Distribution network expansion considering distributed generation and storage units using modified PSO algorithm

•We consider HV/MV substations, main and reserve feeders, DG and storage units for multistage distribution network planning.•DG and storage units are used for both peak cutting and reliability improvement.•DG and storage units are operated regarding proposed strategies.•A modified particle swarm optimization algorithm is proposed to solve the problem.

Multistage distribution network expansion because of load growth is a complex problem in distribution planning. The problem includes minimizing cost of objective function subject to technical constraints. The objective function consists of investment, operation and reliability costs. In this paper, HV/MV substations, main and reserve MV feeders, dispatchable DG sources and storage units are considered as possible solutions for multistage distribution expansion planning. A three-load level is used for variable load and some strategies are proposed for DG and storage units operation. A modified PSO algorithm is applied to solve the complex optimization problem. Numerical results of the case studies show the ability of the modification. Moreover, the proposed strategies improve the distribution network from both economical and reliability points of view compared with the other methods.