Management of Distribution System Protection with High Penetration of DGs

Abstract

As a result of deregulation and emerging distributed generation (DG) in distribution networks, some protection problems and challenges emerge which need immediate solutions by design engineering. The present generation of numerical protection relays allows the implementation of adaptive settings for distribution system protection especially with systems of a high penetration of DG. This chapter presents an overview of the use of communication infrastructure to improve some aspects of distribution system protection, especially adaptive protection. One of the key issues has been to verify that traditional network protection schemes and set-tings are simply not adequate when there are DG systems connected to the network. The impact of the DG unit increases with the size of the generator and with the length of the line section between the DG unit and the fault. Results have provided a clear indication of the potential protection problems that need to be solved by careful protection design. Some solutions have been proposed in this chapter through communication and intelligent electronic devices (IEDs) based on power system simulation studies using ETAP software. The results will be used to focus further research and development in protection systems and concepts. 27.1 Introduction In the last decades, electrical power systems (EPS) have enlarged to meet the growing demand for electrical power. After deregulation, EPS also become more intercon-nected and difficult to operate, which increases competition among agents. Thus, the