Calculation And Analysis On The End Leakage Reactance And Losses Of Double Canned Induction Motor

In this dissertation, the three-dimensional finite element calculation model ofthe double canned induction motor end magnetic field is established contraposedthe characteristic of the motor end structure. Then, the end leakage reactance andlosses are calculated and analyzed by using the time-harmonic FEM and thetransient FEM. In consideration of that the winding current of the motor drivenby inverter contains harmonic, the harmonic leakage inductance and losses arecalculated and analyzed.Firstly, based on the flux linkage and voltage equations, the relationshipbetween the end winding inductance, mutual inductance and leakage reactance ofequivalent circuit are deduced, and the end equivalent circuit is given. Then, theflux linkage method of end leakage reactance calculation is proposed. After that,the energy method of calculating the end leakage reactance based on the time-harmonic FEM and the transient FEM is deduced from the simplified equivalentcircuit. After the end magnetic field finite element model was established, thetime-harmonic FEM and transient FEM are applied to the end leakage reactancecalculation, and the results show agreement with the results of analytical methodbasically.Secondly, based on the established end magnetic field finite element model,the end structure parts losses of the double canned induction motor are calculated,and the loss distribution are given. The losses of variable harmonic are obtainedby the time-harmonic FEM and the transient FEM. Though comparison, theresults show agreement, and the losses focus on the tapered ring, press plate andthe stator end winding and rotor end winding. Finally, considering that the winding currents of the canned induction motordriven by inverter contain large harmonic currents, the stator end winding androtor end winding leakage inductance calculation method by using the time-harmonic FEM and the transient FEM are proposed under considering theharmonic current, and the results agree well with the fundamental leakageinductance. Then, the conclusion that the leakage inductance decrease with theincrease of the order of harmonic is got.