基于广域测量的在线电压稳定监视

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。对采用局部电压、电流变化估计电网侧等值阻抗进行了分析,指出利用SCADA/EMS测量数据不能准确估计电网侧等值阻抗的缺陷,提出基于节点电压和负荷电流相量变化的改进方法和电压稳定性指标。采用广域测量系统间接地避免潮流方程在临界点的不收敛,弥补传统方法在应用中存在的系统规模过大、非线性模型不准确、数据多且更新不及时、速度慢等缺陷。通过仿真计算表明该指标能够正确指示节点的电压稳定性,适于对节点在线静态电压稳定的监视,具有一定实用性。

On-line assessment of voltage stability of power system based on wide-area measurement system

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.The network equivalent impedance (NEI) estimation of using local voltage and current increment is discussed,and the estimation inaccuracy of using data of SCADE/EMS is indicated.The improvement and indices of voltage stability are proposed using the nodal voltage and load current vector's measurement.Using WAMS,the method can indirectly solve 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 show that the proposed method can make an accurate estimation of NEI,and it is applicable to on-line assessment of the node static voltage stability.