基于两步分群法的双馈机组风电场等值建模

Equivalence of wind farms with DFIG based on two-step clustering method

为了在保证风机等值精度的基础上降低风电场仿真模型的复杂度,考虑到实际风电场内尾流效应及风机控制方式不同的情况,借鉴层次分析法的思想提出了两步分群法。该方法综合考虑了风机初始运行点以及动态特性。首先考虑风电机组间尾流效应计算输入风速,根据机组桨距角动作情况进行初次分群,通过转子电流受扰曲线识别动态特性相近的风机实现再次分群。然后在保证风电机组功率输出特性和电压差恒定的基础上,进行风机和集电线路参数等值,得到风电场多机等值模型。最后通过仿真验证了所述方法的合理性。

In order to reduce complexity of simulation model of wind farm while ensuring accuracy, and considering wake effect and different control methods in actual wind farm, a two-step clustering method based on Analytic Hierarchy Process is proposed. Both initial operating point and dynamic behavior are considered in this method. Firstly, the input wind speed is calculated under the influence of wake effect. The first step clusters the DFIGs according to pitch angle action situation, and the second step re-clusters the DFIGs by their dynamic characteristics according to disturbed curves of rotor current. Then parameters of equivalent wind turbine generators and collecting power lines are derived respectively to ensure power output characteristics and voltage difference constant. Thus a multi-machine equivalent model of wind farm is obtained. Finally the proposed equivalent method is validated by simulation results.