一种电流突变量选相元件的探讨

文中所探讨的相电流突变量选相元件,是利用单相接地故障时,两健全相相间电流突变量为零这一特征来得到的。实际系统故障时,系统正、负序阻抗可能会不相等,使得健全相相间电流突变量不为零,这将对该选相元件产生一定的负面影响。文中给出了相应的解决办法,并用现场的某次故障录波数据为例来进行验证说明。该选相元件物理意义明确,有较高的灵敏性和可靠性,RTDS试验数据验证了该选相元件的准确性。

Discussion of phase selection relay based on difference of phase currents

The fault phase selector discussed is based on the result that the fault component of sound phases is zero when a single-phase-to-ground fault occurs. On the spot, the positive and negative impedances of power system are not always equal, which may make the fault component of sound phases not be zero any more, consequently the result mentioned above will be invalid. Countermeasure is provided and tested by some fault recording data. The proposed phase selector is easy to realize and has good sensitivity and high reliability. It is evaluated by RTDS data.