Power system oscillation parameter recognition method and system, terminal and storage medium

Abstract

The invention belongs to the technical field of power systems, and discloses a power system oscillation parameter recognition method and system, a terminal and a storage medium. The method comprises the steps: achieving the separation of signals of different frequency bands through a band-pass filter; utilizing an improved variational mode decomposition (IVMD) method to extract an oscillation mode signal in each band-pass filtering signal; the HTLS algorithm and the adaptive artificial neural network algorithm Adaline ANN are combined to estimate the frequency, the attenuation factor, the amplitude and the phase of the low-frequency oscillation, and unified recognition of the wide-band oscillation is realized. According to the method, oscillation distinguishing, modal extraction and parameter recognition can be effectively carried out on multi-type and wide-band oscillation such as low-frequency oscillation, subsynchronous oscillation and super-synchronous oscillation from the operation data of the power system. The recognition result plays an important role in the aspects of system dynamic stability analysis and control, oscillation source recognition and positioning and the like, and early warning and timely suppression of system oscillation are facilitated.

Description

technical field [0001] The invention belongs to the technical field of power systems, and in particular relates to a power system oscillation parameter identification method, system, terminal and storage medium. Background technique [0002] At present, with the large-scale access of renewable energy, the wide application of power electronic equipment, and the large-scale interconnection of AC and DC, the modern power grid optimizes resource allocation and improves system reliability. At the same time, the number of weak links in the system increases and the anti-interference performance decreases. , new types of faults have appeared, and security and stability issues have become prominent. Oscillation is one of the problems that threaten the stable operation of the power system. The typical oscillations common in the current power system include: Low Frequency Oscillation (Low Frequency Oscillation, LFO) caused by regional or interval weak damping effects, and low-frequency...

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Problems solved by technology

[0007] (1) The model analysis method depends on the precise model of the system, large-scale systems and nonlinear power electronic devices will affect the accuracy of the model, resulting in analysis errors

[0008] (2) The Prony algorithm is highly sensitive to noise; mean filtering can only reduce noise interference but cannot filter out noise; the essence of wavelet denoising is to fit the signal in a specific frequency band, if there are multiple oscillation modes with similar frequencies , the wavelet method cannot distinguish them; methods such as Hilbert transform and singular value decomposition may have large errors when dealing with low signal-to-noise ratio signals

[0009] (3) Existing methods often identify oscillations with higher amplitudes during processing, and other oscillations may be considered as noise and ignored

[0013] Oscillation signals are often aliased together and covered by noise. If the oscillation parameters cannot be accurately identified from the aliased and noisy signals or all oscillation modes cannot be completely extracted, the oscillation of the power system will not be suppressed in time. As a result, the overcurrent trip of the tie line or the out-of-synchronization between the system and the system or between the unit and the system will cause a serious threat to the stability of the power system.

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