Induction motors with changeable pole windings in the ratio 1:4

Abstract

The paper presents a new three phase 4 to 16 pole-changing winding for an induction motor with 36 stator slots and 6 terminals. The principle of design is explained and the space harmonics are calculated for both of polarities. In order to obtain a higher fundamental winding factor and lower space harmonic content for 16-pole winding, a degree of non-uniformity was accepted for the slot filling factor. The winding is developed partially in single layer and partially in double layers and contains two types of coils wound by different wire diameter. An experimental motor with the new winding was built on a 6-pole base motor in the IEC frame 132 having the rated power of 4 kW for 4-poles (double star) and 1 kW (single star) for 16-poles. The test results have shown the validity of the design. The manufactured motor was modeled using 2D FEM field-circuit method in order to simulate the operation characteristics in the both speeds.