Study on coordination of protective relays in distribution system with distributed generation

摘要

In the recent decade, many countries around the globe have been increased the proportion of electrical power generation from renewable energy sources, which results in rising in the penetration level of distributed generation (DG). However, the installation of DG into the distribution system may raise many issues that can impact the distribution system in both the technical and economic aspects. When DG is connected to a distribution system, it can affect the performance of the system and the protective device already installed owing to the change of voltage level, short-circuit level and direction of power flow in the system. For this reason, a protective device may cause the malfunction because the bus impedance of the system is changed; this will result in a change of the current in each bus. This paper aims to study the coordination between the protective relay and the DG installed into the distribution system. The distribution system under investigation is a part of the Provincial Electricity Authority (PEA). Under this research, DG data that are connected to the PEA distribution is used. The simulations are performed using digital simulation and electrical network calculation program (DIgSILENT).