| 摘要 |
A differential protective relay apparatus is switched over between a current differential mode and a voltage differential mode automatically by both even-order harmonic components of an input applied to a differential circuit and a voltage across an impedance of the differential circuit, thereby to cover extensive fault modes while retaining high minimum pickup sensitivity, furthermore, devised against excessive fault voltages in the voltage differential mode, and, consequently, advantageous in insulation withstand capability. |
