Multiperiod shunt capacitor allocation in radial distribution systems

Abstract

In distribution systems, low power factor is a common problem due to inductive nature of the loads. To overcome this problem, generally capacitors are installed on distribution systems. In this paper, to maintain the voltage profile, a dynamic model considering multiperiod capacitor allocation problem of primary radial distribution system is proposed. The model incorporates the load growth rate, load factor and cost of power and energy losses. This multiperiod optimization problem is solved using a population based swarm method i.e. ACS for minimizing the total cost of the peak power losses and energy losses and cost of capacitor installation from base to horizon year (for the feasible options at each planning year) subject to constraints corresponding to upper and lower bounds of the voltage magnitude at each bus. The feasible set of options for optimal capacitor site and size placement in each single stage problem is obtained using particle swarm optimization To reduce the computational efforts in each stage, the candidate nodes for placing capacitors in distribution system are determined by calculating change in real power losses with respect to reactive power injection at the buses. The proposed approach has been implemented on 69-bus test system.