Effect of Rotor Barrier Pitch Angle on Torque Ripple Production in Synchronous Reluctance Machines

Abstract

This paper analyses the effect of rotor barrier pitch angles on torque ripple production in Synchronous Reluctance Machines (SynRMs), with the objective to reduce torque ripple contents in medium size ground Electric Vehicles (EVs). While keeping major-design parameters constant, the barrier pitch angle is varied by a quarter of the stator slot pitch. Three SynRMs having different rotor barrier pitch angles are designed and modeled using 2D Finite Element Method (FEM). The specifications of a traditional 5.5 kW, three-phase, 50 Hz, induction machine are used to design and model the SynRMs. Torque ripple reduction of ± 48 % is achieved for barrier pitch angles of 15 o and 17.5 o mech, when the machines operate at current space phasor angle of 45 o electric.