弱互联电网条件下水电站的水机电耦合特性及非线性振荡研究

Lower frequency oscillation happen easily in hydropower system with weak connected grid, which endangers dynamic stability and security of power system, causes hydropwer plants to reduce output power. In the project, nonlinear oscillation mechanism of complex hydropower systems with weak grid are studied. Firstly, detail hydropower station model with hydro-mechanical-electrical coupling would be done, with which stations with complex conduits and mutli-units parallel operation with long distance transmission lines to power grid can be used to study related nonlinear oscillation. Secondly,oscillation mode and associated factor of hydropower stations are studied by modal series method. Thirdly, chaotic oscillation of hydropowe stations is discussed by bifurcation theory. Finally, dynamic oscillation mechanism of complex hydropower systems would be validated by theory analysis results and numerical simulation. The study is meaningful on basic research and engineering application for dynamic oscillation study of cmoplex hydropower systems and large area interconection power grid and improving of hydro energy utilization ratio.

弱互联电网条件下水电站易引发电网侧动态振荡问题，危及系统动态安全稳定，造成水电站窝电运行，导致水电资源浪费。本项目针对水电站产生机理不明的低频振荡问题，探讨水机电耦合非线性特性激发水电站非线性振荡的机理，主要内容包括1) 建立一个水电站水机电耦合详细统一模型，研究具有复杂输水管道和多台水轮机并列的大型水电站通过弱联系长距离输电线路接入电网的动态振荡问题。2)采用模态级数法等非线性理论解析研究水电站非线性振荡模式及相关因子。3)采用混沌分岔理论研究水电站混沌振荡，研究水力参数、压力脉动对混沌振荡的影响。4）通过数值仿真验证非线性理论解析结果。这对于促进复杂水电系统乃至整个大区域互联系统的动态稳定性分析及控制问题研究，提高水电站能源利用率，具有重要的基础研究和工程应用意义。

弱互联电网条件下水电站易引发电网侧动态振荡问题，危及系统动态安全稳定，造成水电站窝电运行，导致水电资源浪费。本项目针对水电站产生机理不明的低频振荡问题，探讨水机电耦合非线性特性激发水电站非线性振荡的机理，主要内容包括1) 利用线弹性模型建立一个水电站水机电耦合详细统一模型，研究具有复杂输水管道和多台水轮机并列的大型水电站通过弱联系长距离输电线路接入电网的动态振荡问题。2)采用模态级数法等非线性理论解析研究水电站非线性振荡模式及相关因子。3)采用非线性空间变换理论研究水电站非线性振荡模式特点。4）通过数值仿真验证非线性理论解析结果。这对于促进复杂水电系统乃至整个大区域互联系统的非线性稳定性分析及控制问题研究，提高水电站能源利用率，具有重要的基础研究和工程应用意义。