基于电流注入法的非对称短路开断试验(T100a)TRV参数计算与研究

Calculation and Study of TRV Parameters for Asymmetric Short-circuit Breaking Test(T100a) Based on Current Injection Method

高压交流断路器开断电力系统中的非对称短路故障时,由于短路电流是交流分量和直流分量的叠加,导致最后电流熄弧半波为大半波或小半波,电流过零熄弧点电源电压偏离峰值,暂态恢复电压(TRV)峰值将低于断路器开断对称短路故障情况下的数值。通过电流零点的对称短路故障(T100s)和非对称短路故障(T100a)的电流表达式,应用电流注入法原理,得出以T100s的TRV参考电压为基础,T100a的TRV参考电压的修正系数,以此来获得T100a在大、小半波开断时的TRV参考电压。研究内容为大容量试验站进行T100a试验时,评定TRV参数是否满足标准要求的范围,为试验时TRV调频装置L、R、C元件参数的调整提供了理论依据。

When the high-voltage AC circuit-breakers breaking the asymmetrical short-circuit fault in the power system, the short-circuit current is the superposed by AC component and DC component which resulting the last current arc-extinguishing loop is major loop or minor loop. Because the current zero point deviates from peak of the power supply voltage, the TRV peak will be lower than the value of symmetrical short circuit fault breaking. Based on the principle of current injection and TRV values of T100s, according to current expression of T100s and TlOOa, the correction coefficients of TRV values of T100a can be calculated for major loop or minor loop. Finally, the research of this paper can help to assess the TRV parameters of TlOOa test and adjust the R, L, C values of frequency modulation device in high power laboratory.