DIGITAL PROTECTIVE RELAYING METHOD FOR TRANSFORMER

摘要

PURPOSE: A digital protective relaying method is provided to accurately judge faults of transformer and magnetizing inrush of transformer by using a fuzzy logic. CONSTITUTION: A digital protective relaying method comprises a step(S10) of detecting and standardizing the primary voltage and current and secondary voltage and current from a transformer; a step(S20) of generating input variables of a fuzzy system including first, second and third input variables; a step(S30) of fuzzifying the input variables generated in the previous step, by a membership function; a step(S40) of performing a fuzzy reasoning by processing the information obtained from the input variables and quantized uncertainty; a step(S50) of defuzzifying the output fuzzy group which is output by a fuzzy reasoning regulation; and a step(S60,S70) of determining whether to trip by judging the normal state, magnetizing inrush state, and faults by using the defuzzified value obtained in the previous step.