Abstract: Capacitors and DGs are commonly used in distribution system for real or reactive power compensation so that it reduces the losses, increases the maximum flow through cables and in transformers, and also improves the system power factor and voltage profile. The Reduction of losses in distribution system is very essential to improve overall efficiency of power delivery. This can be achieved by placing capacitors and DGs at different locations in radial distribution system. By considering the above advantages, in this paper to improve voltage profile and to reduce losses to increase efficiency in radial distribution system, the location and sizing of capacitors and DGs are addressed using two main factors. They are loss sensitivity factor for location and particle swarm optimization algorithm for sizing is used. To show the effectiveness, obtained results are compared each other. The proposed method is programmed and tested in a IEEE 33 bus distribution system using MATLAB software. For load flow analysis of the distribution network, Newton-Raphson method is used.

Keywords: Radial distribution system, loss sensitivity factor, PSO Algorithm, Capacitor placement, DG placement.