Undergraduate Teaching of Electric Network Protection Using Simulations and Lab Experiments
Keywords:overcurrent protection, Power system protection, relay, e-learning
The protection of the electric power system (EPS) elements such as synchronous generators, transformers, transmission lines, and substations is important because it allows having continuity in the electricity service when disturbances are present. Besides, it avoids possible permanent damage to the elements of the EPS. The relays monitor variables as voltages, currents, harmonics, frequency, and active and reactive powers. The function of the relay is to detect an abnormal operating condition, and with the aid of breakers, a faulted equipment can be isolated by just disconnecting only a small portion of the EPS, thus a small number of consumers are affected. The relay setting adjustment is important because it must operate safely, reliable and coordinated. The above can be achieved by teaching students the philosophy, theory, adjustments, and coordination of relays in an electrical network; besides using computer simulation to achieve a more effective teaching. However, to evaluate the performance of a student in programming relay functions, it is needed to carry out the relay adjustment in a laboratory. In this paper, a hybrid approach for teaching electric network protection is presented; it is focused on undergraduate students of electric engineering. It is based on the use of computer simulation of mathematical models and laboratory experiments. To illustrate the proposed teaching approach, lab experiments and simulations of an overcurrent inverse time relay were carried out, where students can review its tripping time in an electrical radial network.