International Journal of Applied Power Engineering (IJAPE) Vol. 12, No. 1, March 2023, pp. 71~82 ISSN: 2252-8792, DOI: 10.11591/ijape.v12.i1.pp71-82  71 Journal homepage: http://ijape.iaescore.com Optimal capacitor allocation for minimizing cost of energy loss in active distribution network with different load levels Mya Myintzu 1 , Kyaw Myo Lin 1,2 , Khine Zin Oo 1 1 Power System Research Unit, Department of Electrical Power Engineering, Mandalay Technological University, Mandalay, Myanmar 2 Department of Electrical Power Engineering, Pyay Technological University, Pyay, Myanmar Article Info ABSTRACT Article history: Received Oct 14, 2022 Revised Dec 3, 2022 Accepted Dec 15, 2022 This paper proposes an effective technique to allocate a shunt capacitor using a meta-heuristic optimization-approach for minimizing the cost of energy losses. Particle swarm optimization (PSO) algorithm incorporated with MATPOWER is trained for minimizing the targeted function of the optical capacitor placement problem. The 115-node active distribution network supplied by MESC in the Mandalay distribution area is applied as a scenario. The results including active power loss and system energy loss, size and location of the optimized capacitor, voltage profiles, and the cost of energy loss are attained and analyzed. The simulations results revealed that the optimal allocation of the capacitor provides a significant reduction in the cost of energy losses as well as improvement in voltage profile with compensation of reactive power. Keywords: Cost of energy loss Load levels OCP PSO algorithm Voltage profile improvement This is an open access article under the CC BY-SA license. Corresponding Author: Kyaw Myo Lin Power System Research Unit, Mandalay Technological University Patheingyi, 05072, Mandalay, Myanmar Email: kyawmyolin.ep@ptu.edu.mm 1. INTRODUCTION The shunt capacitor installation in a radial power distribution system has become significant research in power system planning. For advancing power flow control and enhancement of power factor, managing voltage profile, reducing active power loss and energy loss in the network, the shunt capacitor injection on the radial feeder is presently applied. In that case, it is necessary to consider economic criteria in the installation of the capacitor to get the best design procedure. Dealing with the optimal capacitor placement (OCP) problem and sizing in the radial distribution network, many algorithms and techniques are addressed [1]–[4]. In literature, different researchers have introduced different methods considering different fitness functions including minimization of power losses, reduction in installation cost, and improvement in voltage profile, lessen the burden on existing lines as well as maximizing system stability, and others. In earlier stages, the researchers proposed the analytical procedures [5], [6] because of the computing burdens and lack of resources. After that, numerical programming [7], heuristics techniques [8], and artificial intelligent methods [9] have been progressed in OCP research. Because of making a high- quality solution within short calculation-time and stable convergence characteristics, particle swarm optimization (PSO) approaches [10] have been employed on capacitor installation research in distribution networks. The [7]–[10], the major focus is on the minimum power losses of the system and the improvement of the bus voltage regulation. From the literature review, it is observed that the application of the PSO algorithm targeting with the cost of energy loss, evaluating with daily load curves, has not been discovered in previous work. Besides, the