence of two or more of the elements from the list. Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0048] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0049] Example 1:

[0050] Please refer to Figure 1 A variable frequency adaptive protection control method based on dynamic vector correction, comprising:

[0051] S1: measuring output instantaneous frequency by three-modal fusion, realizing real-time measurement of system frequency, especially when frequency fluctuates rapidly, the three-modal fusion measurement including fundamental wave zero-crossing detection, FFT spectrum analysis and instantaneous vector differential;

[0052] S2: dynamic correction of rotating coordinate system based on the instantaneous frequency, obtaining corrected amplitude for eliminating amplitude error caused by frequency fluctuation;

[0053] S3: three-domain confidence factor correction based on the corrected amplitude, obtaining comprehensive confidence;

[0054] S4: cooperative compensation based on the comprehensive confidence and the instantaneous frequency, the cooperative compensation including adaptive compensation of protection setting value and excitation-synchronization cooperative compensation for compensating over-current protection setting value and excitation voltage respectively;

[0055] S5: obtaining error index, real-time closed-loop verification based on the error index, optimizing the cooperative compensation.

[0056] In the embodiment, the measuring output instantaneous frequency by three-modal fusion can be implemented by the following steps:

[0057] S101: the fundamental wave zero-crossing detection is specifically: collecting three-phase voltage signals and extracting one phase (generally selecting A phase), detecting time interval of adjacent two zero-crossing points from negative to positive to obtain instantaneous fundamental wave frequency, which is mathematically described as wherein, is instantaneous fundamental wave frequency, is time interval of zero-crossing points;

[0058] S102: the FFT spectrum analysis is specifically: adding Hanning window to the three-phase voltage signals for reducing frequency spectrum leakage; performing FFT transformation, positioning spectrum line near fundamental wave frequency, capturing highest amplitude frequency (i.e. frequency corresponding to the highest amplitude) and left and right adjacent frequencies of the highest amplitude frequency; adopting three-line interpolation method to calculate anti-harmonic frequency, which is mathematically described as wherein, is anti-harmonic frequency, is highest amplitude frequency, is frequency resolution (i.e. ratio of sampling frequency to sampling point number), is left adjacent frequency, is right adjacent frequency, is amplitude of mth spectrum line, is amplitude of (m-1)th spectrum line, is amplitude of (m+1)th spectrum line;

[0059] S103: the instantaneous vector differential is specifically: extracting one phase of the three-phase voltage signal, obtaining the in-phase component and the quadrature component through low-pass filtering, and the mathematical description is wherein, is the in-phase component, is the quadrature component, is the rated frequency, is one phase of the three-phase voltage signal, is low-pass filtering; obtaining the instantaneous phasor amplitude and phase based on the in-phase component and the quadrature component, and the mathematical description is wherein, is the instantaneous phasor amplitude, is the phase; obtaining the high-frequency dynamic frequency based on the phase, and the mathematical description is wherein, is the high-frequency dynamic frequency;

[0060] S104: obtaining the total harmonic distortion rate (taking the maximum value of the total harmonic distortion rate in three phases) and the frequency change rate (the frequency change rate here is the change rate of the directly detected frequency) of the three-phase voltage signal, and obtaining the adaptive weight, and the mathematical description is wherein, , and is the adaptive weight, is the frequency change rate (Hz / s), is the total harmonic distortion rate (dimensionless);

[0061] S105: obtaining the instantaneous frequency based on the instantaneous fundamental frequency, the anti-harmonic frequency, the high-frequency dynamic frequency and the adaptive weight, and the mathematical description is , is the instantaneous frequency.

[0062] In the embodiment, the dynamic correction of the rotating coordinate system is performed based on the instantaneous frequency, and the corrected amplitude is obtained, which can be specifically implemented by the following steps:

[0063] S201: collecting the three-phase voltage signal and converting to the two-phase rotating coordinate system through Clarke transformation and Park transformation to obtain the voltage component in the rotating coordinate system;

[0064] The mathematical description of the Clarke transformation is wherein, is the voltage component in the two-phase stationary coordinate system, is the three-phase voltage signal; the mathematical description of the Park transformation is wherein, is the voltage component in the rotating coordinate system, is the rotor electric angle.

[0065] S202: The correction angle is obtained based on the instantaneous frequency, mathematically described as follows: ,in, For the correction angle, For the rated frequency, This is the differential gain (typical value 0.05). The rate of change of frequency, The time constant is typically taken as the system response time.

[0066] S203: Based on the voltage component in the rotating coordinate system and the correction angle, perform dynamic correction of the rotating coordinate system to obtain the corrected voltage component, mathematically described as follows: ,in, To correct the voltage component;

[0067] S204: The correction amplitude is obtained based on the instantaneous frequency and the correction voltage component, mathematically described as follows: ,in, To correct the amplitude, The core saturation coefficient (calibrated through no-load testing, typical value 0.002 / Hz).

[0068] In this embodiment, a three-domain confidence factor correction is performed based on the correction amplitude to obtain the comprehensive confidence level, which can be implemented through the following steps:

[0069] S301: Frequency domain confidence factor is obtained based on the rate of change of frequency, mathematically described as follows: ,in, For frequency domain confidence factors, The reference value for the rate of change of frequency (typical value 5Hz / s);

[0070] S302: Based on the corrected amplitude, obtain the amplitude range confidence factor, mathematically described as follows: ,in, For the amplitude range confidence factor, This is the current correction magnitude predicted based on the correction magnitude from the previous moment and its historical trends. This refers to the system's rated voltage amplitude.

[0071] S303: Obtain the maximum phase difference of the three phases in the three-phase voltage signal and obtain the phase domain confidence factor, mathematically described as follows: ,in, For phase domain confidence factor, This represents the maximum phase difference between the three phases.

[0072] S304: The comprehensive confidence level is obtained based on the frequency domain confidence factor, the amplitude domain confidence factor, and the phase domain confidence factor, mathematically described as follows: ,in, This represents the overall confidence level. A confidence level of 1 indicates absolute reliability, while a confidence level of 0 indicates absolute unreliability.

[0073] In this embodiment, collaborative compensation based on the comprehensive confidence level and the instantaneous frequency can be implemented through the following steps:

[0074] S401: The adaptive compensation of the protection setting specifically involves: obtaining the original protection setting at the rated frequency, and obtaining an adaptive protection setting based on the comprehensive confidence level and the instantaneous frequency, mathematically described as follows: ,in, For adaptive protection settings, The original protection setting is used; when the detected current exceeds the adaptive protection setting, the protection device is triggered.

[0075] S402: The excitation-synchronization coordinated compensation specifically involves: obtaining the phase difference between the generator and the grid (phase difference between the generator and the grid) through a synchronization device, and obtaining the per-unit value of the excitation voltage compensation, mathematically described as follows: ,in, This is the per-unit value of the excitation voltage compensation. For the system's mechanical inertia time, For the phase difference between the machine and the network, This is the steady-state voltage regulation gain (initial value 0.5). The gain is dynamically predicted (initial value 0.02). As the phase compensation gain (initial value 0.1), the per-unit value of the excitation voltage compensation is output to the excitation regulator to compensate the excitation voltage. Mathematically, this is described as follows: ,in, To compensate for the excitation voltage, This is the original excitation voltage.

[0076] In this embodiment, real-time closed-loop verification is performed based on the error index, which can be implemented through the following steps:

[0077] S501: After the collaborative compensation described in S4, the residual frequency deviation (i.e., the frequency deviation that still exists after compensation), residual phase difference (i.e., the machine-network phase difference that still exists after compensation), and frequency change rate deviation (the frequency change rate deviation that still exists after compensation) are continuously detected and obtained, and the error index is mathematically described as follows: ,in, For error indicators, This is the residual frequency deviation. For residual phase difference, For the deviation of the rate of change of frequency, Based on the basic phase difference, Deviation in the rate of change of the fundamental frequency;

[0078] S502: Based on the error index, reverse optimize the steady-state voltage regulation gain, dynamic prediction gain, and phase compensation gain in the collaborative compensation, mathematically described as follows: ,in, The optimized steady-state voltage regulation gain, dynamic prediction gain, and phase compensation gain are given.

[0079] Example 2:

[0080] A variable frequency adaptive protection and control system based on dynamic vector correction includes a three-mode fusion measurement module, an amplitude correction module, a confidence factor correction module, a collaborative compensation module, and a closed-loop verification module.

[0081] The three-mode fusion measurement module is used to output the instantaneous frequency through three-mode fusion measurement, so as to realize the real-time measurement of the system frequency, especially when the frequency fluctuates rapidly. The three-mode fusion measurement includes fundamental zero-crossing detection, FFT spectrum analysis and instantaneous vector differentiation.

[0082] The amplitude correction module is used to perform dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain the correction amplitude, which is used to eliminate the amplitude error caused by frequency fluctuations.

[0083] The confidence factor correction module is used to perform three-domain confidence factor correction based on the correction amplitude to obtain a comprehensive confidence level.

[0084] The collaborative compensation module is used to perform collaborative compensation based on the comprehensive confidence level and the instantaneous frequency. The collaborative compensation includes adaptive compensation for protection settings and excitation-synchronization collaborative compensation, which are used to compensate for overcurrent protection settings and excitation voltage, respectively.

[0085] The closed-loop verification module is used to obtain error indicators, perform real-time closed-loop verification based on the error indicators, and optimize the collaborative compensation.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope 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 frequency conversion adaptive protection control method includes the following steps: Step S1: Output the instantaneous frequency through three-mode fusion measurement, wherein the three-mode fusion measurement includes fundamental zero-crossing detection, FFT spectrum analysis, and instantaneous vector differentiation; Step S2: Perform dynamic correction of the rotating coordinate system based on the instantaneous frequency to obtain the correction amplitude; Step S3: Based on the correction amplitude, perform three-domain confidence factor correction to obtain the comprehensive confidence level; Step S4: Perform coordinated compensation based on the comprehensive confidence level and the instantaneous frequency. The coordinated compensation includes adaptive compensation for protection settings and excitation-synchronization coordinated compensation, which are used to compensate for overcurrent protection settings and excitation voltage, respectively. Step S5: Obtain error indicators, perform real-time closed-loop verification based on the error indicators, and optimize the collaborative compensation.

2. The variable frequency adaptive protection control method according to claim 1, characterized in that, The fundamental frequency zero-crossing detection in step S1 specifically involves: acquiring three-phase voltage signals and extracting one phase, and detecting the time interval between two adjacent zero-crossing points from negative to positive to obtain the instantaneous fundamental frequency; The FFT spectral analysis specifically involves: applying a Hanning window to the three-phase voltage signal; performing an FFT transform to locate spectral lines near the fundamental frequency, capturing the highest amplitude frequency and its left and right adjacent frequencies; and calculating the anti-harmonic frequency using a three-line interpolation method. The instantaneous vector differentiation specifically involves: extracting one phase from the three-phase voltage signal, obtaining in-phase and quadrature components through low-pass filtering; obtaining the instantaneous phasor amplitude and phase based on the in-phase and quadrature components; and obtaining the high-frequency dynamic frequency based on the phase.

3. The variable frequency adaptive protection control method according to claim 2, characterized in that, The acquisition of instantaneous frequency in step S1 specifically includes: The total harmonic distortion rate and frequency change rate of the three-phase voltage signal are obtained, and the adaptive weights are derived, mathematically described as follows: ,in, , and For adaptive weights, The rate of change of frequency, Total harmonic distortion (THD); The instantaneous frequency is obtained based on the instantaneous fundamental frequency, the antiharmonic frequency, the high-frequency dynamic frequency, and the adaptive weights, and is mathematically described as follows: , Instantaneous frequency, The instantaneous fundamental frequency, To resist harmonic frequencies, It is a high-frequency dynamic frequency.

4. The variable frequency adaptive protection control method according to claim 3, characterized in that, Step S2 specifically includes: S201: Acquire three-phase voltage signals and convert them to a two-phase rotating coordinate system through Clarke and Park transformations to obtain voltage components in the rotating coordinate system; S202: Obtain the correction angle based on the instantaneous frequency; S203: Based on the voltage component in the rotating coordinate system and the correction angle, perform dynamic correction of the rotating coordinate system to obtain the corrected voltage component; S204: The correction amplitude is obtained based on the instantaneous frequency and the correction voltage component, mathematically described as follows: ,in, To correct the amplitude, To correct the voltage component, For the rated frequency, This is the core saturation coefficient.

5. The variable frequency adaptive protection control method according to claim 4, characterized in that, Step S3 specifically includes: The frequency domain confidence factor is obtained based on the rate of frequency change. Based on the corrected amplitude, a confidence factor for the amplitude range is obtained; Obtain the maximum phase difference of the three phases in the three-phase voltage signal and obtain the phase domain confidence factor, mathematically described as follows: ,in, For phase domain confidence factor, This represents the maximum phase difference between the three phases. The overall confidence level is obtained based on the frequency domain confidence factor, the amplitude domain confidence factor, and the phase domain confidence factor.

6. The variable frequency adaptive protection control method according to claim 5, characterized in that, The adaptive compensation of the protection setting in step S4 specifically involves: obtaining the original protection setting at the rated frequency, and obtaining an adaptive protection setting based on the comprehensive confidence level and the instantaneous frequency, mathematically described as follows: ,in, For adaptive protection settings, The original protection settings, To assess overall confidence, the protection device is triggered when the detected current exceeds the adaptive protection setting.

7. The variable frequency adaptive protection control method according to claim 6, characterized in that, The excitation-synchronization coordinated compensation in step S4 specifically involves: acquiring the phase difference between the generator and the grid, and obtaining the per-unit value of the excitation voltage compensation, mathematically described as follows: ,in, This is the per-unit value of the excitation voltage compensation. For the system's mechanical inertia time, For the phase difference between the machine and the network, For steady-state voltage regulation gain, To dynamically predict gain, To compensate for the phase gain, the per-unit value of the excitation voltage compensation is output to the excitation regulator to compensate for the excitation voltage.

8. The variable frequency adaptive protection control method according to claim 7, characterized in that, Step S5 specifically includes: After the aforementioned collaborative compensation, the residual frequency deviation, residual phase difference, and frequency change rate deviation are continuously detected and obtained, and the error index is obtained. Based on the aforementioned error index, the steady-state voltage regulation gain, dynamic prediction gain, and phase compensation gain in the collaborative compensation are inversely optimized. Mathematically, this is described as follows: ,in, The optimized steady-state voltage regulation gain, dynamic prediction gain, and phase compensation gain are... This is an error index.

9. A variable frequency adaptive protection control system based on dynamic vector correction, characterized in that, The system applies the frequency conversion adaptive protection control method as described in any one of claims 1-8, including a three-mode fusion measurement module, an amplitude correction module, a confidence factor correction module, a collaborative compensation module, and a closed-loop verification module; The three-mode fusion measurement module is used to output the instantaneous frequency through three-mode fusion measurement, which includes fundamental 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 the correction amplitude; The confidence factor correction module is used to perform three-domain confidence factor correction 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 level and the instantaneous frequency. The collaborative compensation includes adaptive compensation for protection settings and excitation-synchronization collaborative compensation, which are used to compensate for overcurrent protection settings and excitation voltage, respectively. The closed-loop verification module is used to obtain error indicators, perform real-time closed-loop verification based on the error indicators, and optimize the collaborative compensation.

Images