An Appropriate Distributed Generation Sizing Considering Recloser-Fuse Coordination

Among various applications, this paper has applied distributed generation (DG) as backup generation when main generation supply is cut due to system equipment failure and protection operation. As backup generation, DG can certainly increase the system reliability, especially in radial distribution system, if the related concerns are deliberately taken into account. The reliability improvement can be obtained in term of the reduction of outage duration. Regarding the influential issues, protection coordination between recloser and fuses has been taken into account. This is a key factor to determine the appropriate DG size. With this consideration, the existing protection scheme of recloser and fuse can be maintained while DG has been installed. In addition, forced outage rate (FOR) of DG is included in the study. The appropriate size of DG is calculated from optimal power flow (OPF) that treats DG as another electric source in addition to utility substation. In this study, the cost function is the total electricity cost from both utility substation and DG including the outage cost from the energy not supplied (ENS). The proposed algorithm has been applied to RBTS-Bus 2, a reliability test system for electric distribution study. Simulation results confirm that the proposed algorithm provides an appropriate DG size that cope with the aforementioned concern of DG - protection coordination