水电高占比电网中水轮机模型对频率振荡特性影响及其适应性分析

Influence of a turbine model on frequency oscillation characteristics and its adaptability in a high hydro-ratio power grid

在小电网中,频率稳定是系统暂态稳定重点关注对象之一。水电高占比时,水轮机及其调速器模型的准确性直接影响频率稳定分析结果。针对该问题,对比分析了采用理想模型、基于运行点变化模型、传递系数模型的电网频率动态特性。通过水电机组传递函数,量化分析了不同水头高度及机组不同出力运行时的振荡频率和阻尼特性。通过暂态仿真,研究了不同模型对机组不同运行点扰动后的频率的振荡特性。最后给出了适用于工程计算的水轮机仿真模型建议。

In a small power grid,frequency stability is one of the most important issues.The hydro-turbine and its speed governor model directly affect the accuracy of frequency stability results in a high hydro-ratio power grid.To examine this issue,the frequency dynamic characteristics of a power grid using ideal,operation point change and transfer coefficient models are compared and analyzed.Based on the transfer function of hydropower units,the oscillation frequency and damping characteristics of different water head and units with different output are quantitatively analyzed.Through transient simulation,the frequency oscillation characteristics of different models at different operating points of the unit are studied.Finally,some suggestions are made for a turbine simulation model suitable for engineering calculation.