A New Directional Algorithm-based Approach to Fault Localization for Distribution Networks with High Penetration of Photovoltaic Systems

Traditional fault location and isolation system in French distribution network uses nondirectional overcurrent based fault locators and remotely controlled switches. Although statistics have proved its effectiveness, the rising integration of distributed energy resources has considerably challenged the reliability of this system. The objective of this research is to develop a new directional algorithm that can be integrated into the existing fault indicators in order to address issues related to the connection of new distributed generations. The algorithm uses the phase angle of the prefault voltage as reference quantity and that of the negative sequence current as operating quantity. The proposed technique is then deployed to develop a new fault location and isolation scheme. In order to evaluate the effectiveness of the proposed scheme, a Control-Hardware-In-the-Loop simulation platform which is based on OPAL/RT simulator and ARM -based computers has been built.

I. Introduction

Currently in France, Remotely Controlled Switches (RCS) with integrated Fault Indicators (FI) are used for locating faults in distribution networks [1]. If a fault occurs in the network beyond the FI location, it can detect and forward information about the fault to substation control center. In case of a permanent fault, recloser will open after a few unsuccessful reclosing. Prior to reconnection of the disconnected feeder, the fault should be isolated. This can be done within several minutes by utility operator who, with an assistance of a dedicated SCADA system, can remotely open two RCSs directly connected to the fault point [1]. Power supply is restored to the affected customers. However, those customers between the two recently opened RCSs still suffer from the outage. Hence, a line crew then should be sent to the field in order to clear the roots of the fault, restoring power supply to the remaining customers. On the other hand, in case of a temporary fault, an accurate and speedy fault location and isolation (FLI) system can help operator quickly deal with the causes of faults, preventing these faults from happening again. Thus, FLI system plays a vital role in the outage management system, assisting in improving the SAIDI (System Average Interruption Duration Index) of the utility networks.