Design of an Electrical Continuously Variable Transmission Based Wind Energy Conversion System

The electrical continuously variable transmission system is a very promising concept for variable-speed constant-frequency wind power generation due to its ability of seamless speed adjustment. In this paper, a novel wind energy conversion system based on electrical continuously variable transmission is proposed. This system combines the merits of two popular wind generation concepts: It enjoys high torque density like the permanent-magnet synchronous generator system and, also, it needs only a partial-scale converter like a doubly fed induction generator system. With a special doubly fed dual rotor structure, the system realizes both speed variation and power generation within one single machine, which makes it very compact. Besides introducing its structure and working principle, the design and performance analysis of the machine are presented in this paper. A prototype is made and tested for validation.