永磁直驱风电机组的风电场动态等效方法

摘要

This paper proposes a multi-machine representation method for dynamic equivalence of wind farm with permanent magnet direct-drive variable speed wind turbines considering wind speeds with non-uniform distribution. Using turbine position as a cluster classification index to group wind turbines into one equivalent wind turbine, hub speeds of wind turbines is calculated according to wake effect and spatial distribution characteristics of wind speeds. Wind turbine operating characteristics is represented by use of transfer function and the control characteristics of back-to-back PWM converter is described by current controlled current source (CCCS). A large wind farm model represented by multi equivalent wind turbines is created in EMTP/ATP software package. Case study is carried out under fault condition. Simulation results show the power output property, as well as dynamic voltage characteristics of the wind farm at the grid integration point. This work is supported by National Natural Science Foundation of China (No. 51077126 and No. 51174290).%　　针对风电场内不同机组处风速分布不均匀问题，提出了一种适用于永磁直驱变速机组风电场动态等效的多机表征方法。该方法根据机组位置进行聚类得到等效机组，结合尾流效应与自然风的空间分布特性计算等效机组轮毂高度处的风速，采用传递函数表征机组变速调节特性和电流控制电流源等效模拟双 PWM 背靠背变流器的控制特性，从而建立了大型风电场的多机动态模型。算例仿真表明，该模型能够反映风电场输出有功、无功和 PCC 点电压的动态特性。