Indian Journal of Science and Technology

Abstract

Problems associated with mal operation of relays or Non operation of relays results in larger outage time and huge commercial loss in process industries and power plants. This paper proposes a new technique for set-ting all Over Current (OC) relays in substations, process industries with cogeneration and distribution system with Embedded Renewable Generation. This technique is more suitable where there is a drastic change in the fault current based on the network topology and configuration. It is based on an appropriate equivalent circuit of the power grid to estimate the required short-circuit currents. This technique is used in setting the OC relays of an IEEE 30 Bus system, Real time steel industry and a Real time distribution system with Embedded Renewable Generation. Plug setting, Time Dial setting and Type of curve are optimized which results in better coordination in terms protection of components and maintaining the time interval between down stream and upstream relays. There is a significant reduction in fault clearing time which reduces the damage and enhance the stability. In addition, it also prevents all the mal operation of relays and nuisance tripping. This concept will helpful in developing the auto setting relays in the future. Process industries with cogeneration and medium voltage transmission system are potential application for proposed methodology.

Keywords: Adaptive Setting, Automatic Setting, Distribution System, Embeded Renewable Generation, Over Current relays, Relay Coordination