Impact of voltage dip and protection system operation on electrical distribution system reliability

Abstract

This thesis presents the impact of voltage dip and protection system operation on electrical distribution system reliability. There are two parts of analysis in this thesis. The first part concerns the impact analysis of protective devices on system reliability. In general, using protective devices on the system e.g. Fuses, disconnecting switches, and recloser can help the system its reliability improves. The analysis will be done based on three cases of protection scheme, i.e. fuses as lateral protection, fuses and disconnecting switches, and fuse-recloser coordination. It will be shown in this thesis that all of these schemes have great impact on system reliability, a large amount of energy can be saved, and a number of interruptions can be avoided.The second part concerns the analysis of the impact of voltage dip on system reliability. In the first analysis, it can be known that using protective devices can system reliability improve. In that case, it is just assumed that all the remaining customers can with stand the voltage dip. However, in practice, some customers can not tolerate the voltage dip, and they will be cut off from the supply. Therefore, the impact of voltage dip on customer interruptions should not be neglected and have to be taken into account. This thesis shows that the impact of the voltage dip worsen system reliability. In this thesis, the developed methods based on an analytical method will be test with the Reliability Test System (RBTS). Satisfactory results are obtained.