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CN-120652185-B - Oscillation characteristic parameter identification method, device, equipment and storage medium

CN120652185BCN 120652185 BCN120652185 BCN 120652185BCN-120652185-B

Abstract

The application provides a method, a device, equipment and a storage medium for identifying oscillation characteristic parameters, which are characterized in that an oscillation mode set with the amplitude of a spectrum peak value larger than a set threshold value is obtained by acquiring the spectrum of a signal to be processed; for each oscillation mode in the set, a corresponding mode tracker is constructed according to the initial frequency of the oscillation mode to track, the coefficients of the mode tracker are updated according to the difference value between the signal to be processed and the reconstruction signal, and the frequency, the amplitude and the phase of the oscillation mode are obtained according to the updated coefficients of the corresponding mode tracker. Through coarse granularity screening of the oscillation modes, each oscillation mode is tracked by utilizing the corresponding mode tracker, and accurate frequency, amplitude and phase of the oscillation mode are obtained according to the updated coefficient of the corresponding mode tracker, so that the parameter identification capability of the oscillation time-varying characteristics is improved, accurate power grid dynamic data are provided for power system operators, and safe and stable operation of the power system is ensured.

Inventors

  • MA NINGNING

Assignees

  • 清华大学

Dates

Publication Date
20260512
Application Date
20250611

Claims (11)

  1. 1. A method for identifying oscillation characteristic parameters, the method comprising: acquiring a frequency spectrum of a signal to be processed, and screening out an oscillation mode set with the amplitude of a frequency spectrum peak value larger than a set threshold value; For each oscillation mode in the oscillation mode set, constructing a corresponding mode tracker according to the initial frequency of the oscillation mode for tracking, wherein the output component of the mode tracker comprises the state and coefficient of the mode tracker; the current state of each mode tracker is weighted by the current coefficient of the mode tracker, the weighted results of all the mode trackers are combined to obtain a reconstruction signal, and the coefficient of the mode tracker is updated according to the difference value between the signal to be processed and the reconstruction signal; and obtaining oscillation characteristic parameters of each oscillation mode according to the updated coefficient of the corresponding mode tracker, wherein the oscillation characteristic parameters comprise frequency, amplitude and phase.
  2. 2. The method of claim 1, wherein the signal to be processed is a pre-processed signal, the pre-processing comprising: and processing the original signal by adopting a low-pass filter with a set cut-off frequency to obtain the signal to be processed with the high-frequency component suppressed, wherein the low-pass filter adopts a serial structure of an infinite impulse response filter and an all-pass filter.
  3. 3. The method of claim 1, wherein constructing a corresponding pattern tracker for tracking based on the initial frequency of the oscillation pattern comprises: And taking the initial frequency of the oscillation mode as the center frequency of the mode tracker, and initializing the state of the mode tracker according to the center frequency.
  4. 4. The method of claim 1, wherein weighting the current state of each mode tracker by the current coefficient of the mode tracker and combining the weighted results of all mode trackers to obtain the reconstructed signal comprises: for each mode tracker, multiplying the current state of the mode tracker by the current coefficient of the mode tracker; and summing the product results of all the mode trackers, taking a real part, and normalizing to obtain the reconstruction signal.
  5. 5. The method according to claim 1, wherein the obtaining the oscillation characteristic parameter of the oscillation mode according to the updated coefficient of the corresponding mode tracker includes: According to the phase change of the updated coefficient of the corresponding mode tracker, adjusting the center frequency of the mode tracker, and performing time smoothing on the adjusted center frequency to obtain the frequency of the oscillation mode; taking a mode from the updated coefficient of the mode tracker to obtain the amplitude of the oscillation mode; and calculating the amplitude angle of the coefficient updated by the mode tracker to obtain the oscillation mode phase.
  6. 6. The method according to claim 1, wherein the method further comprises: If the energy integral of the difference value between the signal to be processed and the reconstruction signal in the set time window is larger than a first threshold value, the frequency spectrum of the signal to be processed is acquired again, and an oscillation mode set with the amplitude value of the frequency spectrum peak value larger than the set threshold value is screened again; And if the frequency difference between the re-screened oscillation mode set and the existing oscillation mode is larger than a second threshold value and the duration is larger than a third threshold value, creating a corresponding mode tracker for the target oscillation mode, and initializing the state and the coefficient of the mode tracker corresponding to the target oscillation mode.
  7. 7. The method according to claim 1, wherein the method further comprises: In the existing mode tracker, if the amplitude corresponding to a mode tracker is smaller than a fourth threshold value and the duration is larger than a fifth threshold value, deleting the mode tracker; if the frequency corresponding to one mode tracker and the frequency corresponding to the other mode tracker are respectively converged to a first frequency and a second frequency, and the difference between the first frequency and the second frequency is smaller than a fifth threshold value, the frequencies, the amplitudes and the phases corresponding to the two mode trackers are respectively combined.
  8. 8. The method of claim 1, wherein the pattern tracker comprises a main pattern tracker for tracking an oscillation pattern of an initial frequency that is a fundamental wave and a harmonic of an integer multiple of the fundamental wave, and a sub pattern tracker for tracking an oscillation pattern of an inter-harmonic of an initial frequency that is a non-fundamental wave integer multiple of the frequency.
  9. 9. An oscillation characteristic parameter identification device, characterized in that the device comprises: The primary screening unit is used for acquiring the frequency spectrum of the signal to be processed and screening out an oscillation mode set with the amplitude value of the frequency spectrum peak value larger than a set threshold value; An updating unit, configured to construct a corresponding mode tracker according to an initial frequency of the oscillation mode for each oscillation mode in the oscillation mode set to track, where an output component of the mode tracker includes a state and a coefficient of the mode tracker; the current state of each mode tracker is weighted by the current coefficient of the mode tracker, the weighted results of all the mode trackers are combined to obtain a reconstruction signal, and the coefficient of the mode tracker is updated according to the difference value between the signal to be processed and the reconstruction signal; And the tracking identification unit is used for obtaining oscillation characteristic parameters of each oscillation mode according to the updated coefficient of the corresponding mode tracker, wherein the oscillation characteristic parameters comprise frequency, amplitude and phase.
  10. 10. An electronic device comprising a processor and a memory, the memory storing machine executable instructions executable by the processor for executing the machine executable instructions to implement the method of any one of claims 1-8.
  11. 11. A machine-readable storage medium having stored thereon machine-executable instructions which, when executed by a processor, implement the method of any of claims 1-8.

Description

Oscillation characteristic parameter identification method, device, equipment and storage medium Technical Field The present application relates to the field of online monitoring technologies of electric power systems, and in particular, to a method, an apparatus, a device, and a storage medium for identifying oscillation characteristic parameters. Background The wide-frequency oscillation dominant by the power electronic equipment is one of important factors threatening the safe and stable operation of the power system. However, due to the influence of the power grid operation mode and the control parameters of the power electronic equipment, the oscillation modes have time-varying characteristics, particularly dynamic changes of amplitude and frequency, so that the oscillation characteristic parameters are difficult to identify quickly, and a serious challenge is provided for accurately and quickly identifying the oscillation characteristic parameters of each oscillation mode. Disclosure of Invention In view of the above, the present application provides a method, apparatus, device and storage medium for identifying oscillation characteristic parameters, so as to solve the above technical problems. In a first aspect of the present application, there is provided an oscillation characteristic parameter identification method, the method comprising: acquiring a frequency spectrum of a signal to be processed, and screening out an oscillation mode set with the amplitude of a frequency spectrum peak value larger than a set threshold value; For each oscillation mode in the oscillation mode set, constructing a corresponding mode tracker according to the initial frequency of the oscillation mode for tracking, and updating the coefficients of the mode tracker according to the difference value between the signal to be processed and a reconstruction signal, wherein the reconstruction signal is obtained by weighting and combining the output components of all the mode trackers; and obtaining oscillation characteristic parameters of each oscillation mode according to the updated coefficient of the corresponding mode tracker, wherein the oscillation characteristic parameters comprise frequency, amplitude and phase. According to one embodiment of the present application, the signal to be processed is a signal after being preprocessed, and the preprocessing includes: and processing the original signal by adopting a low-pass filter with a set cut-off frequency to obtain the signal to be processed with the high-frequency component suppressed, wherein the low-pass filter adopts a serial structure of an infinite impulse response filter and an all-pass filter. According to one embodiment of the present application, the constructing a corresponding mode tracker according to the initial frequency of the oscillation mode for tracking includes: And taking the initial frequency of the oscillation mode as the center frequency of the mode tracker, and initializing the state of the mode tracker according to the center frequency. According to one embodiment of the application, the method further comprises: Multiplying the state generated by the mode tracker with the current coefficient of the mode tracker for each mode tracker; and summing the product results of all the mode trackers, taking a real part, and normalizing to obtain the reconstruction signal. According to an embodiment of the present application, the obtaining the oscillation characteristic parameter of the oscillation mode according to the updated coefficient of the corresponding mode tracker includes: According to the phase change of the updated coefficient of the corresponding mode tracker, adjusting the center frequency of the mode tracker, and performing time smoothing on the adjusted center frequency to obtain the frequency of the oscillation mode; taking a mode from the updated coefficient of the mode tracker to obtain the amplitude of the oscillation mode; and calculating the amplitude angle of the coefficient updated by the mode tracker to obtain the oscillation mode phase. According to one embodiment of the application, the method further comprises: If the energy integral of the difference value between the signal to be processed and the reconstruction signal in the set time window is larger than a first threshold value, the frequency spectrum of the signal to be processed is acquired again, and an oscillation mode set with the amplitude value of the frequency spectrum peak value larger than the set threshold value is screened again; And if the frequency difference between the re-screened oscillation mode set and the existing oscillation mode is larger than a second threshold value and the duration is larger than a third threshold value, creating a corresponding mode tracker for the target oscillation mode, and initializing the state and the coefficient of the mode tracker corresponding to the target oscillation mode. According to one embodiment of the application