Improved phase difference correction method taking regard of power grid frequency change rate

Abstract

The invention discloses an improved phase difference correction method taking regard of the power grid frequency change rate. With respect to the improved phase difference correction method, based on the frequency change rate, the normalized frequency correcting value is corrected. Compared with a conventional method, the improved phase difference correction method taking regard of the power grid frequency change rate is more suitable for the frequency dynamic change condition, can achieve accurate and fast harmonic parameter measurement when the frequency fluctuation range is relatively large, the frequency change is uncertain even frequency collapse occurs, can accurately determine the change of the frequency change rate, and is beneficial to taking emergency control measures timely when the system frequency is abnormal to prevent grave electric system accidents such as large-scale power failure.

Description

technical field

[0001] The invention belongs to the technical field of electric power harmonic analysis, in particular to an improved phase difference correction method considering the frequency change rate of a grid. Background technique

[0002] The problem of power harmonics has attracted people's attention as early as the 1920s. With the rapid development of power electronics technology and the wide application of various nonlinear loads, harmonic pollution is becoming more and more serious. On-line measurement of power harmonics is an important technical means to control harmonic pollution. In recent years, the introduction and development of technologies such as micro-grid and new energy grid connection have provided a new application background for the accurate and rapid monitoring of power harmonic parameters. Fast Fourier transform (FFT) is one of the commonly used algorithms for power harmonic parameter measurement. Under synchronous sampling, the parameters of eac...

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