归一化能量函数在河南电网暂态稳定性评估中的应用

APPLICATION OF NORMALIZED ENERGY FUNCTION IN TRANSIENT STABILITY ASSESSMENT OF HENAN POWER NETWORK

介绍了归一化暂态能量函数在河南电网暂态稳定分析中的应用。通过归一化发电机转子运动方程,将故障后电力系统的动态过程比拟为在n 维欧几里得角度空间势能谷中滚动的单位质量小球。研究了故障后系统归一化暂态动能极小值与故障切除时间的关系,并在此基础上提出通 过能量平移评估暂态稳定能量裕度的思想。基于能量平移及故障后系统归一化暂态能量函数的守恒性,还提出了计算故障后系统吸收归一化动能能力的新方法。最后通过该归一化能量函数在河南省网暂态稳定评估中的应用,说明了该方法的有效性。

The application of normalized transient energy function (NTEF) in transient stability assessment of Henan power network is presented. Through the normalized gene-rators' equations of rotor motion with respect to the center of inertia of power systems, the dynamic process of post-fault power system is analogized as a rolling ball with unit mass in the normalized potential valley of an n-dimensional Euclidean angular space. The variation characteristic of the minimum of normalized transient kinetic energy (NTKE) in the post-fault duration for a contingency versus fault clearing times has been studied. Based upon the above characteristic, a novel approach named energy translation for assessment of transient stability energy margin is proposed. Based on the idea of energy translation and the conservation of NTEF, a new method to evaluate the capability absorbing the component of NTKE contributing to the system separation is developed. Applications of the method on the power network of Henan province are reported and case studies are given to show the validity of the method in transient stability assessment.