Microprocessor-Based Protective Relays Applications in Nigeria Power System Protections

Electric Utilities Company of Nigeria (EUCN) have traditionally used electromechanical (EMR) distance relays for the protection of transmission lines in the past, and many such relays are still in use in power systems today. In this paper, microprocessor-based protective relays (MPBRs) applications in the Nigeria power systems protection were investigated. This paper evaluates the performance of a transmission line protection scheme using Microprocessor-based protective and Electromechanical relays using discrete components, for comparison in terms of engineering design, installations, maintenances costs, and applications flexibility. Results shown that maintenance and design of protection schemes using EMR is expensive and time-consuming. MPBRs offer many advantages and benefits over EMR includes compactness, reliability, flexibility, number of installations components, maintenances costs, applications flexibility, are greatly reduced and improved monitoring and control functions. It reduces maintenance costs by providing self-test functions and high reliability, remote targets; metering data memory capabilities, fault location and status information to assist operations in restoration of electrical service. Fault location and event reports provide valuable information leading to improvement in the overall protection schemes. The overall scheme takes up less panel space, the design and wiring is simpler and less costly to implement. Installation and maintenance testing are greatly reduced.