Research On Complex Control For Precise Wind Direction Of Hydraulicwind Turbine Yaw System

In recent years, energy and environmental issues become pressing and must be solved in today’s human survival and development. Wind energy as a renewable green energy, plays an important role in remission of energy and environmental crisis and wind power technology get more attention in various countries. Yaw control system as an important part of modern large wind turbines, for improving the utilization of wind energy has an important significance. Compared with the traditional yaw model, proportional valve controlled motor yaw system has advantages of compact structure, a higher power-to-weight ratio and the real-time adjustment to the transmission ratio. Meanwhile abandoned deceleration gearbox mechanism, so reducing the weight and cost of wind turbines. Therefore, has an important significance for the study of key technology of hydraulic type wind turbine yaw system.In the form of hydraulic motor with portional valve control to drive in yaw system, constructed a mathematical model of yaw angle position control system and frequency characteristic analysis method was used to study the stability of the system. In order to improve utilization rate of wind energy and power generation, large wind turbine yaw system need to complete impeller always aligning the wind direction. Due to the impact of the uncertainty of wind direction and wind vane accuracy, leading wind direction precision is not high. Therefore, a compound control method was proposed, that’s using the vane control when the wind direction changed in large range, and differential pressure feedback control when wind direction changed in small range. Adopting theoretical analysis and experimental research methods, suppression and key technology of pressure control for precision wind direction were mainly studied.Take for example of 850 k W hydraulic wind turbine, proportional valve controlled motor yaw system simulation model was built applying AMESim software and speed programming model, velocity feedforward control model, pressure feedback control model were built applying MATLAB/Simulink software and have co-simulated. The simulation results show that the yaw velocity shock can be inhibit effectively, as well as the precision wind direction of yaw system has been improved apparently. On the basis of theory and simulation analysis, built a simulation platform of 850 k W hydraulic wind turbine yaw system, the effectiveness of vane and pressure compound control method was verified, and laid foundation for improving power generation of hydraulic wind turbine.