DISTRIBUTED GENERATION PLANNING USING DG WITH REACTIVE POWER CAPABILITY

Abstract

The share of distributed generators (DGs) in power systems has been slowly increasing in the last few years. As the penetration of DG in distribution system increases, it is in the best interest of all players involved to allocate DG in an optimal way such that it will reduce system losses and hence improve voltage profile. However to achieve these objectives we should keep in mind the overall economy also. Inappropriate selection of location and size of DG. may lead to greater system losses than the losses without DG. Hence it is of vital importance to find the optimum location and size of DG during the planning. This thesis involves calculation of optimal size and corresponding optimum location for DG placement for minimizing the total power losses and cost in primary distribution systems. 1-lere loss sensitivity method is used to find the optimum location and particle swarm optimization algorithm is used to find the optimum size of DG. The integration of renewable DG units such as wind and solar PV based units further support the DS while possibly reducing fuel cost associated with fuel based DG units. But the integration of non-dispatchable renewable DG units cannot guarantee fixed power output due to uncertainties in power availability (such as wind speed, solar radiation etc.). Most of the existing works on the distribution system planning with DG have considered DG as purely active power sources. But the reactive power taken from DG units can help to improve voltage profile and to reduce energy loss. Hence in this thesis, reactive power capability limits of DGs are considered. The traditional works in this planning problem calculate the energy loss based on the peak load demand only. This is not quite right. Hence the uncertainty in the load demand is taken into consideration in this thesis based on probability distribution function.