Application Of Advanced Control Algorithm In Large Wind Turbine

With the depletion of traditional energy sources and the still strong demand for energy from social development,the structure of energy sources is moving towards diversification.The proportion of various new energy sources in the energy supply structure is increasing.Wind energy is a renewable and clean energy and is widely used in the field of power generation in various regions and countries in the world.It has been rapidly developed in recent years and shows an increasing trend of the capacity of a single wind turbine generator.Currently,Wind turbines with stand-alone capacity of 2MW are in operation.At the same time,the proportion of wind power connected to the power grid has been increasing.In Europe,large offshore wind farms such as the North Sea,the Irish Sea and the Baltic Sea have been built.Large-scale wind power bases have also been built in Jiuquan,Zhangjiakou and Hami in the PRC wind power.This paper firstly introduces the development history,current situation and future development trend of wind turbine,and analyzes the pros and cons of existing wind power generation technologies such as permanent magnet wind turbine and doubly-fed wind turbine.The authors analyzed the characteristics of wind power plants and concluded that due to the more serious environmental impact of wind power plants working in the field,the generator has time-varying and nonlinear effects due to temperature rise effect,hysteresis effect and saturation effect in the generator part.It is considered that the aerodynamic characteristics of the wind turbine blade also have obvious nonlinear characteristics.Due to the existence of time-varying and non-linear characteristics,the traditional controller can not well adapt to the control requirements of wind turbines in different states.Therefore,for wind turbine applications,it is necessary to study more advanced control algorithms.After comparing and researching a variety of advanced control algorithms,the author determined that the adaptive back-stepping control algorithm should be applied to the speed control of the generator part;Source control algorithm for pitch control of wind turbine.Adaptive back-stepping allows online estimation and correction of parameters that are affected by operating conditions.At the same time,the back-stepping method is suitable for the control of nonlinear systems by decomposing a large system into sub-systems not exceeding its order and designing the virtual control law for each subsystem.Therefore,the adaptive back-stepping method is more suitable for the speed regulation of the generator part with the dual characteristics of time-varying and non-linearity.Passive control theory has clear physical meaning and is closely linked with Lyapunov stability theory.It is an effective tool for designing nonlinear system controller.Therefore,it is applied to the design of variable pitch controller of wind turbine.The author's research work for the actual engineering application also made some exploration and research.In the research work of this paper,the current high performance digital signal processor chip F28335 is selected as the controller,and the adaptive back-stepping algorithm for motor speed control is programmed.In order to realize the model-based development,the development environment between Math Work's MATLAB and TI's DSP Integrated Development Environment(IDE)CCS is configured and the adaptive back-stepping control algorithm is programmed under the F28335 environment.