Dissertation > Excellent graduate degree dissertation topics show

Study on Control Strategies of Doubly Fed Induction Generators Low Voltage Ride Through

Author: QianYeNiu
Tutor: LiGuoQing
School: Tohoku Electric Power University
Course: Proceedings of the
Keywords: Wind Power Double-fed asynchronous motor Low voltage ride through Feedback linearization Sliding mode control
CLC: TM315
Type: Master's thesis
Year: 2011
Downloads: 449
Quote: 0
Read: Download Dissertation

Abstract

In recent years, with the rapid development of wind power, wind power accounted for the proportion of the power grid is increasing every year. Some countries with higher wind energy utilization in Europe and the United States, such as Denmark and the United States by the end of 2009 the proportion of wind power supply were more than 20% and 10%. Some domestic regional power grid, such as the Inner Mongolia Autonomous Region Grid this ratio has reached 12.8%. The impact of wind power on the connected system is more and more obvious countries were introduced, in order to maintain the stable operation of the power system, wind power operation specifications and requirements and grid wind turbine low voltage ride through capability. Therefore, the research wind turbine low voltage ride through capability has important theoretical and practical significance. This paper first reviews the research status quo of domestic and international double-fed wind turbine low voltage across the control strategy and comparative analysis of the advantages and disadvantages of a variety of research methods. Then complete the establishment of a dynamic mathematical model of the doubly-fed wind turbine, and establish a vector control strategies based on the mathematical model. The control strategy includes the stator flux oriented voltage power decoupling control strategy and stator voltage oriented decoupling control strategy and simulation analysis, results show that the vector control when the wind turbine low voltage ride through capability is very limited. In order to further improve the doubly-fed wind turbine low voltage ride through capability, this paper proposes two new control strategies. One application of feedback linearization of nonlinear control method, dynamic mathematical model of the doubly-fed wind turbine based on the design of a low voltage across the control strategy. First, by controlling the target selected output function, the formation of the input and output of nonlinear systems; then by state feedback linearization and appropriate the coordinates transform the nonlinear system into a linear controllable system; final linear least Priority control method to complete the design of the system control strategy. The control strategy is only related to the parameters of the wind turbine, to improve the robustness of the control system parameters. Another sliding mode control method in the application of variable structure control design of low voltage across the control strategy. Firstly, by selecting the sliding surface system during exercise is divided into two phases, then combining Lyapunov function and stability the theorem were designed different stages of the control strategy, and combined to form the final fifth-order control strategy, and finally, by ignoring the stator flux changes designed to simplify the third-order control strategy. Considered outside interference in the design process of the control strategy, the uncertainty factor of system parameters on system modeling, to enhance the robustness of the control. Each method of simulation analysis, and has good control performance results show that the two control strategies to improve the ability to control of doubly-fed wind turbine low voltage ride through.

Related Dissertations

CLC: > Industrial Technology > Electrotechnical > Motor > Generators, large the generator group ( Zonglun,) > Wind turbines
© 2012 www.DissertationTopic.Net Mobile