A method and apparatus for harmonic detection in a hybrid DC transmission system

Abstract

The present application relates to the technical field of hybrid DC power transmission system, and particularly relates to a harmonic detection method and device of a hybrid DC power transmission system. The method determines a segment duration based on a main frequency extracted from a component, and divides the component into signal segments according to the segment duration; determines a waveform consistency index according to the amplitude fluctuation similarity between adjacent signal segments; determines an initial harmonic confidence according to the waveform consistency index, the amplitude of the main frequency and the half-power bandwidth; determines a dynamic correlation degree between the component and the fundamental signal according to the system active power data and the amplitude variation characteristics of the component and the fundamental signal; determines an integer frequency coincidence degree according to the deviation degree of the main frequency of the component relative to the fundamental frequency; determines a comprehensive harmonic confidence of the component according to the dynamic correlation degree and the integer frequency coincidence degree; determines whether the component is a harmonic component according to the initial harmonic confidence and the comprehensive harmonic confidence, analyzes and outputs the electrical characteristic parameters of the harmonic component, thereby improving the accuracy of harmonic identification.

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