针对逆变侧交流故障下高压直流(line commutated converter-high voltage direct current,LCC-HVDC)输电系统易引发连续换相失败问题,该文分阶段分析了连续换相失败的产生机理.明确了当产生触发角偏差后,直流电流调节效果与实际触发角不匹配是连续换相失败的重要诱因.同时不对称故障后,负序分量通过极控、阀控两级控制系统对实际触发角造成的影响,增加连续换相失败的风险.因此提出了一种基于实际触发角响应的连续换相失败抑制方法,通过实际触发角修正整流侧电流指令值.与此同时,该方法通过陷波器降低负序电流对极控层触发角指令值的影响,通过相序解耦控制器和换相电压相位补偿降低负序电压对阀控层触发角实际值的影响.该方法能实现动态、自适应的电流指令值调整,提升恢复过程中直流电流与实际触发角的匹配度,提升直流系统抵御连续换相失败能力.在CIGRE标准测试模型和实际工程模型中,验证了理论分析的正确性和优化方法的有效性.
Continuous Commutation Failure Suppression Based on Actual Firing Angle Response
Aiming at the problem that a LCC-HVDC transmission system is apt to cause continuous commutation failures(CCF)under an AC fault on the inverter side,this paper analyzes the mechanism of CCF in stages.It is clear that when the firing angle deviation occurs,the mismatch between the DC current and the actual firing angle is an important cause of the CCF.If an asymmetric fault occurs at that time,the negative sequence component affects the actual firing angle through the pole control and the valve control system,which may increase the risk of CCF.Therefore,a CCF suppression method based on the actual firing angle response is proposed,in which the current command of the rectifier side is corrected by the actual firing angle.At the same time,the method reduces the influence of negative sequence current on the command of firing angle of pole control by the notch filter,and reduces the influence of negative sequence voltage on the actual value of firing angle of valve control by the sequence decoupled resonant and the commutation voltage phase compensation.This method is able to realize the dynamic and adaptive current command adjustment,improve the matching degree between the DC current and the actual firing angle in the recovery process,and promote the ability of DC system to resist the CCF.In the CIGRE model and an engineering model,the correctness of the theoretical analysis and the effectiveness of the optimization method are verified.
CCFactual firing anglevoltage dependent current order limiterphase-locked loopnegative sequence component
万方数据
维普
