电力系统电压稳定性及其研究现状(一)

Power system voltage stability and its present investigation(Ⅰ)

分2部分综述了电力系统电压稳定性的研究现状。第1部分首先介绍了电压稳定的定义和分类情况,然后对迄今为止电压稳定的静态和动态分析方法进行了总结和评述。静态分析方法中,灵敏度法物理概念简单明确,在简单系统中判据严格、准确,但推广到复杂系统后有效性无法保证;潮流多解法间接克服了潮流方程雅可比矩阵在临界点奇异带来的收敛问题,但低电压解的求取比较困难,现已较少采用;奇异值(特征值)分析法中潮流雅可比矩阵的奇异值或特征值变化缓慢且具有高度非线性,发电机无功越限时会导致最小特征值跳变,因而最小奇异值难以对系统电压稳定程度作出客观评价。动态分析方法中,小扰动分析法需要恰当考虑元件动态特性,建立尽可能简化而又能较精确反映系统动态的分析模型;关于分岔及混沌的理论研究一般局限于低维、简单模型系统和周期性小扰动,并引入了很多假设;基于本地测量数据的方法间接考虑了元件的动态特性,但只能用于单个节点或母线上,可作为集中控制方案的补充。

This is the first part of summary of voltage stability investigation in power systems. In this part,the definition and classification of voltage stability are first introduced and then static and dynamic analysis methods are reviewed. In static analysis methods,the sensitivity method has clear physical conception and it is strict and precise in simple systems ,but the validity could not be ensured in large systems. The multiple load flow solution method has good convergence characteristics even at the singular point of the Jacobian matrix,but now it is seldom used because of difficulties in the low voltage solution calculation. In the eigenvalue analysis method,the eigenvalue of the Jacobian matrix varies slowly with strong nonlinearity, moreover, the minimum eigenvalue will jump when the generator reactive power output exceeds the limitation,so it can＇t evaluate the system voltage stability reasonably. In dynamic analysis methods, the small disturbance analysis method requires the proper consideration of the component dynamic characteristic and the appropriate analysis model,which is simple as possible and precise at the same time. The application of the bifurcation and chaos theory analysis is limited to the periodic small disturbance and the low-dimension system with the simple model under many assumptions. The locally-measured-data-based analysis method indirectly considers the dynamic of system components, but it can only be used in the single bus. It can be complement of the concentrate control scheme.