The Study On Relevant Issues Of Voltage In Thewind Farm Considering The Randomness Of Wind Speed

Faced with an increasingly prominent issue about energy and environmental, there is a growing emphasis on the development and use of renewable resources. Wind power generation conducts a more mature pattern which renewable energy is used and is growing rapidly, the proportion of wind power is increasing in the power grid. Owing to wind power accessing to grid, it has changed the distribution of the original power flow, and made voltage stability and transient stability of the grid changed. Moreover, the random and intermittent of wind speed result in volatility of the output power in the wind farm, and they severely affected voltage quality to lead to the level of local voltage lessen, which becomes a major constraining factor in the development of wind farms. In this paper, the stability problems of wind farm accessing to grid have been studied, the main research contents include:(1) This paper establishes the wind speed model of the quarter method division and the transmission line model of the simplified wind power generation system, and it considers the slip ratio of the doubly-fed induction wind turbine and the randomness of power which wind turbine injects the system, after that then it derives dynamic voltage collapse index. And then it considered wind power system accessing to static var compensator to improve prevention capabilities of the system voltage collapse. The index provides a theoretical basis for dividing into voltage weak areas or areas of incident voltage collapse and real-time stability control.(2) On the basis of introducing the basic circuit structure, operating principle, mathematical model and control strategy of the static synchronous compensator, under the wind speed and three phase short fault disturbing, it studies and simulates relatively the example the of wind farm containing six stand-alone capacity of 1500kW of the double-fed induction wind turbine before and after accessing to the static synchronous compensator, the simulation results prove that the device can effectively improve the wind farm power quality and stability.(3) In allusion to basic structure, operating principle and mathematical model of the superconducting magnetic energy storage devices, and then this paper rationally design the proportional-integral-differential controller of power decoupled of the superconducting magnetic energy storage to suppress power fluctuations, thus smoothing the wind farm output power. Finally, it simulates and studies the wind farm containing six stand-alone capacity of 1500kW of the double-fed induction wind turbine, the results of simulation show that the superconducting magnetic energy storage devices improve the transient stability of wind farms to a certain extent.In this paper, using distribution network system joining up a single wind generator and the wind farm containing six stand wind turbines as examples, the simulation results show that the method is effective and practical.