On-line detection of winding short-circuits in inverter fed drives

A single shorted turn in invertor-fed AC motor drives results in very large fault currents and correspondingly serious consequences. Turn to turn faults are a common cause of machine failure and without rapid detection and appropriate post fault control, these faults will propagate rapidly. A fault detection scheme has been presented which works by comparing the sampled phase current to an expected value. Thus the detection method naturally forms an integral part of the current controller and requires no additional sensors. This detection scheme is sufficiently sensitive to detect a single shorted turn in the machine phase