Patent ID: 7480124
Filing Date: 2009-01-20
Classification: H02H

Abstract:
1. A system that detects phase loss comprising: a three-phase rectifier component that converts three-phase AC power to DC power; a DC bus that provides DC power to one or more three-phase load devices; a detection component that measures a magnitude and a frequency of a three-phase AC voltage and measures a magnitude and frequency of a ripple voltage associated with a converted three-phase DC voltage; a converter component that converts an analog ripple voltage signal to a digital ripple voltage signal; a digital filter component that applies a Fast Fourier transform filter to the digital ripple voltage signal to isolate voltage components caused by single-phase operation from voltage components caused by standard operation of a three-phase load device; a firmware controller component that compares the magnitude and the frequency of the AC voltage to predetermined voltage characteristics indicative of a phase loss and compares the magnitude and frequency of the DC ripple voltage to predetermined voltage characteristics indicative of a phase loss and compares and compares the filtered digital ripple voltage signal to predetermined voltage characteristics indicative of a phase loss.