ScholarWorks@경상국립대학교

초록

In this study, we present a current-based regression approach for estimating power quality indices, specifically the power factor (PF) and total harmonic distortion (THD), in an industrial roll-to-roll silicone release film-coating machine. The target equipment consisted of inverter-driven servomotors and nonlinear loads, where continuous power quality monitoring was typically constrained by the high cost of power analyzers. We collected 24 h of operational data under actual production conditions, including idle, preparation, and steady-state operations. We experimentally identified clear correlations among the current, PF, and THD, then developed multiple linear regression models using only current status-related variables. Validation experiments conducted at reduced web speeds revealed that, although the average current level increased by approximately 15 A due to differences in the tension-related torque demand, PF and THD exhibited consistent characteristics. We introduced a current-compensation scheme to normalize this effect, resulting in prediction accuracies exceeding 95 % and approximately 90 % for PF and THD, respectively. The proposed method allows for cost-effective power quality monitoring using low-cost current sensors in industrial environments.

키워드