Mathematical Modelling and Parameter Determination of Reluctance Synchronous Motor with Squirrel Cage

The reluctance synchronous motor (RSM) is a machine working on the basis of development of reluctance torque development. The rotor configuration with the salient poles is made from the rotor of asynchronous motor if some rotor teeth are symmetrically removed (mill out). A different air gap in d and q axis enables development of a reluctance torque. The rotor cage is asymmetrical because some bars are located in the slots surrounded by iron and the other are surrounded by air, as it is shown in Fig. 1. This cage allows starting the motor directly from the grid, like the induction motors. In synchronous operation the cage acts as a damper of the oscillations in the speed. The cage parameters are important for the determination of the starting and running stability characteristics of the machine. Therefore in the past, several authors have focused on an analysis of the transient/starting performance of the RSM [1]-[5]. Mathur, [1] has created detailed mathematical model for the RSM with segmental rotor and winding on the rotor. He has derived an analytical expressions for the inductances calculation and made simulation of RSM. The coincidence between results from simulation and measurement was good but the analytical expressions were derived only for one type of rotor construction, what was unpractical.