Traveling wave based protection for medium voltage grids with distributed generation

摘要

High penetrations of distributed generation in distribution grids may cause malfunctioning of conventional protection systems due to bidirectional flows and highly variable short-circuit levels. While there has been extensive research on this topic, developing a reliable cost-efficient protection system for active distribution grids remains a challenging task. This paper presents a new protection algorithm for medium voltage lines based on Traveling Wave theory. The fault direction is determined by analyzing differential equations that describe the behavior of fault-induced current waves in the vicinity of the protection terminal. The distinction between external and internal faults is performed by classifiers based on Neural Networks. The protection algorithm uses only current measurements as inputs and does not require any information exchange, which makes it a potentially low-cost yet reliable solution. The algorithm's performance is evaluated on the IEEE 34-bus test distribution system.