Modeling and Studies of the Two-winding Three-phase Permanent Magnetic Synchronous Generator of Offshore Wind Turbines

With rapid development of wind turbine technology, 8-10 MW large direct-drive offshore wind turbines is under developing over the world. According to its large capacity and current rating, two-winding PMSGs (Permanent Magnetic Synchronous Generators) are design for theses turbines. However, the electro-magnetic effect of the two-winding PMSG is much more complex than ordinary single winding PMSGs. Unlike the small or medium system, the slot-leakage mutual inductance of 8-10 MW PMSGs cannot be ignored. Taking the slot-leakage mutual inductance into account, this paper derives the full-order model. Based on the proposed model, the influence of the slot-leakage mutual inductance is investigated. And then an equivalent parameter model that compatible with the conventional PMSG model is presented. After that, a method of obtaining parameters of the proposed model from commercial FEM (Finite Element Method) software is given. Finally, the accuracy of the proposed model is verified by FEM calculation, and two case studies on the operation of PMSG- IGCT (Integrated Gate Commutated Thyristor) converter system are carried out.