A hybrid optimization method for distribution network operation with SNOP and tie switch

Soft normally open point (SNOP) refers to a novel type power electronic device installed in place of a normally-open point, also called tie switch, in a medium-voltage distribution network. The application of SNOP will greatly promote the flexibility and controllability of the distribution network. Considering the higher investment and operation cost of SNOP, both tie switch and SNOP should be taken into account as a whole in the operation optimization problem of distribution system in the future. Firstly, the time-series optimization model of distribution network operation with SNOP and tie switch was proposed, which belongs to a mixed integer nonlinear problem. Secondly, combining the simulated annealing method with the conic programming, this paper proposed a hybrid optimization algorithm, which used simulated annealing method to solve the switch states and conic programming to solve the power of SNOP. The hybrid optimization algorithm can solve large-scale mixed-integer nonlinear optimization problem accurately and rapidly, which also satisfies the demand of time-series optimization problems. Finally, the optimization model and the hybrid optimization algorithm were analyzed and verified on IEEE 33-node test feeder.