基于零阻抗支路模型的变电站三相非线性状态估计方法

Zero Impedance Branch Based Substation Three-phase Nonlinear State Estimation Method

为了将拓扑和量测错误解决于变电站内,提高调度中心状态估计的可靠性和精度,提出一种基于零阻抗支路的变电站三相非线性状态估计方法。该方法充分利用了变电站内冗余的多源量测数据,包括远方终端单元(remote terminalunit,RTU)和相量量测单元(phasor measurement unit,PMU)的三相量测数据,基于基尔霍夫电流定律(Kirchoff’s currentlaw,KCL)建立了面向开关的非线性三相零阻抗状态估计模型,实现了模拟量坏数据和拓扑错误的解耦辨识以及对三相不平衡度的实时监控,具有高冗余、估计结果可靠、计算速度快和易于实现等特点。算例分析验证了方法的有效性。

A substation three-phase nonlinear state estimation method based on zero impedance branches is presented in order to eliminate topology and analogy errors at substation level and accordingly enhance the control center state estimation reliability and accuracy. Measurements from different apparatus are utilized in substation, such as remote terminal unit （RTU） and phasor measurement unit （PMIJ） three-phase data. A breaker-oriented nonlinear three-phase state estimation model is established on Kirchoff＇s current law （KCL）, in which analog bad data and topology bad error identification can be decoupled, realizing real-time three-phase unbalanced degree monitoring at substation level. It is shown that this method is very fast and easy for implementation and can provide high measurement redundancy and reliable results. The test results show that the proposed approach is very effective.