DC System Modeling and AC/DC System Harmonic Calculation under Asymmetric Faults

Haifeng Li, Junlei Liu, Fengjiao Wang, Gang Wang

School of Electric Power, SCUT, Guangzhou, China.

DOI: 10.4236/epe.2013.54B228                

Abstract

The accurate DC system model is the key to fault analysis and harmonic calculation of AC/DC system. In this paper, a frequency domain analysis model of DC system is established, and based on it a unified fundamental frequency and harmonic iterative calculation method is proposed. The DC system model is derived considering the dynamic switching characteristic of converter and the steady-state response features of dc control system synchronously. And the proposed harmonic calculation method fully considers the AC/DC harmonic interaction and fault interaction under AC asymmetric fault condition. The method is used to the harmonic analysis and calculation of CIGRE HVDC system. Compared with those obtained by simulation using PSCAD/EMTDC software, the results show that the proposed model and method are accurate and effective, and provides the analysis basis of harmonic suppression, filter configuration and protection analysis in AC/DC system.

Keywords

DC System Model; Harmonic Calculation; Switching Function; Asymmetric Faults

Conflicts of Interest

The authors declare no conflicts of interest.

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