三相不平衡下交直流配电网状态估计

State Estimation for Three-phase Unbalanced AC/DC Distribution Network

基于电压源型换流器(VSC)的柔性直流技术被越来越多地运用到配电网中,需要对含VSC的三相不平衡交直流配电网进行准确的状态估计,而配置相量测量单元(PMU)的测量数据是实现配电网准确状态估计的有效手段。首先,提出了考虑配电网三相不平衡特性的交直流配电网状态估计模型,采用加权最小绝对值法进行状态估计;其次,进行PMU测量数据的线性描述,给出了PMU及数据采集与监控(SCADA)系统的混合测量方程,并将多种交直流设备在测量方程中统一描述;最后,在三相不平衡的IEEE 33节点交直流配电网算例上,验证了所提方法的有效性和实用性。

Flexible DC technology based on voltage source converter(VSC) is increasingly applied in distribution networks. Accurate static state estimation of the three-phase unbalanced AC/DC distribution network with VSC is needed. An effective way to achieve accurate state estimation of distribution network is to configure measurement data of phasor measurement unit(PMU). Firstly, the state estimation model of AC/DC distribution network considering the three-phase unbalanced characteristics of distribution network is proposed. The weighted least absolute value method is used for the state estimation. Secondly, the linear description of PMU measurement is given. In addition, the hybrid measurement equations of PMU and supervisory control and data acquisition(SCADA) with various AC/DC devices are uniformly given. Finally, the effectiveness and practicality of the proposed method are verified on the three-phase unbalanced IEEE 33-bus AC/DC distribution network.