Direct power flow algorithm for three-phase unbalanced island microgrid considering distributed power generation droop control and load static characteristics

Based on DG(Distributed power Generation) droop control,load static characteristics and three-phase unbalanced network model,a direct power flow algorithm for three-phase unbalanced island microgrid is proposed. Firstly,based on the direct power flow algorithm of distribution network,considering the influence of DG droop control and load static characteristics,a calculation model of direct power flow algorithm for three-phase unbalanced island microgrid is derived. In order to solve the calculation model of the proposed direct power flow algorithm,a two-layer power flow iteration method is proposed. The inner power flow iteration method is used to solve the power flow calculation of the three-phase unbalanced island microgrid beside the virtual node,and the outer power flow iteration method is used to update the voltage and system angular frequency of the virtual node. Finally,multi scenario simulation analysis is carried out based on Australian real network and 25-bus typical microgrid respectively,and compared with Newton trust region method. The simulative and comparison results show that the proposed algorithm can quickly and accurately reflect the characteristics and real operation state of microgrid,and can solve the power flow calculation problem of three-phase unbalanced island microgrid. © 2020, Electric Power Automation Equipment Press. All right reserved.