Design and optimization of electric continuous variable transmission system for wind power generation

Abstract

A novel brushless electric continuous variable transmission (E-CVT) system is presented and optimized. The proposed system offers an alternative solution for a variable-speed constant-frequency operation of the wind turbine application. The key is to eliminate the gearbox and brushes in the machine and this E-CVT system comprises of two rotors and two stators within one machine. This design inherits and integrates the merits of the direct-drive permanent magnet generator and the doubly fed induction generator with the additional benefit of the improved torque density and the need for a low-cost partial-scale converter. The structure, operation principle, and performance are analyzed. Genetic algorithm is employed to optimize the parameters for maximizing its power density. Time-stepping finite-element method is used to analyze the dynamic performance of the proposed system.