Harmonic Losses Numerical Analysis And Electromagnetic Design Optimization Of Brushless Doubly-Fed Machine

Brushless Doubly-Fed Machine（BDFM）has the excellent characteristics such asbrushless structure, high reliability, small capacity of its frequency converter, flexiblemodulation of its power factor and speed. Because BDFM can be used as a motor in ACadjustable speed drive system or as a generator in variable speed constant frequencygeneration system，it has wide applicable potentials. However，BDFM possesses largeharmonic losses and low efficiency, the completed design optimization method has notbeen built up yet. Based on the Project of State Key Laboratory of Power TransmissionEquipment&System Security and New Technology of Chongqing University, the thesisfocuses on the research of harmonic losses calculation and design optimization of theBDFM with cage rotor.Firstly, the basic structure, the operation modes and the electromagnetic designfeature of BDFM were briefly introduced. Then, based on2D time-stepping finiteelement model coupled with the circuit and the harmonic analysis method, two differentcalculation models of rotor copper loss and three different calculation models of statorand rotor iron losses were established respectively, and the influences of differentcalculation models on the rotor copper loss and the stator and rotor iron losses wereanalyzed. Thirdly, the data and variation tendency of BDFM harmonic copper and ironlosses were calculated and obtained by the Ansoft/Maxwell software. The correctness ofthe presented models and the calculated results was verified by the test data of the thirdparty. Fourthly, based on the analysis of standard Particle Swarm Optimization (PSO)algorithm, an improved PSO algorithm, the Oscillating Parameters and Adaptive EscapePSO (OPAE-PSO) algorithm, was proposed. The correctness of the OPAE-PSOalgorithm was verified by four benchmark functions. Finally, the design optimizationmodel of the BDFM with cage rotor was built up to maximize the efficiency by theOPAE-PSO algorithm and the optimization software was developed on the platform ofVisual Basic6.0. And then, a4.5kW prototype BDFM with cage rotor was optimizedby the software and the design data were discussed and compared. The results show thatthe OPAE-PSO algorithm is suitable for the design optimization of the BDFM with cagerotor and it can significantly improve the efficiency.The study of this thesis provides the theoretical foundation for the loss calculationand design optimization of the BDFM with cage rotor, and the design data are valuable for the manufacture of BDFM prototype.