同步发电机不同实用模型的大扰动特性对比研究

Comparison of Large Disturbance Characteristics of Different Generator Practical Models

为了研究同步发电机3种实用模型对电力系统大扰动特性和暂态稳定极限的影响,采用dq0坐标系下的实用模型与abc坐标系下的电网模型联立求解的方法,推导了发电机与电网接口关系的方程,建立了以实用模型为基础的单机双回线无穷大系统,并以经过试验验证的场路网耦合时步有限元模型作为标准响应,对各实用模型进行校验。采用上述模型对300 MW同步发电机进行仿真计算表明:3种实用模型的大扰动特性存在明显差异,且暂态稳定极限都较为保守;额定励磁下,实用模型与时步有限元的暂态稳定极限最大相差8.8%。研究结果为电力系统仿真中合理选择发电机模型提供了重要参考。

In order to research the accuracy of the practical models on large disturbance and transient stability limit, the relation equations between generator and power grid were deduced particularly adopting method of dqO coordinate system and abc coordinate system coupled, then single-machine infinite system based on practical models was established. At the same time, the time step finite element method （T-S FEM） which was checked by test would be a standard to verify the practical models. On that basis, large disturbance and transient stability limit of 300 MW synchronous generator were simulated and calculated through practical models and T-S FEM. The result indicated that the large disturbance characteristics among three practical were different; the transient stability limits calculated by practical models were conservative, the maximum deviation was 8.8%. The result provides reasonable reference to select practical model in power system simulation.