Research On Intelligent Control Technology Of Variable Speed Variable Pitch Wind Power System

Today, all the world are facing the dual pressure of energy shortage and thedeterioration of ecological environment. In order to alleviate this pressure,manycountries are increasing in terms of policy, financial and technical guidance andsupport of new energy industry. In recent years, wind power occupies a pivotalposition in today’s new energy industry, and it has been acclaimed, and has beendeveloping rapidly. But it still faces many problems, such as high cost and frepuentaccidents, etc. So, increase the technical research and breakthroughs is very necessary.With higher wind energy conversion efficiency, run on a relatively safe andcontrol strategies easy to implement and other siginificant advantages, variable speedvariable pitch wind power system has become the mainstream model in the windpower market. In this dissertation, the mechanism modeling, the maximum powerpoint tracking, output power stability control and active control of the aerodynamicloads of the wind power aspects were studied. These aspects correspond to differentstages of wind turbine operation, including less power status and the rated power state,and the start-up phase and down phase are not the focus of this dissertation,so theywere ignored.Firstly, variable pitch control process is studied after analyzing the aerodynamictheory about wind turbine, built mathematical models for each unit of windturbine,and in Simulink.Secondly, because of the great nonlinearity of variable pitch wind turbine, theeffect of traditional PID control is not very perfect. So this paper proposes Fuzzy PIDpower control scheme, to improve the accuracy of power control. An objective-baseddynamic weighting fuzzy control model is presented considering to the forces of theblades,improved the overall response speed and performance of the variable pitchsystem composed of power control system and blade forces control system.Again, to solve the fuzzy controller capable of controlling its own steady-stateerror in eliminating the problem of weak systems, to further improve the accuracy ofoutput power control, PID control and fuzzy neural network control strategycombining design a fuzzy neural network PID controller. In addition, the effect ofwind speed measurement error of the force of the blade against former feedforwardcontroller designed to reduce the blade force.