Research On Modeling And Simulation Of Permanent Magnet Direct Drive Wind Turbine

Along with the enlargement of the scale of wind farm, a lot of work involved in modeling of wind turbine has been done by scholars, which brings out preliminary results, but the accuracy and reliability and rationality of the model are highly demanded more and more with the further study of wind power. PSCAD is an electro-magnetic transient simulation software in power system analysis, which is very popular all round the world. The precision of model elements assures that the model established is accuracy and reliable. At present, direct-drive permanent magnet synchronous wind turbine is one type of wind turbines widely used in our country. Compared with double-fed type wind turbine, direct-drive type wind turbine which occupies more and more proportion in the wind farms has some advantages such as lower wind speed operation, high efficiency, low follow-up maintenance costs and so on. In this paper, the model and simulation of direct drive permanent magnet synchronous wind turbine are researched.Firstly, this paper elaborates on detailed parts of the mathematical model of direct drive permanent magnet synchronous wind power generators, including the wind turbine components, shafting, permanent magnet synchronous generators, machine-side and network-side converter, etc., and gives out of detailed control strategy including pitch angle control, maximum power tracking control, machine side converter control, network-side converter control.Secondly, a detailed model of direct-drive permanent magnet synchronous wind turbine has been built based on PSCAD. The models of pitch control and maximum power tracking control has been built according to realities.Finally, when load changes, system required the necessary load reactive power compensation with the load disturbance.The characteristics of the model running at steady-state operation has been studied, and the results verifies the accuracy of wind turbine running in different sections of wind speed; Then, this paper has studied the response characteristics in the fluctuations of the machine side and the network side, specifically, in the grid fault, and the results match theoretical expectations. The above results show that the model built in this paper is accurate.