Method for compensating frequency of phase angle sinusoidal modulation signal and frequency change rate

Abstract

The invention discloses a method for compensating frequency of phase angle sinusoidal modulation signal and frequency change rate. The method comprises the following steps of: performing a quadratic polynomial fitting on the frequency of phase angle sinusoidal modulation signal and frequency change rate to establish a filter matrix based on a least square method; performing spectral characteristicanalysis on the filter matrix, and obtaining a least square method to solve the error generation mechanism of the frequency of phase angle sinusoidal modulation signal and frequency change rate; obtaining a compensation formula of frequency and frequency change rate based on the primary filtering coefficient and the secondary filtering coefficient of the polynomial, and setting a compensation coefficient independent of the modulation frequency. By means of the method, when power oscillation occurs in the power system, the frequency and frequency change rate of which measurement precision better than that of a traditional quantity measuring method are obtained.

Description

technical field [0001] The invention relates to the technical field of synchronized phasor measurement, in particular to a compensation method for the frequency and frequency change rate of a phase angle sinusoidal modulation signal. Background technique [0002] Synchronized phasor measurement unit (Phasor Measurement Unit, PMU) is one of the effective tools for monitoring the dynamic process of the power system because of its rapidity and synchronization, and ensuring the measurement accuracy of the PMU under dynamic conditions is to accurately track the dynamic process of the power system premise. [0003] One of the more common dynamic processes in power systems is power oscillation. During oscillation, the phase angle will be sinusoidally modulated, causing the frequency and frequency change rate of the system to change sinusoidally with time. In addition to paying attention to the signal phasor amplitude and phase angle, the PMU, It is also necessary to measure the fr...

AI Technical Summary

Problems solved by technology

At present, the commonly used frequency and frequency change rate algorithms used in PMU are difference method and least squares method based on phase angle measurement. Both methods can obtain better measurement accuracy in steady state, but for power In dynamic situations such as oscillation, the measurement accuracy of frequency and frequency change rate is poor when the modulation frequency is large. Compared with the difference method, the least square method has a better noise suppression effect and has been better applied in practice. Therefore, it is very important to study the compensation method of the frequency and frequency change rate of the phase angle sinusoidal modulation signal based on the least squares method, and improve the measurement accuracy of frequency and frequency change rate, which is very important for system protection and control based on PMU measurement data and corresponding applications. role, but there is no such solution in the prior art

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