A new approach to improve steady state and transient responses of AFPM motor regarding demagnetization phenomenon

Abstract

In the ac machines, demagnetization phenomenon depending on its intensity alters the overall performance of machine via altering the waveform and amplitude of the Back EMF. By the way, due to existing complexity in the modelling of demagnetization, it has been considered hard to be taken into account precisely by the common design algorithm when designing the machine. Therefore this paper investigates a completed or modified approach for modelling and designing of the ac PM machines specifically an axial flux permanent magnet motor in which the demagnetization is intended to be considered properly. In other word this technique improves steady state response of machine .Some simulation results are presented in the paper all showing capability, accuracy and preference of the new procedure comparing with some way problematical classic and common design and modelling approaches. Moreover this paper illustrate the benefit of applying a damper cage as a method to improve transient response of motor in demagnetizing situation if for some reasons, reducing the armature currents is unavoidable in the transient operation regimes.