Magnet flux ing control of interior PM machine drives for improved response to short-circuit faults

This paper proposes a control method to the magnet flux in an interior permanent magnet (IPM) motor following short-circuit type faults in either the inverter drive or motor stator windings. Phase control is employed to implement the flux ing control method so that it is possible to take advantage of a zero sequence current in order to minimize the current in the shorted phase. It is shown that phase control results in a smaller induced current than employing a synchronous frame dq0 current regulator. The induced torque is also less than employing a purposely commanded symmetrical short-circuit in response to a short-circuit type fault. In the paper, the complete magnet flux ing control algorithm is derived with reference to the proposed phase current control method. The impact of controlling the zero sequence on the resulting phase currents is presented. Both simulation and experimental results are presented verifying operation of the proposed methods.