Presented by Bibek Karki, IPS Power Serve

Abstract— With electromechanical and solid-state protective relays being obsolete and nearing their end of life, upgrading them with their microprocessor counterparts is paramount for reliability of power system. Microprocessor relays provide advanced communication, monitoring and automation capabilities along with all basic protection and control platform. The advancement in technology in power industry coupled with increase in awareness about arc flash hazards, has brought a wave of arc flash hazard mitigation processes and procedures. If the protective relay upgrade project is planned in advance, the arc flash hazard mitigation could become an amazing complementary result along with the relay upgrade. The key to this process is: adequate planning and selecting appropriate relays to achieve both goals. This paper provides a snapshot between these concurrent topics in current power industry and how the communication and automation capabilities of microprocessor relays could be leveraged in arc flash hazard mitigation. This paper also dives into various methods and procedures for arc flash mitigation such as maintenance mode settings, programming a breaker open/close delay, remote opening and closing the device, installing virtual Main, expanding differential zone of protection etc. supplemented by SKM simulation results and case studies from field projects. Arc Flash hazard mitigation goals can be achieved without compromising power system reliability, harnessing the advancement in protective relaying technology. Keywords— relay upgrade, arc flash, risk mitigation, remote operation, protective relay.