毕业设计（论文）-风电并网的电压波动研究精选.docVIP

毕业设计（论文） 题 目 风电并网的电压波动研究 风电并网的电压波动研究 摘 要 自然界中的风能是不确定的，当大规模的风电功率注入电网时会引起电网的电压波动。 本文首先分析了风电并网引起电网电压波动的本质原因是风电场输出功率的波动。以双馈型风力发电机组为研究对象，在Matlab/Simulink中搭建了双馈风电机组并网仿真模型。仿真分析了风电机组分别在恒电压和恒功率控制方式下切入后的运行特性及其对电网电压的影响，结果表明恒功率控制较恒电压控制方式具有更好的电压质量。风电场输出稳定后，分析了风速波动及风电场出口负荷波动对电网电压的影响，得出风速和负荷波动越严重，引起的电网电压波动越大。在风速随机波动的情况下，分析了系统短路容量和线路X/R值对风电并网引起的电压波动的影响，结果表明系统短路容量越大，电压波动越小，合适的线路X/R值可将电压波动降为最小。最后，分析了系统分别发生单相、两相和三相短路故障时，风电场的运行状况，得出三相短路故障最严重。 关键词：风力发电、双馈型风电机组、电压波动、故障分析 Abstract The wind energy is uncertain, and when a large scale wind power is injected into the power grid, the voltage fluctuation of the power network is caused. In this paper, the essential cause of the grid voltage fluctuation is the fluctuation of the output wind power. Taking the doubly fed wind turbine as the research object, the grid connected simulation model of the doubly fed wind turbine is built in Matlab/Simulink. Simulation and analysis of the wind turbine respectively in the constant voltage and constant power control mode of the cut after the operation characteristics and its influence on the grid voltage. The results show that constant power control with constant voltage control mode has better voltage quality. After the output of the wind farm is stable, the wind speed fluctuation and the fluctuation of the wind farm load fluctuation are analyzed. The wind speed and the load fluctuation are more serious, and the higher the voltage fluctuation of the network is. Under the random fluctuation of wind velocity, analyzes the system short circuit capacity and line X/R of grid connected wind power due to voltage fluctuations, the results show that the system short-circuit capacity is more big, the voltage fluctuation is small, suitable line X/R value of voltage fluctuations will be reduced to a minimum. At last, the operating condition of the wind farm is analyzed when the single-phase, two-phase and three-phase faults occur respectively, and the most serious of the three-phase short-c