VPSfAV: A computational tool to aid the teaching of protection systems

A computational tool for overcurrent protection coordination in electric power distribution systems, with exclusively radial characteristics is developed in this paper. The tool is called Visual Protection System for Assisted Verification (VPSfAV). It is designed to provide students with a simple and visual program capable of verifying protection scheme projects, and to encourage students to develop their own programs. VPSfAV is capable of verifying overcurrent protection schemes in radial distribution systems which is the most common architecture for distribution networks. The computational tool has eight inverse operational time curves, permitting the verification of the protection scheme independent of the chosen relay. The development of VPSfAV focuses on visualization, allowing students to see all the parameters and variables used, as well as graphically plotting multiple overcurrent protection time curves with respect to the observed current in each individual relay. VPSfAV was developed in Visual Basic for Applications, in Microsoft Excel, because students are already used to the platform and majority of university computers already have Microsoft office packages.