Transformer overload with user-defined characteristic

The authors describe the design and implementation of a transformer overload relay with a user-defined characteristic using a user-accessible software protection system platform which has been developed at the University of Manitoba. The relay design platform is a powerful tool for the user to design his or her own relays. With the background program provided, where many relay function routines have been written and stored in the function library, the user can easily create relay functions using the C high-level language to call the special routines. A relay of any type can be programmed. Some graphics utilities have been developed to help the user design the relay even more easily. The details of the relay prototype design are given and the platform is briefly introduced.