Coordination of Directional Overcurrent Protection Relay for Distribution Network With Embedded DG

Distributed Generations (DGs) are small power sources in distribution network to provide reliable and economic to residential areas or suburb areas. The relay protection has an important role to protect a power system from different faults. Coordination of relay protection minimizes the operating time of relays and prevents mal-operation.The Directional Overcurrent Relays (DOR) are used for the protection of the radial distribution network with embedded DG. This paper presents coordination of the directional overcurrent taking into account faults in different places of the power system. The setting of directional overcurrent relay has two parts, i.e., an overcurrent relay and directional element. The coordination of overcurrent relay is based on the operation of relay and time-current characteristic curve.The case study is based on a real distribution network that consists of two CHP generators with 3 MW capacity, and the simulation is performed in ETAP software.