大容量风电场接入后电网电压稳定性的计算分析与控制策略

由于风电场容量较大，并位于电网末端，可能会对电网的电压稳定性产生较大的影响。为保证风电场投入后的安全，按大干扰下风功率的转换特性及异步发电机的运行特性建立了风电场与相关电网的数学模型，计算了风电场与相关电网发生短路故障后的电压稳定性。通过数值仿真计算，揭示了风电场接入导致电网电压稳定性被破坏的机理，指出机组转速是影响风力机和异步发电机这两个能量转换器工作特性的关键参数，控制风电场内风机的速度增量是保持大容量风电场接入后电压稳定性的关键，靠近故障点的风电单元容量、故障点位置和故障持续时间是影响短路后电压稳定性的主要因素，并提出了大容量风电场接入后保证电网电压稳定性的策略与措施。

Calculation Analysis and Control Strategy for Voltage Stability of Power Grid with Large Capacity Wind Farm Interconnected

Large-scale wind farms located at the end of power grid will probably greatly impact the voltage stability of power grid. To ensure the secure operation of wind farms, according to the conversion character of wind power and operation performance of asynchronous generators a mathematical model for wind farm and related power gird under large disturbance is built, and the voltage stability of wind farm and related power grid is calculated while short-circuit fault occurs. By means of numerical simulation, the mechanism of power grid stability failure due to connecting wind farm with it is revealed. It is pointed out that the revolution speed of wind turbine generation unit is the principal parameter to impact the operating characteristics of the two energy converters, i.e., wind turbine and asynchronous generator, so the control of revolution speed increment of wind turbine is the key problem in order to maintain power grid voltage stability after large-scale wind farm is connected with power grid. The capacity of wind turbine generation unit near the faulty location, the position of faulty point and the duration of the fault are the main factors impacting voltage stability after the short-circuit fault occurs. The strategy and measures to ensure the voltage stability of power with wind farm connected are proposed.