A Multi-Pole Low Speed Doubly Fed Brushless Generator for Direct Driven VSCF Wind Power System

Doubly fed induction machines are widely used in large variable speed constant frequency (VSCF) wind power generation system due to low cost. However, the brushes and slip ring of the conventional doubly fed machine not only need regular maintenance but also reduce the reliability of the wind power system. There is currently a great deal of interest in directly driven generator without gears. The reliability and efficiency of the wind power generation system will be increased in a direct driven brushless wind generator. This paper introduces a multi-pole low speed doubly fed brushless generator (DFBG) for direct driven VSCF wind power system which not only keeps the low cost feature of the doubly fed wind generator but also increases the operation reliability due to the gearless and brushless structure. The design, simulation and control strategy of the DFBG are discussed in detail.