Research on Control System of High Power DFIG Wind Power System

Abstract

Compared with constant speed constant frequency wind turbine, variable speed constant frequency wind turbine has many advantages: higher efficiency of wind energy converting to electric power, absorbing gust energy, smoothly cutting into the network system, flexible connecting between wind turbine and network system and low operating noise. Currently the variable speed constant frequency technology has become one of the main development directions of wind power generation. A disturbance accommodating linear quadratic regulator (LQR) method was applied in pitch control system to achieve good performance. Based on the model of MW variable speed constant frequency wind turbine, this paper analyses three speed control methods, simulates corresponding characteristics of each method, and then gives discussions. On the condition of discussing and analyzing on simulation results and allowing for the characteristics of large power variable speed constant frequency wind turbine and its control system, this paper adopts power control closed-loop strategy to realize variable speed operating. At last, this paper designs a control system of MW variable speed constant frequency wind turbine, and takes sufficient experiments and long-time preliminary operation at a real wind farm, which validates the feasibility and practicability of varying speed control strategies on MW variable speed constant frequency wind turbine suggested in this paper.