Research On Composite Rotor Structure Wind Generator For VSCF Power System

Wind power which is the most developed and largest generation mode of all the new energy will be the most prospective for commercial application.VSCF(variable speed constant frequency)is the most advantage wind power technology in the world. This is a new form of power generation, developed from 70s of last century. PMSG(permanent magnet synchronous generator)can be directly driven by the wind turbine, it has a simple structure, good ventilation, low speed, large inertia, high reliability and efficiency, and more suitable for direct-drive wind power system. Wind power generator is toward the direction of improving system reliability, reducing maintenance capacity, reducing components, reducing costs, increasing system efficiency and integration.In this paper, one structure of composite rotor for direct-drive and VSCF wind power system has been proposed. Two motors are connected by the planetary gear. Characteristic of the generator is an organic combination of electromagnetic system and mechanical system. Gearbox is embedded in the motor. When input speed of the motor changes, through the planetary gear differential regulation, generator achieves a constant output frequency, eliminating the need of stand-alone gear box for traditional wind power system, and the AC-DC-AC inverter link between the generator and power. Simplify the structure of the system. Auxiliary variable speed motor can balance the external input mechanical power and output power imbalances, improve energy conversion efficiency.The paper, based on the analysis of the various structural forms, study the design methods and match the techniques of electromagnetic system and mechanical system, optimize the parameters of electromagnetic system and mechanical system, give full play to the characteristics of the two systems, explore the best of the motor operation mode and control strategy, so that the motor can be the best match with Wind turbine and power system parameters.