A Field Programmable Time Overcurrent Relay

This paper presents the underlying principles and the test results for a microprocessor based time overcurrent relay. The main feature is the use of a portable pocket computer with an RS-232C communication link for the man machine interface. The calculator serves to enter and modify the set vatues pick up current, instantaneous characteristics. etc. but also to discretise and transmitt the time current curve and store it on an EEPROM type memory according to individual users´ needs.