基于SCADA及PMU多时段量测信息的独立线路参数估计方法

An Approach to Estimate Parameters of Single Transmission Line Based on Multi-Interval Information Measured by SCADA and Phasor Measurement Units

基于单一线路两端的监控与数据采集系统(supervisory control and data acquisition system,SCADA)和相量采集装置(phasor measurement unit,PMU)多时段量测信息,建立了5种独立线路的约束最小二乘参数估计模型,其中,量测方程分别由线路两端有功、无功和电压幅值的SCADA量测、电流与电压相量的PMU量测以及线路两端电压相角差的PMU虚拟量测组合形成,约束方程为参数变量的上下限约束。采用Matlab的lsqnonlin优化函数求解参数估计问题,并基于多条典型线路的模拟量测信息仿真分析了所有模型的适用条件。结果表明,在负荷较重、线路较长条件下,利用所建含PMU量测的4种模型,都可以有效估计出线路的阻抗参数。

Based on multi-interval information measured by phasor measurement units （PMU） and supervisory control and data acquisition （SCADA） system located at both sides of a single transmission line, five least squares constraints optimization models for parameter estimation of single transmission line are built, in which the measurement equations are composed of following measurements： the active power, reactive power and votlage amplitude are measured by SCADA at both sides of transmission line; the phasors of votlage and current are measured by PMUs; and the phase differences of voltage and current between both sides of transmission line are virtually measured by PMUs. The constraint equationa are composed of upper and lower physical constraints of parameter variables. The parameter estimation is solved by lsqnonlin optimization function in Matlab. Based on simulated measurement information of multi typical transmission lines the applicable conditions of all built models are simulated. Simulation results show that the impedance parameters of transmission line can be effectively estimated by four of the built models, which contains PMU measurement, under heavier load and longer length of transmission line.