高压直流输电系统换相失败的概率分析

换相失败是直流逆变系统最常见的动态故障，其概率分析是对传统确定性分析的一种重要补充。提出了换相失败的概率分析方法，给出了一组不同故障在不同时刻发生时熄弧角的计算公式。充分利用影响换相失败的因素之间的概率关系，考虑控制装置的快速调节作用，用Monte-Carlo模拟法统计计算换相失败的概率指标。所得结论对避免换相失败、保证直流系统稳定运行具有一定的指导意义。

PROBABILISTIC ANALYSIS OF COMMUTATION FAILURES IN HVDC TRANSMISSION SYSTEMS

Commutation failures are frequently occurred dynamic faults in high voltage direct current (HVDC) inverter stations. Probabilistic analysis of the commutation failures is an important reinforcement for the traditional deterministic analysis. A method of probabilistic analysis based on the commutation mechanism, including a set of formula used to calculate the maximum extinction angle under different dynamic conditions, is established. Making the best use of the effect of AC (alternating current) voltage disturbance at different time and magnitude on commutation failures and taking into account the rapid adjustment of controller, the probabilistic relation between the maximum extinction angle and the preset one is obtained and then the probabilistic indices are calculated by adopting Monte-Carlo simulation. The results of the CIGRE benchmark model show that by installing a supervisory equipment to detect the real-time voltage of valve side can avoid commutation failures effectively.