PSASP-based City Grid Ring-Closing Strategy Research and Corresponding Risk Assessment

In the actual 110 kV substations operation mode, the implement of the sectionalizing in urban power network in China occurs ‘boundary substations’ phenomenon. With the further deepening of the sectionalizing, increasing boundary substations are going to have an unignorably impact on the quality of power supply in the urban grid. A strategy to limit the power flow during ring-closing operation without power cut based on load-transfer is proposed in this paper which starts with the theoretical analysis of the power system. In addition, through the simulation calculation of PSASP (the power system integrated program), a corresponding risk assessment tool has been set up to simulate and evaluate the risk of this ring-closing strategy towards boundary substation, which further reduce the risk during ring-closing operation. Furthermore, this strategy has been verified in the power grid plan of some city through the risk assessment tool.