A MULTICRITERIA DIFFERENTIAL TRANSFORMER RELAY BASED ON FUZZY-LOGIC

This paper presents a digital relay scheme for the primary protection of power transformers. A multi-criteria algorithm is developed based o n fuzzy sets for the decision making part of the scheme. The cost of w rong decision-making and the amount of information inflow are used alo ng with several standard criteria to improve the reliability of the pr otection. It is shown that the proposed scheme, if properly tuned, can enhance the sensitivity and selectivity of the digital relay and miti gate problems associated with conventional relay schemes.