【作者】 孙伟；

【导师】 吴杰；

【作者基本信息】 燕山大学 ， 电力系统及其自动化， 2012， 硕士

【摘要】 近年来我国风电事业取得了突飞猛进的发展。然而，随着风力发电机组单机容量和风电场规模的不断扩大，风电对电网产生的不利影响也越来越明显。其中，并网运行风电场的电压稳定性问题受到了人们的普遍关注。本文在现有文献的基础上，结合国家电网对并网运行风电场的具体要求，对应用静止同步补偿器(StaticSynchronous Compensator, STATCOM)改善恒速恒频风电机组的暂态稳定域度和低电压穿越(Low Voltage Ride Through, LVRT)能力进行了分析和研究，并通过仿真实验验证了应用STATCOM提高风电场电压稳定性和并网运行能力的可行性。首先，本文采用四分量法建立了风速模型，对风力机各个部分建立了简化模型，理论推导出了异步发电机的稳态模型，并对异步发电机在同步旋转坐标系下的状态方程进行了推导，建立了异步发电机的三阶数学模型。其次，建立了STATCOM稳态、暂态数学模型，对STATCOM的控制策略进行了对比分析，并搭建了采用电流直接控制的STATCOM仿真模型。再次，分析了恒速恒频风电机组的静态、暂态电压稳定性，通过仿真实验对风电机组在风速变化下的机电暂态过程进行了研究，指出了风电场在电压稳定性方面存在的不足，然后对STATCOM应用于风电场的可行性进行了理论分析。最后，通过分析风电场的具体状况，设计了STATCOM的安装容量、主电路和逆变器的主要参数。在MATLAB中建立了包含风电场和STATCOM的电力系统仿真模型，在风速突变和电网故障两种典型状况下进行了仿真计算分析。仿真结果表明：大扰动发生时和扰动后，STATCOM均可迅速为风电场提供必要的无功支撑，帮助风电机组重建机端电压，抑制电网电压不断跌落和发电机转子过快加速，为风力机桨距角的参与调节赢得了时间。总之，在风电场安装合适的STATCOM可以改善风电机组的暂态稳定域度和LVRT能力，从而提高并网运行风电场的电压稳定性。更多还原

【Abstract】 In recent years, China’s wind power industry has made rapid development. However,with the continuous expansion of wind turbine unit capacity and wind farms, the adverseeffects of wind power on power grid have become more and more significant. Amongthem, the voltage stability problem of grid-connected running wind farms is causing awidespread concern. On the basis of the existing literatures and combining with thespecific requirements of state grid to grid-connected running wind farms, this thesisanalysed and researched that application of STATCOM to enhance the transient stabilitymargin and LVRT capability of fixed speed wind turbine generators, and throughsimulation experiments verified the feasibility of using STATCOM to improve the voltagestability and continuous running ability of grid-connected wind farms.First of all, this paper used a four-component method to establish the wind speedmodel, then building simplified mathematical models of various parts of the wind turbine.Through theoretical derivation, a steady-state model of the induction generator is obtained.The state equation of induction generator is also deduced in the synchronous rotatingcoordinate system, after that establishing the three-order mathematical model of theinduction generator. Secondly, building the steady-state and transient mathematical modelof STATCOM, analysing the control strategies of STATCOM and building a current directcontrolled STATCOM simulation model. Thirdly, analysis of the static and transientvoltage stability of fixed speed wind turbine generators. Electromechanical transientprocess of wind turbine generator in the wind speed changes has been studied throughsimulation experiments. Pointing out the shortcomings of fixed speed wind farms in thearea of voltage stability and theoretically analyzing the feasibility of STATCOM applied towind farms. Finally, according to analyzing the specifics of the wind farm, designing theinstalled capacity, main circuit of the STATCOM and main parameters of the inverter.Establishing the power system simulation model containing wind farm and STATCOM inMATLAB, and simulation calculation and analysis are carried out in two typicalconditions, wind speed mutations and power grid faults. Simulation results show that STATCOM provides reactive power quickly for the wind farm during and after largedisturbances, helps wind turbine generators to rebuilt terminal voltage, restrains the gridvoltage continuous drop and generator rotor acceleration, and wins time for pitch angleadjustment of the wind turbine. In a word, installing a appropriate STATCOM in the windfarm can enhance the transient stability Margin and LVRT capability of wind turbinegenerators, which improves the voltage stability of the grid-connected running windfarms.更多还原