A strategy to isolate the switching device fault of a current regulated motor drive

An improved induction motor control topology is proposed which allows for continuous, disturbance-free operation of the drive with a failed short-circuited switch in one leg of the inverter. The approach utilizes low-cost thyristor/fuse technology to isolate the shorted switch, thereby permitting continued operation either by connecting the phase previously experiencing the fault back to the center point of the DC bus or, when insufficient voltage is available, by connecting the neutral back to the center point of the DC bus and simply operating with the two healty phases. The analysis of this control strategy and computer simulation are presented. Experimental results are used to verify the simulation results. A complete control strategy combined with short-circuit fault and open-circuit fault is included