Patent ID: 9727054
Date: 2017-08-08
CPC Classifications: E21B,G05B

Claim:
1. A method for detecting possible faults in subsea deployed power equipment electrically connected so as to be driven by a subsea deployed transformer, the method comprising: applying an alternating current (AC) voltage signal from a topside surface facility to a set of three-phase conductor cores of an umbilical cable connecting the surface facility to the subsea deployed transformer thereby generating flux in a core of the subsea deployed transformer, the AC voltage signal being insufficient to cause actuation of the subsea deployed power equipment connected to the subsea deployed transformer; measuring impedance amplitude and phase on the set of three-phase conductor cores; modeling an open circuit fault in the subsea deployed power equipment to generate one or more reference impedance amplitude and phase values associated with the set of three-phase conductor cores of the umbilical cable that indicate one or more open circuit fault conditions in the subsea deployed power equipment; comparing the measured impedance amplitude and phase with the reference impedance amplitude and phase values; and determining whether or not the open circuit fault is likely in the subsea deployed power equipment prior to first operation of the subsea deployed power equipment based on comparing the measured impedance amplitude and phase with the reference impedance amplitude and phase values.