Research On Intelligent Sliding Mode Variable Structure Control Of Variable Speed Wind Turbine

Because of the decrease and pollution of traditional nature resource of energy, the exploitation of new energy appears more emergent. Wind power is provided with cleanness, pollution-free and sustainable use, so it gets more and more attention. Wind power generation is the main form of use of wind, it plays an important role in changing energy structure and improving enviroment.Wind has the characteristics of low energy density, randomness and instability, and wind turbine is a system with multivariable, nonlinearity and uncertainty. To raise the utilization effiency and prolong the machine life, more researches are conducted all over the world. The tendency of wind turbine is:the unit capacity is still increasing; the control mode evolutes from fixed pitch stall-controlled mode to variable pitch. Now more researches concentrate on pitch control, generator control and grid-connection control. To raise the generated energy and generation effieccy, this article studies the variable pitch control of wind turbine.Build the sub-model of all parts of wind power generation system, inclueding wind model, transmission system model and generator model. The wind generation system nonlinear model can be obtained by combining all sub-models, the dynamic behaviour can be described.To improve the flexibility of transmission system and maintain the output power of wind turbine stablity in the conditon of high wind, a fuzzy sliding mode variable control is proposed by combining fuzzy control and sliding control by studying the characteristic of wind and wind turbine. It not only keeps the advantage of fuzzy control that doesn't need to build model but also can reduce the system order to simplify the complexity of control system which is shown in sliding control. In addition, combining fuzzy control and fuzzy control can weaken buffeting.Adopting the method of fuzzy sliding mode variable control, a simulation on wind turbine is conducted for the variable pitch control. The simulation results indicate that the control scheme can meet the demand.Moreover, a neural network sliding mode control is proposed and the simulation results show that the controller still has good performance.