Study on the Influence Law of AC Asymmetrical Fault on HVDC System Commutation Failure
The asymmetric ac faults at dc system inverter side not only cause the decrease of the commutation voltage amplitude,but also bring offset to commutation voltage zero crossing point,leading to more complicated impacts on the dc system commutation failure than symmetric faults.In order to figure out the influence of ac faults on dc commutation failures more clearly, this paper analyzes the influence on turn-off angle of each valve in Y-bridge and D-bridge converters under different types of asymmetrical faults by theoretical derivation and summarizes the regularity of commutation failure valves and types under these faults.In addition,the study notices that under the same fault type, commutation failure type changes with different fault times.Theoretical results are analyzed and compared with the simulation results by a high voltage direct current (HVDC) system model built in PSCAD/EMTDC.
Asymmetric AC fault Commutation failure Fault time Y-bridge converterD-bridge converter
Yanting Wang Baohui Zhang
Department of Electrical Engineering, Xian Jiaotong University, Xian, 710049 China
国际会议
南京
英文
484-490
2015-09-21（万方平台首次上网日期，不代表论文的发表时间）