Single-Loop Optimization for Losses Minimization in Medium-Voltage Power Distribution System

One important goal during the reconfiguration of a medium-voltage power distribution network is to minimize the active-power losses of the system. Therefore, the objective function of an optimization problem would represent the total power losses of the distribution system, by considering only the active component of power losses while ignoring the reactive part. Constraints would be load flow, voltage drop, and the network configuration. In this paper, losses problem during the reconfiguration of a medium-voltage power distribution system have been minimized using a single-loop optimization method, whereas the load-flow analysis has been performed by utilizing the Newton-Raphson method. The optimization method was aimed to minimize the active-power losses of the system by formulating the problem as a matter of network reconfiguration. The solution scheme has been begun with a mesh distribution-network which had been obtained previously by assuming all the switches to be closed and then opened sequentially to eliminate loops. The optimization results showed that in a 21-bus distribution system there had been 10800 combinations, in which the lowest power losses occurred under the combination of NO 23, NO 21, NO 22, NO 24, NO 25, whereas the combination of NO 7, NO 10, NO 20, NO 15, NO 20, resulted in the power losses of 0.1676 per unit, being equal to 16.76 kVA at the base power of 100 kVA.