Analysis and Optimization of Factors Influencing Current During MMC Bipolar Fault

doi:10.12204/j.issn.1000-7229.2020.05.015

Abstract

Abstract: Aiming at the bipolar short-circuit fault of flexible DC transmission system applying MMC， on the basis of the expression of single-terminal fault current， the effects of station-level control， valve-level control and operation level of converter station on fault current are analyzed in detail. Using the method of proof by contradiction， through the combination of theoretical calculation and simulation verification， this paper concludes that the station-level control does not affect the fault current， the valve-level control has a nonlinear influence on the fault current， and the operation level affects the fault-current growth rate and peak time within 6 ms after the fault occurred. According to the conclusions obtained， the valve-level control optimization measures that can limit the fault current are proposed. Finally， a four-terminal MMC model is built on the PSCAD/EMTDC simulation platform to verify the effectiveness of the proposed optimization measures.

Key words: modular multilevel converter (MMC), bipolar short circuit, fault current, control method, operation level

CLC Number:

TM 713

ZHANG Mingqi， LIU Qilin， ZHANG Yingmin. Analysis and Optimization of Factors Influencing Current During MMC Bipolar Fault[J]. Electric Power Construction, 2020, 41(5): 124-132.

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