自备电厂发电机励磁系统稳定性分析及控制研究

励磁系统的控制模式和控制参数对发电机及电力系统安全稳定运行有较大影响,一些厂矿企业电网的停电事故,暴露出自备电厂运行时存在励磁系统稳定问题。针对此问题,建立了计及恒无功、恒功率因数励磁控制方式的Heffron-Philips扩展模型,形成系统状态矩阵,通过特征根分析研究影响励磁系统稳定性的主要因素;基于根轨迹方法提出一种考虑系统稳定性的励磁系统控制参数优化方法。剖析了某实际厂矿企业自备电厂发电机组异常振荡现象的机理,并改进了励磁控制参数,仿真结果验证了所提方法的有效性。

Analysis and control for captive generator excitation system stability

The control mode and control parameters of excitation system exert larger influence on generator and power system safe and steady operation. Some power outage in the power grid of industrial enterprises revealed the excitation system stability problem in captive power plants. A Heffron-Philips extended model considering constant reactive power and constant power factor excitation control mode is established and system state matrix is formed. The main factors affecting excitation system stability are studied by eigenvalue analysis. A method for exciter parameters optimization is proposed based on system root locus. The abnormal oscillation phenomenon of captive generator in actual industrial enterprises power grid is analyzed and the exciter parameters is redesigned. The analysis and design approaches are verified by simulation results.