Development and Evaluation of a Simple Shunt Module for High DC Current Measurement

This study aimed to develop and evaluate a shunt module for high direct currents (SMHC) to promote efficient use of DC power. Using offset and gain adjustments, the current-measurement error range improved from ±1.0% to ±0.04%, when measuring a 1000 A current. A real-time temperature correction (TC) function was used to improve the current measurement error from a maximum of 0.35% to less than ±0.04%, before and after the application of TC, respectively, for this current. The linearity evaluation showed the relative deviation to be less than ±0.06% for measured current in the range of 50 A to 1000 A. The measurement uncertainty of the SMHC was evaluated based on the guidelines to realize reliable current measurements. The relative uncertainty with confidence interval 95% (expanded relative uncertainty) for the measurement of 1000 A using the SMHC was estimated to be 0.20%.