Study On Simulation Of Brushless Double-fed Wind Generator Control System

With the development of social economy, mankind's energy demand is growing. Energy shortages and environmental problems become increasingly serious, which lead to today's global energy crisis. Development of renewable energy is one of the ways to resolve this crisis. Relative to the solar energy, geothermal energy, tidal energy, bio-energy and other new energy sources, wind power resource is the fastest growing and the most promising renewable energy source in recent years.Brushless doubly-fed machine (BDFM) with variable speed constant frequency wind power generation technology achieves a dual-stator-fed. The BDFM not only has a simple rotor structure, but also has excellent properties the same as wound-rotor induction machine and synchronous machine. It is especially suitable for wind power generation. Because its power generation efficiency is high and the required inverter capacity is small, it has become the representitive of today's advanced wind power generation.This paper firstly introduced the development of wind power generation at home and abroad, described the characteristics of brushless doubly-fed machine and its research status, and analyzed strengths and weaknesses of several programs of variable-speed constant frequency wind power generation technology.Secondly, this paper analyzed BDFM's basic structure, operation principle, equivalent circuit and steady-state equation, discussed the steady-state characteristics; Analyzed BDFM's network mathematical model, rotor speed d-q coordinate mathematical model and double synchronous speed mathematical model. The BDFM will be decomposed into two subsystems—the power winding subsystem and the control winding subsystem. In the two subsystems, each variable of stator and rotor will be converted into DC value, which controls the motor speed, torque or power and so on. So it is easy for BDFM to implement control system.Subsequently, based on the rotor speed d-q coordinate mathematical model and under the MATLAB/Simulink environment, this paper established the BDFM's simulation model, studied on simulation performance of three types of operation mode. Then, based on this simulation model, according to BDFM's operating principle and fuzzy logic theory, this paper studied on fuzzy logic power factor control system of brushless doubly-fed wind power generation, designed a fuzzy logic controller which was applied into the brushless doubly-fed wind power generation system, and the simulation results proved that the intelligent control method can improve effectively the performance of this control system.Finally, this paper reviewed the research work and research results, looked to the follow-up work, and put forward several aspects that need to be improved.