Contribution to experimental investigation of fitting the current transformers' calibration curves

Abstract

The paper experimentally investigates the problem of fitting calibration curves of current transformers (CTs). An efficient fitting algorithm enables precise and accurate electronic real-time correction of CT errors and thus effective improvement of their accuracy class. The paper presents the results of a novel algorithm that allows correcting the transformers' current ratio error from 0.25% to within 0.004%, based on 8 key calibration points in the range 1% to 200% of the CT's nominal primary current, in line with the new IEEE Standard.

Keywords

• curve fitting
• calibration curve
• accuracy class
• current transformer