The Research On Control System Of Wind Power Based On Variable Pitch

Wind energy is a kind of clean and inexhaustible energy. The objective requirements of environmental and energy make wind energy attached by more in-depth attention, and therefore clean wind power-based new renewable energy power generation is taking place of traditional fossil fuel-based power generation more and more.Despite of the increasing installed capacity at home and abroad, the increasing scale of wind farm construction, but some of the core control technologies of wind power are still immature, such as load optimization, low voltage ride through, independent pitch and damping control technology of tower. Therefore, it is highly significant to do the research on key control technologies of wind power generation. This paper aims to the control to wind energy utilization coefficient Cp which can raise the utilization rate of wind energy,control improve the maximum utilization of wind energy, and to the pitch control for constant power and the yaw control which is in view of wind direction.Firstly, from the perspective of aerodynamics and Electric Machinery Theories, this paper gives a controlled which is in line with actual requirements and implications, and this object model is based on the actual wind turbine. Because of the randomness of natural wind, from the perspective speed and wind direction we do research on it's influence on the power generation efficiency, mechanical limits and the wind energy utilization efficiency. For wind speed, different control strategies and control methods were used in different stages so that the largest generator of wind energy can not only absorb, but also make it a smooth transfer of power to the grid to ensure power quality and security of power supply. When lower than the rated wind speed, in pursuit of the largest wind energy absorbing target, the optimal speed control scheme were taken to make the contrast and analysis on the wind energy utilization coefficient Cp phase, and with output power with traditional look-up table method. The results show that the optimal speed control with a maximum Cp make wider use of wind speed range and a higher power output. When lower than the rated wind speed, the target of pursuit of a constant power output was accomplaced through the variable pitch adjustment. Because of the variable pitch wind turbine has a strong delay characteristics and nonlinear characteristics, the traditional PID control can not get contented control effect. In this paper, a fuzzy-PID switching control scheme was raised,at the low wind speed area, to a certain error threshold for the switch standard, when higher than the threshold, the fuzzy control was used, which is based on field experience to reduce the error rapidly and improve system Fast as the goal. When lower than the threshold, the PID control mathod was taken to improve the system stability as the goal. Similarly, at high speed area, the same strategy was taken, this is a combination of the advantages of both. Due to the spatial nonuniformity distribution of natural wind speed, wind speed model would be equivalent analysed. Wind turbine's dynamic model and wind speed model were built in MATLAB based on the above control strategy and mathod,from the simulation, the effect analysis and continuous improvement and perfection were carried out to achieve better results.Secondly, a semi-physical simulation platform was built based on a software-Bladed, a wind turbine model and the wind speed model was created in the software , link it with the system controller and do the simulation analysis.Finally, a research on the yaw control was did aims at wind direction. To ensure the efficiency of wind turbine power generation, in addition to the maximum speed tracking and pitch adjustment, but also to ensure that the wind rotor is always aligned, it is necessary to ensure that by the yaw control system. This paper analyzes the application of climbing method in the yaw system, and establish a fuzzy controller, did a simulation in MATLAB and achieved better control effect.