A brushless doubly-fed generator based on permanent magnet field modulation for wind power generation

A new brushless doubly-fed double stator double rotor (DSDR) generator based on permanent magnet field modulation for the wind power application is proposed in this paper. This generator adopted double stator to achieve the decoupling of the control winding and power winding. To improve the power density, a freely rotating rotor is introduced. To achieve the variable-speed constant-frequency operation and cancel the brush and slip ring, rotating field modulation ring is adopted to link with the wind turbine directly. In this paper, the operation principle of DSDR generator is detailed described. To verify the correctness of the principle, the performance of the DSDR generator is analyzed by the means of finite element analysis (FEA). The proposed DSDR generator owns the advantages such as low cost, low maintenance, high power density, high reliability, low speed direct driven, and good performance on grid fault ride-through. It has the potential on application of future large-scale wind power generation systems.