接地故障下的SVC优化设计及其对后续换相失败控制策略

Optimization Design of Static Var Compensator and Its Control Strategy for Subsquent Commutation Failure with Grounding Fault

针对高压直流输电建设过程中存在的运行风险与故障影响,以交流侧常见的接地故障为问题导向,探索静止无功补偿器(SVC)的优化设计方法及其新型控制策略,以提高直流输电系统抵御后续换相失败的能力,保证接地故障条件下输电系统的运行稳定性。以故障发生时的换流母线电压跌落为判别依据,理论分析与结果对比表明通过合理配置固定电容器组(FC)和晶闸管控制电抗(TCR)中电感的容量,并对无功补偿过程中的FC切换与TCR触发角进行逻辑优化控制,不仅可以有效抵御后续换相失败的风险,还能解决SVC补偿过程中的电压"反调"。

In view of the operation risks and faults in the construction process of high-voltage direct current(HVDC) transmission, this paper takes the common grounding faults on the AC side as the solved problem orientation to explore the optimization design method of static var compensator(SVC) and its new control strategy and then to improve the ability of resisting the subsequent commutation failure to ensure the stability of transmission system with grounding fault. Based on the voltage drop of the convert bus when the fault occurs, the comparison between theoretical analysis and results show that when the inductor capacity in fixed capacitor(FC) and thyristor control reactance(TCR) is properly configured, and the FC switching and TCR firing angle are optimized and controlled logically in the process of reactive power compensation, it could not only effectively resist the risk of subsequent commutation failure, but also solve the voltage ‘reverse adjustment’ in the SVC compensation process.