Design and analysis of low-voltage residual current operated protective device

In view of problem that current residual current operated protective device could easily lead to serious interphase short circuit fault after single-phase leakage, the paper analyzed operating characteristics of a novel residual current operated protective device in low-voltage grid based on low-voltage three-phase residual current protection theory, and discussed general design principles of protector in low-voltage power supply system under different wiring systems. Following the design principles can control resonance parameters within a limited range, which avoids design blindness.