Wind turbine generators can be operated in various types of system configurations. Once the configurations change, the system oscillation mode shapes change accordingly. The modelling of the full system is necessary for studying this issue, yet it is quite hard. In this paper, a simple approach is developed to study the mode shapes of wind power systems without the necessity of adopting the complex full-system models. The key is that the q-d axis model of electric power system is transformed into the single-axis model, so that it could integrate with the equivalent circuit model of drive train mechanism. After analyzing some of the system configurations organized by the well-known MOD-2 wind turbine generator unit, the proposed approach is found to be effective for analyzing various oscillation modes such as the local torsional oscillations, as well as the inter-unit and inter-area oscillations.

中文翻译：

---

风力发电系统振荡模式的简化建模

风力涡轮发电机可以在各种类型的系统配置中运行。一旦配置更改，系统振荡模式形状也会相应更改。完整系统的建模对于研究此问题是必要的，但相当困难。本文提出了一种简单的方法来研究风力发电系统的模式形状，而无需采用复杂的完整系统模型。关键是将电力系统的qd轴模型转换为单轴模型，以便与动力传动系统的等效电路模型集成。在分析了由著名的MOD-2风力发电机组组成的一些系统配置后，发现该方法对于分析各种振动模式（例如局部扭转振动）是有效的。