Fault ride through control for a delta connected induction motor with an open winding fault by controlling the zero sequence voltage

This paper presents a modified fault ride through method for use when open circuit winding faults appear on an induction motor drive. The work includes a new feedforward compensation term introduced into the zero sequence component of the dq reference voltages which considerably reduces current and torque ripple in the faulted motor drive. A method for extending the operating range under fault conditions by employing intelligent field weakening control is presented. Experimental results are presented which demonstrate the effectiveness of the complete system and show that it can be incorporated onto existing commercial drives as a simple software addition.