Adaptive Protection Scheme for a Microgrid with High Levels of Renewable Energy Generation

Deployment of high renewable energy based penetration in a distribution network increases the fault current levels and therefore it becomes imperative to review the protective device coordination study. Traditional relaying schemes may fail to protect the distribution system with high penetration of distributed generators (DGs) such as grid-tied photovoltaic, diesel generators and wind energy based systems. This paper investigates the impact on protective device coordination under high DG deployment. IEEE 13 bus test feeder has been modeled in ETAP software to perform the device coordination study with and without (photovoltaic) PV/wind power sources. A novel adaptive protective scheme is proposed using numerical relays compatible with IEC 61850 standard. To implement the algorithm, a laboratory based microgrid test bed has been modeled with logical nodes based on the IEC 61850 communication protocols. The limitation of modern numerical relays to update the settings in real-time has been discussed.