A Computer-Aided Design System for Protecting Substations and Overhead Power Lines from Lightning

A computer-aided design system (CAD) for the protection from lightning of the unit substations and overhead power lines was developed. A software package containing a calculation model of areas protected from direct lightning strikes, backflashover of the primary and secondary insulation, induced pulse voltage in the secondary circuits, protection from lightning of the power lines, and protection of power substations against the lightning overvoltage along with the overhead power lines was developed. A database of the generic solutions for protection from lightning was developed, it being a structured collection of files containing the layout of buildings and equipment at the substation and the arresters’ layout plan with taking into account the electromagnetic compatibility. A database for earthing arrangement of arresters is the structured set of the typical arresters earthing. In order to find the required generic solution, the user selects the desired file by parameters using the standard tools for working with Windows files. On the basis of the regulatory documents on system and software engineering, the procedure for verification of the computer programs, to be applied as a part of the CAD for the protection from lightning of substations and overhead power lines, was developed. The verification procedure is based on testing of computer programs, as part of the developed system, using test sets containing the test cases. Test cases and test sets for testing the computer programs were developed. The computer-aided design system (CAD) allows significantly reducing the cost for designing of the protection from lightning and improving the quality of the projects.