Harmonic Analysis of a DC/AC Hybrid Grid Using Resonance Modal Analysis

Abstract

This paper addresses the resonance problem in a DC/AC Hybrid Grid. Harmonic transfer between DC side and AC side causes various number of complicated harmonic resonance that threatens the system stability and power quality. In this paper, a method of harmonic resonance analysis is proposed to investigate the resonance problem in a Hybrid AC/DC system based on resonance modal analysis (RMA) and participation factor (PF) calculations. Using the analysis method of modeling interlinking converters and establishing a unified node admittance matrix, the traditional analysis range is extended to AC and DC networks. Then, RMA is introduced to study the resonance interaction of each node in the system. Specifically, the harmonic resonance is analyzed by establishing a unified node admittance matrix in the AC/DC hybrid distribution network, which considers the interaction of various harmonics in the AC/DC system. Finally, the analysis presented in this paper is verified based on frequency and time domain simulations in the Matlab/Simulink environment.