EMTP modeling of protective devices for distribution systems with distributed generation

The impact of distributed generation (DG) in a distribution network depends on the design of the protection system and the coordination between the different protective devices. This paper presents the main features of a library of protective devices implemented in an EMTP-type tool for power quality studies in distribution networks with distributed generation. The document discusses the present protection practices for DG interties, describes the characteristics of the new protective devices, and includes some simple case studies whose main goal is to analyze the performance of the protective devices and the coordination between the various types of protective devices taking into account the impact of embedded generators.