Energy Efficiency Class IE5 Magnet-Free Synchronous Reluctance Motor

Abstract

Modern synchronous reluctance motors allow improving energy efficiency of many industrial applications. The new standards define five classes of energy efficiency for electric motors, from IE1 to IE5. This paper considers issues related to the mathematical modeling and testing of a magnet-free synchronous reluctance motor of the highest energy efficiency class IE5. The proposed mathematical model allows calculating the efficiency factor, power factor, torque ripple, winding losses in the stator and rotor magnetic cores, and other operating characteristics of the synchronous reluctance motor run in various operation modes. The motor was tested on a test bench, which involved direct torque measurements. Thermocouples were used and measurements made in steady-state thermal mode to find the winding temperature. The body of the prototype synchronous reluctance motor has the same dimensions and rotation axis height as the body of the commercial IE3 induction motor of the same power. The results of a comparative test of the class IE5 prototype magnet-free motor and the class IE4 commercial motor are presented.