Laboratory Simulation of Numerical Over-Current Protection

Abstract

The development of a hardware simulation of the power system faults and protection by a numerical over-current and earth fault relay in a laboratory environment is depicted in this paper. The development is aimed at providing motivation and creating interest in the students for the complex design of relay setting coordination, fault analysis, control circuit design, communication and configuration of the latest numerical relays. The hardware simulation panel setup comprises of a three-phase two-section radial distribution system. Flexible connections are provided to changeover the numerical relay current input source from the current transformer secondary to the relay test set output. It helps in the multiple uses of the panel for testing, configuring and application of the numerical relay. Two different models of numerical relays, namely SPAJ-140C and REF615 of ABB make are mounted on the panel. The installation, commissioning, testing and configuration for various IEC and IEEE characteristics are accomplished. The work progress is achieved through the final year student projects, thus providing technical and hands-on skills to the students. The laboratory manual has been developed for conducting experiments as a part of the laboratory curriculum for the power system protection course at UG and PG level. The manual and the panel developed are also useful in conducting the training programs for the state power utility company’s engineers as a part of industry–institute interaction.