The Research on the Partitioning Optimization Strategy of 220kV Power Grid Under Accident or Maintenance Condition

With the expansion of urban power grid, short circuit current issue becomes increasingly severe. Thus, grid partition has been applied to transmission system in many big cities. Based on a typical partitioning configuration that each 220kV partition is supplied by a single 500kV substation, a partitioning optimization strategy under accident or maintenance circumstance is proposed in this paper. To establish the optimization model, the minimum load shedding is used as an objective function. Many constraints also have been taken into consideration, including capacity limit, power flow, short circuit current, load shedding, and etc. This paper introduced an improved genetic algorithm to acquire an optimal operation solution. In order to avoid infeasible solutions and reduce computational complexity, all the possible switching combinations of each channel are listed in advance, and then each connecting channel is coded as a whole. Furthermore, two separate partitions can be connected through incidence matrix under accident or maintenance condition. Finally, the paper takes an actual urban grid as an example, which verifies the correctness and effectiveness of the theory. It contributes to a strong theoretical and technical support for grid operation and network planning in reality.