Analytic modelling of a line-start permanent-magnet motor with slotted solid rotor

This study deals with an analytic model for slotted solid-rotor line-start permanent-magnet motors. The impact of non-linearity of solid-rotor impedance is taken into account in the proposed dynamic model by applying a numerical method. The rotor parameters are calculated as functions of rotor slip in the starting stage. Compared to the time-step finite element method, the proposed method is faster because, the rotor parameters can directly be utilised in the circuit model to simulate the transient start-up process of the line-start solid-rotor synchronous motors. Eventually, a four-pole, 250 V, 1500 rpm, 1050 W, three-phase synchronous motor with a slotted solid rotor is designed and prototyped to experimentally validate the capabilities of the proposed analytic model.