A FLISR approach for distribution networks integrated distributed generators

Abstract

The penetration of distributed generators (DG ) into the distribution etworks (DN) greatly improves the reliability of electricity supply and reduces power loss. However, the operation of these DGs can also make the protection of distribution etwork more complex. This paper will examine the effects of two DG types on the protection of DN by analyzing the solution called Fault Location, Isolation and Service Restoration (FLISR). The FLISR approach considers DGs as auxiliary sources for the post-fault restoration plans in order to minimize the number of interrupted customers and unserved energy. Moreover, the combination of setting value of the overcurrent relay and the statuses of switching device and the loss voltage warning signal are used to detect and identify types of incidents in the distribution etwork with DGs. A two-constrained objective function will be solved to find possible plans for fault isolation and service restoration. There are six performance indices (PIs) selected for post-fault service restoration processing. The simulation results for the 22kV distribution network with integrated DG were performed by using E-terra software to validate this FLISR approach. To be concluded, the FLISR approach well adapt to the integration of DG into the DN and also helps to identify risks from false protection-coordination. On the other hand, it also helps to quickly detect and identify types of incidents as well as evaluate service restoration plans after incidents of distribution etwork with DG less than two minutes.