Research On The Variable Pitch Control Of The Tidal Current Turbines

Energy is the major problems of human society progress and development.Traditional fossil energy has been faced with depletion crisis,the environmental problems caused by the burning of fossil fuels also hinder human development,Energy and environmental issues have been the main problem faced by mankind in the 21 st century.More and more national pay attention to the tidal current energy renewable,non-polluting,high energy density advantages.Because the tidal current energy has the randomness and uncertainty,therefore,the research for the control technology of the tide power turbine is very practical significance.In this paper,25 kW turbine as the example to do a research on the Active Pitch Control technology.This paper begins with the study of Hydrodynamics of tide power turbine.Analysis of the whole process of Active Pitch Control,compared to the fixed pitch system,variable pitch hydro turbine can be kept to the minimum pitch angle to achieve the maximum power capture at low flow rates,and at the high flow rate can be kept to achieve constant power output through the variable pitch,Reduce the impact on the overload of system.Established the mathematical model of variable pitch control system,to satisfy the needs of tidal generator can be constant power control under high velocity flow.The treatment for the near of the rated operating point,to achieve the PID control of the tidal generator variable pitch control system.For its nonlinear,multivariable characteristic,this paper presents a unified variable pitch control system based on fuzzy control.Through the human experience to design the control statements,and in MATLAB/Simulink to the simulation.For electric pitch control,this paper designed a variable pitch drive system based on a DC brushless servo motor,and design a three closed loop control system of the motor current loop,velocity loop and position loop,and simulated.Simulation results show that the proposed tide power variable pitch system based on fuzzy control achieve the constant output power above the rated flow rate,and by comparison with the traditional PID control,fuzzy controller has the advantage of system fast responding speed,system no over regulation,and strong anti-interference ability.The design of the three closed-loop DC brushless servo system achieves the accurate tracking of the angles.