PLC/HMI-Based Implementation of a Real-Time Educational Power System Protective Relays Platform

Abstract

Engineering laboratories are key elements in engineering learning and are essential for a concrete understanding of engineering topics and experiments. These key laboratories are no longer just hardware-dependent, they are a creative combination of programmable hardware and also user-defined driving software. In this work, an educational power system protective relaying laboratory platform was designed and implemented using a programmable logic controller (PLC) and human–machine interface (HMI) in order to introduce engineering students to the operating mechanisms experimentally. It engaged the students in selecting settings and upgrading the inverse definite minimum time (IDMT) protection relays for overcurrent, overvoltage, undervoltage, and differential current. With the platform and the help of the HMI, the students mastered (or came close to mastering) the field of protective relays, especially those explicitly implemented in the platform. The students were also able to see the real-time response that is equivalent to the relay operation time of the protective relays under the various possible settings, and the kinesthetic learning that was involved gave them a deeper understanding of what is involved in relays upgrading.