Two phase operation for a three phase PMSM using a control model based on a Concordia like transform associated to a classic Park transform

In aerospace applications, high reliability drives are required. For electrical drives based on three phase PMSM, a way to improve the reliability is to allow a degraded mode operation on two phases only, thanks to specifically developed power and control architectures.The aim of this paper is to present a control strategy for the two phase operation which is supported by a model based on a Concordia like transform associated to a classic Park transform. This approach maintains the advantages related to the torque control in the Park reference frame: the two active phases are still supplied with sinusoidal currents, whose amplitude is proportional to the torque. By adjusting the phase shifts between these currents and the corresponding electromotive forces (EMFs), the torque ripple can be minimized or even canceled according to the EMF shape.