Influence of the power electronic converter switching behaviour on the digital control of the VSI fed PMSM: characterisation and compensation

In PWM VSI fed surface-mounted PM synchronous motors, the torque control problem may be formulated in an elegant way as a single current tracking problem by using the Park transform or an appropriate extension of this transform if the machine flux distribution is nonsinusoidal. But when synthetizing the torque control in the Park or extended Park reference frame, a problem which is generally discarded is that the control voltages generated by the controller are given in the Park or extended Park reference frame and must be transformed into actual voltages by a PWM inverter. The aim of this paper is to characterise various effects of the finite value faith PWM frequency on the current tracking performance and to examine how to compensate them.