基于多分支电流混合量测的配电网三相状态估计

Three-phase state estimation of a distribution network based on multi-branch current mixing measurement

同步相量测量应用于配电网高级应用中是近年来的研究热点。针对配电网同步相量与智能电表的混合量测问题,提出一种以支路电流为状态变量的配电网状态估计方法。该方法在含分布式光伏接入的配电网中,将微型同步相量测量单元(Micro-Synchronous Phasor Measurement Unit,μPMU)和智能电表量测数据进行等效变换,实现异构数据支路电流幅值量测误差最小。首先,基于混合量测系统,推导三相量测方程模型。然后,运用加权最小二乘法实现了三相支路电流的状态估计。所提方法适用于三相不平衡、多分支电流量测的配电网。最后,通过对含分布式光伏的IEEE 37节点系统进行仿真,验证了方法的有效性。

Synchronous phasor measurement is a research hot-spot in advanced application to a distribution network.Examining hybrid measurement of a synchronous phasor and smart meter in a distribution network,this paper proposes a state estimation method for the distribution network with branch current as the state variable.In a distribution network with distributed photovoltaic access,the method transforms theμPMU and the smart meter measurement data,and realizes the minimum measurement error of the heterogeneous data branch current amplitude.First,based on the hybrid measurement system,the three-phase measurement equation model is derived.Then,the state estimation of the three-phase branch current is realized by weighted least squares method.The proposed method is applicable to the distribution network of three-phase unbalanced and multi-branch current measurement.Finally,the effectiveness of the method is verified by simulating the IEEE 37-node system with distributed photovoltaics.