Patent ID: 6683435
Filing Date: 2004-01-27
Classification: B60L

Abstract:
A method of operating an electrical machine drive system that includes a three-phase electrical machine, and an inverter coupled to the three-phase electrical machine, the inverter including a first stage, a second stage, and a third stage, wherein the first stage is coupled to a first phase of the three-phase electrical machine, the second stage is coupled to a second phase of the three-phase electrical machine, and the third stage is coupled to a third phase of the three-phase electrical machine; and wherein each of the first stage, the second stage and the third stage includes an upper power switch and a lower power switch and the upper power switch has an upper diode coupled across the upper power switch and the lower power switch has a lower diode coupled across the lower power switch; the method comprising the steps of:opening the upper power switch and the lower power switch of each of the first stage, the second stage and the third stage of the inverter; and determining whether a diode or a power switch in the inverter is shorted.