Electrical Engineering Department, South Tehran Branch, Islamic Azad University, Tehran, Iran.
The long-term planning of distribution network expansion planning has different complexities, because this problem has a lot of decision-making variable. The optimal placement problem of HV/MV substations with distributed generations simultaneously for supplying the capacity required for power system are analyzed in this paper. In the mathematical model, objective function together with constant, varied variables and constraints related to limitations for the operation of substations and distributed generation resources as well as network limitations are formulated. Despite of distributed generation resources, the simultaneous placement must be so that firstly load points to be supplied and secondly loss costs of the network to be reduced. In addition, the voltage profile improvement and reduction of network reconfiguration costs are considered. At the end, we will observe the power quality improvement in load points. To solve this problem, optimization of one of new algorithms named cuckoo optimization algorithm has been applied. The study period for performing this test by means of dynamic-pseudo method for a long-term study will be within the design period. Finally, tests will be provided for proving the efficiency of this offered optimization algorithm.