全光纤电流互感器电子单元改进设计研究

基于某换流站系统调试期间全光纤电流互感器电子单元直流电源单路空开试验出现的异常现象,通过多次试验分析发现故障原因在于电子单元的双电源失电告警扩展继电器,其复电瞬间产生高电压尖脉冲,电磁干扰影响光电流数据,产生测量故障和数据无效严重告警,最后提出双电源失电告警扩展继电器采用具有抗干扰能力的固态继电器替换传统电磁式继电器的改进设计方案,并通过定性分析、定量计算和试验验证了改进的方案可行,改进设计方案有效避免了单电源短时失电后复电引起特高压直流全光纤电流互感器数据测量故障导致保护动作闭锁直流。

Study of an improved electronic unit design of fiber optical current transformer

In view of anomalies in tests of one circuit air switches for DC power supply of an electronic unit for fiber optical current transformer (FOCT) in the course of system debugging in a converter station, it was detected through multiple tests and analysis that the faults originated from power loss of dual power supply of an electronic unit that warned the relay extension modules; in the instant of power recovery generated highvoltage pointed peaky pulses, and electromagnetic interference influenced photocurrent data and thereby resulted in measurement faults and serious warning of data invalid (DI). In the end, the paper proposes an improved design scheme of substituting antiinterference solid relay for traditional electromagnetic relay for the aforesaid problem. Moreover, feasibility of the proposed scheme is verified by qualitative analysis, quantitative calculation and tests. The improved scheme can prevent DC blocking by protection action resulting from data measurement fault of ultrahigh voltage DC FOCT due to power recovery after shorttime single power loss.