Losses Analysis of Induction Machines with Small Output Power

The main objects of this doctoral thesis are analysis of a small induction motor losses and research of ways how to reduce losses and increase efficiency of this motor. The ways how to reduce losses and increase efficiency under study are as follow: reduction of stator winding’s resistance, lengthening of magnetic circuit, modification of turn number, cooper squirrel cage, slots shape optimization, sheets annealing and use of sheets with lower specific losses. The losses analysis and the research of ways how to reduce losses are done due to laboratory work. For this laboratory work, eleven different samples of the motor with above mentioned modifications were manufactured. Results of their measurements and losses analysis are presented in this thesis. There were also simulations by finite elements method used to help solve objects of this thesis. Due to the simulations, analysis of loses of the induction motor under study was done. Results of this analysis include some details that are not included in the results from measurement, for example separation of core losses between rotor and stator. The simulations were also used for analysis of manufacturing technology impact onto the motor’s performance. During this analysis, following impacts were considered: actual shape of magnetic circuit, stator’s sheets riveting, influence of cutting onto material’s properties and placement of the stator into conductive frame. Results of this analysis are presented in this thesis