Performance Analysis Of PMSG Under Different Wind Power Generation Systems Using Field-circuit Coupled Method

Permanent magnet synchronous generator (PMSG) is widely used in direct-drive wind power generation system (DWPGS) because of its high efficiency and reliability. Power electronic converter type’s selection for a direct-drive wind generation system with permanent magnet synclironous generator (PMSG) has significant impact on the operation performances of the PMSG, such as iron loss, copper loss, efficiency and power production. To quantitatively analyze such impact, in this paper field-circuit coupled method is proposed, which combines finite element model of PMSG, power electronic converter model and model of controllers for the converter. And the proposed method is applied to the performances evaluation on PMSG based direct-drive wind turbine systems equipped with two converter topologies. The simulation results above provide quantitative references for options and design of converter for DWPGS and the proposed method is a cost-effective way to estimate the performances of overall DWPGS without prototypes available. The concrete content is as follows:Firstly, the topology and principle of DWPGS has been analyzed. The mathematic models of wind turbine and PMSG are established, respectively, the computational models of the iron-loss, copper loss and eddy-current loss of PMSG are also introduced. For the converters in DWPGS, theirs principle have been analyzed. And also the process of realization of SVPWM is given.Secondly, On the basis of mathematical modeling, field-circuit coupled system of DWPGS is established in Ansys Maxwell, Simplorer and Matlab/Simulink. The settings of every software are given, the progress of the finite element model creation and mesh subdivision of PMSG is also introduced. The step of the entire field-circuit coupled simulation system is chosen appropriately.Finally, the comprehensive simulation is realized by Ansys Maxwell, Simplorer and Simulink coupled collaborative simulation stage. The current harmonics, power loss, torque ripple of the PMSG with different wind generation converter systems are analyzed quantitatively by of the proposed comprehensive model. Based on the simulation results, it can be found that the PMSG with back-to-back voltage source converter system has a lower current harmonics, torque ripples, loss and higher efficiency.