Research on Intelligent Recognition for Weak Single-Phase-Earth Signal

To solve the low sensitivity and reliability of single-phase-earth signal detection, a novel fault line measuring and recognition method is proposed in basis of duffing oscillator theory which is sensitive to the special frequency signal and immune to noise. The fifth harmonic current is defined as measured parameter and added duffing oscillator equation. Then, the single-phase-earth line is detected according to the different state of system. The principle and program flow diagram of new method are given. Theory analysis and the simulation results show the weak current signal can be identified precisely and quickly using the proposed method.