可控串联补偿电容器的过电压保护

Overvoltage Protection of Thyristor Controlled Series Capacitors

以补偿度取３６％ （其中２４％ 不可控、１２％ 可控）的伊敏－ 冯屯５００ ｋＶ 超高压输电系统为例，研究了以电容器电压为同步信号时可控串联补偿（ＴＣＳＣ）系统的内、外部故障、重合闸、电容重投时的过电压问题．提出了采用常规串补和可控串补相结合的补偿方案时ＴＣＳＣ装置过电压保护的参数整定原则：即以重合闸情况确定可控串补模块中氧化锌非线性电阻（ＭＯＶ）的整定参数，以外部故障确定固定串补模块中ＭＯＶ 的整定参数，最后以内部故障较核ＭＯＶ 的能量容量．讨论了重合闸和电容器重投时可采取的控制策略．

Based on the Yimin Fengtun 500 kV EHV transmission lines in which the compensation units consist of fixed series capacitors(FSC,24%) and thyristor controlled series capacitors(TCSC,12%), this paper studied overvoltages on TCSC due to short circuit fault, breaker reclosing, and reinsertion of series capacitors. It gave a rule for parameter settings of protective system of TCSC: the energy setting of metal oxide varistor(MOV) for TCSC should be based upon the energy absorbed in the case of breaker reclosing, while that of MOV for FSC is determined by external line section faults, then the capacities of MOV are checked by internal line section faults. For the sake of successful breaker reclosing and reinsertion of capacitors, a simple but effectual control strategy was put forward.