Research And Simulation Of Key Technologies Of Wind Power Generation Control System

In the early days of wind power generation,the fixed pitch wind turbine was mainly used.With the application and popularization of wind power generation technology,the shortcomings of the fixed pitch wind turbine appeared constantly,which made variable pitch wind power generation become the control core of wind power generation.Nowadays,the fixed pitch fan has been gradually replaced by the variable pitch fan.The principle of variable pitch is to adjust the pitch angle of the variable pitch system through the wind speed,so that it changes with the change of wind speed,and then change the blade angle of attack by changing the wind speed,so as to control the aerodynamic torque and power captured by the wind wheel.Variable pitch control has the following advantages:controlling the root of the wind turbine blade to withstand dynamic load,less static load,smooth output power after the rated point,full output power before the rated point,simple brake structure and so on.For the research of wind power generation technology,accurate mathematical model is the primary task.The dynamic model of wind turbine system is particularly important,and it is an important link to realize the control model of wind turbine.Through the design and analysis of the control model,it is helpful to the stable and reliable operation of the wind turbine and is put into actual production and operation.This paper simulates the model and control system established by MATLAB,and studies the key technology of variable pitch wind power generation.The wind power system model without controller is established in this paper.According to the characteristics of wind power generation,the magnitude of wind energy utilization coefficient and wind speed determines the magnitude of wind energy captured by wind turbines.When wind turbines work at low wind speed,they strive to capture the maximum wind energy.When wind turbines work at high wind speed,they pursue the output rated power to build a mathematical model for open-loop simulation.When the wind speed is higher than the rated value,the output of the wind turbine can not be stabilized near the rated value without a controller in the wind power system,so the corresponding constant power controller must be designed.On this basis,a variable pitch wind turbine model is established.The first order Taylor series is used to linearize the model to simplify the model,which is beneficial to the simulation without affecting the system.This fan model is only established near the equilibrium point of each working state of the wind turbine,that is,the balanceposition selected by linearization is the best position,that is,pitch angle is 3 degrees,in this case,the wind speed is rated.Aiming at the non-linearity of wind power generation system caused by the instability of natural wind,this paper studies the fractional order PID control algorithm based on the mathematical model.When the wind speed is in high wind speed period,the pitch angle is controlled by the continuous change of the output power of wind turbine,and the power generation system is controlled by the continuous change of pitch angle,so that the power generation system is more stable.The fractional order PID is applied to the pitch control system,which improves the control accuracy of the controller,stabilizes the output power and can better meet the power control requirements of the generator set.