电压稳定临界域的描述及在线近似确定

The critical domain description of voltage stability of power system and its dertermination

广域测量技术的发展和应用为电力系统电压稳定监视奠定了基础。在此引入负荷阻抗角建立了新的电压稳定临界域的描述即电压表示形式和功率表示形式,并建立了电压稳定域。利用广域测量技术对节点戴维南等值参数的在线估计实现了对静态电压稳定临界域的在线确定,间接地避免了潮流计算中Jacobi矩阵在临界点奇异而带来的不收敛问题,弥补了传统方法在线应用中存在的系统规模大、非线性模型不准确、数据多且更新不及时、速度慢等缺陷。通过仿真计算表明提出的方法可行,可在线快速确定电压稳定临界域。

The development and applications of wide-area measurement system （WAMS） established the foundation of on-line assessment of voltage stability in large-scale power system. This paper presents a new description of the voltage critical states-the voltage expression and the power expression, and the voltage stability domain is established. The critical domain of voltage stability is determined through the estimation of the Thevenin＇s parameters of a node. Through the local measurement, the method can indirectly avoid the divergence problem caused by the Jacobian matrix singularity of load flow at the critical state. And it avoids the limitations of the conventional methods in on-line applications such as the large-scale power system, the nonlinear model inaccuracy, slow updating of large amount of data. Simulation results prove the proposed method reasonable and that it can on-line determine the critical domain of the node static voltage stability.