Modeling and control for a non-grid-connected wind power system based on a fixed-pitch variable speed wind turbine and a doubly salient generator

Dedicated to high energy-consuming industries, such as chloral-alkali, seawater desalination, and electrolytic aluminum, a novel non-grid-connected power generation (NGCPG) system is proposed; it is composed of a fixed-pitch variable speed wind turbine and a doubly salient DC brushless generator. The configuration of the non-grid-connected power system mentioned is presented. An equivalent model of the system is built based on analyzing and modeling each component. The control strategy, controlling the turbine speed by regulating load current based on turbine Cp-lambda curves, turbine torque curve and doubly salient generator electromagnetic torque characteristic, is proposed. The performance is as good as a variable-pitch wind turbine system can be achieved for such a fixed-pitch variable speed system mentioned with the control. System stability is analyzed with the proposed stable region, partT_a /partw less than partT_a /partw. Simulation results are given to verify the analysis.