The Applied Research Of MCR In Wind Power Voltage Stability And Control

The energy shortage and environmental pollution in the world has become increasingly serious, wind energy as a renewable energy owns abundant reserves. It has important practical significance for the development and utilization of wind energy. To this end, all countries in the world race to develop wind power technology, the technology continues to mature and gradually improves. With the increasing capacity of the wind turbine, it has become an important content of the wind power technology research how to improve the efficiency of its operation and make maximum use of wind energy. At the same time, it has also become a hot research to maintain power voltage stability, security grid and achieve the standard of LVRT.The increasing of the grid-connected generating unit will cause a decline in voltage and power factor, so the corresponding reactive power compensation for wind farm is necessary. Reactive power compensation device contains MCR+FC, TCR and SVG. Compared to SVC, SVG has a big drawback that the smaller adjustment range, complex control technology and insufficient mature. So this paper will focus on MCR+FC dynamic reactive power compensation.Firstly, this paper introduces each part of the wind power generation system model. It focuses on the control schemes, pitch control and speed, the reactive power control solution are used. These control schemes reduce wind disturbance on wind power system output voltage stability. Then, analysis the wind farm electrical wiring and the equivalent of several commonly used model of wind farms. Lastly, establish wind turbines of partition segments equivalents and wind farm equivalent model.Secondly, this paper analyzes the working principle of MCR, mainly focuses on the analysis of the operating characteristics of MCR. It contains harmonic characteristics, the control characteristics and volt-ampere characteristics. Establish simulation model in Matlab. Focus on MCR+FC control method.Thirdly, this paper analyzes the wind turbines connected to the grid and introduces the theory of wind power system and asynchronous wind generators connected to power system. Then, expound the theory of the low voltage ride through and national standards on LVRT, and lay the foundation for verifying MCR+FC compensation effect. Analyze the principle and the dynamic model of doubly-fed induction motor. Focus on doubly-fed inductor motor equipped with Crowbar circuit, to realize the malfunction of the wind farm output, doubly-fed inductor motor rotor side removed by Crowbar. It makes that the wind turbines can run normally, to verify the installation on the effects of low voltage across Crowbar circuit through Matlab model.Finally, this paper puts forward a new type of reactive power compensation program-MCR+FC dynamic reactive power compensation program. Build MCR+FC dynamic reactive power compensation scheme in the wind power system simulation model, and comparative analysis of the wind farm output voltage waveform with the installation and not installation MCR+FC reactive power compensation device, when the wind farm output fluctuations and grid fault, it verifies the installation of MCR+FC reactive power compensation device that it can improve voltage greatly.