基于晶闸管保护串联谐振型高压故障限流器用MOV工况分析及其关键技术的研究

Condition Analysis and Its Key Technology Research of MOA Used for the Thyristor Protection Series Resonant Type High Voltage Fault Current Limiter

基于晶闸管保护串联谐振型高压故障限流器是抑制电力系统短路电流的有效手段之一,已在国、内外的试点工作中得到成功试运行。笔者在基于晶闸管保护串联谐振型高压故障限流器工作原理的基础上,分析了电容器组过电压保护用MOV的稳态应力和暂态应力。深入研究了MOV的能量耐受能力,指出MOV在低幅值、长持续时间过电压作用下的失效模式主要是侧面闪络,其极限单位体积能量吸收能力约为300 k J/cm3。建议应用到串联谐振型高压故障限流器中的MOV选择使用电阻片侧面界面空间电荷不显著的类型。

Based on thyristor protection series resonant type high voltage fault current limiter is one of the effective means of short circuit current in power system, it has been successfully tested in pilot projects in China and abroad. Based on thyristor protection series resonant type high voltage on the basis of the principle of fault current limiter, the capacitor group overvohage protection with steady state stress and transient stress of MOV is analyzed. Further study of the MOV energy tolerance ability is carried out, it is pointed out that MOV under low-rising value, long duration of overvohage of flashover failure mode is mainly flank, its limit per unit volume energy absorption capacity of about 300 k J/era3. The energy tol- erance of the MOV is studied. It is pointed out that the failure mode under low amplitude and long dura- tion overvoltage mainly is side flashover. Therefore, the MOV mentioned above should be used in the con- dition that the space charge on the side surface of the resistor chip is not significant.