The Low Voltage Ride Through Control For Direct Drive Wind Power Generation System

In recent years, with the vigorous development of China’s wind power industry, thecontrol of the wind power generation system operation with the low voltage drop throughalso becomes the one of the hot researches. This paper that is with the direct drivepermanent magnet synchronous wind power generation system as the object of study, onthe basis of the existing literature, mainly started a theoretical analysis and simulation forthe problems such as its running ability of low voltage through and the control strategy.Firstly, we introduced the development situation and development trend of the windpower system in recent years, conducted a comparative analysis of the two differenttypes of the wind power generation system, elaborated on the system composition andworking principle, analyzes and compares their respective advantages and shortcomings.Through the establishment of the mathematical model of the direct wind power system,analyzes the mathematical model of the wind turbine, the permanent magnetsynchronous generator , so as laid the foundation for its control strategy study.Secondly, we take the structure of the uncontrolled rectifier + Boost circuit + PWMinverter as the object of our study, on the basis of the analysis for two different traditionalcontrol strategies for the grid side converter, and analysis the basic idea on theachievement control ways for low voltage ride through, give out a new control strategyfor the low voltage ride through running and described in detail.Finally, in order to take the simulation studies and comparative analysis used thePSCAD/EMTDC for the low voltage side through control strategy in this paper, weestablished the simulation models for the three phase static var generator, the three phasevoltage source grid Converter and the direct drive wind power generator low voltage sidethrough control and analyzed the simulation results. The simulation results can beobtained that the given control strategy can be better to provide a reliable guarantee forthe system low voltage ride through capability and to provide some reference for theactual control system design.