Research on Analysis and Suppression of Switching Overvoltage in Double-ended Flexible Low-frequency Transmission System

Le résumé fourni par la source

To tackle the problem that severe switching overvoltage are likely to occur in flexible low-frequency transmission systems following faults, this paper focuses on the analysis and suppression of overvoltage characteristics. By establishing an electromagnetic transient model of a double-ended flexible low-frequency transmission system, and considering typical fault conditions throughout the entire protection operation process, the expected switching overvoltage levels and distribution characteristics at key locations in the system are analyzed. A converter station switching overvoltage suppression scheme with surge arrester configuration is proposed. Calculation results show that the maximum switching overvoltage can reach 4.65 p.u. under a single-phase ground fault on the valve side of the low-frequency transformer; however, by configuring zinc oxide surge arresters, the overvoltage level can be reduced to 2.33 p.u. The research conclusions can provide a reference for the optimized design of overvoltage and insulation coordination in flexible low-frequency transmission systems.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.