Earth leakage current detection and identification scheme for a single-phase low-voltage electrical appliance system using frequency domain analysis

Abstract

This paper presents the frequency domain analysis approach for detection and identification of the earth leakage current in a group of electrical appliances connected to a single-phase low-voltage supply source. Once a leakage current occurs at an arbitrary appliance, an oscillator generates sine wave signal with particular frequency and injects it into a ground line. This signal is then monitored at grounding point in the main distribution board (MDB) and by using Fast Fourier transformation (FFT) for frequency domain analysis, defected appliances with earth leakage current can be detected and identified.