Power measurement in energy efficient manufacturing: Accuracy analysis, Challenges, and Perspectives for improvement

Abstract

To acquire the electrical energy consumption of manufacturing system, power monitoring and recording are widely adopted in various machines. The accuracy of power measurement is of significance to perform efficient manufacturing. However, the dynamic and high-order harmonics caused by inverter components and uncertain loads, have great influences on the measured results. In this paper, the power accuracy affected by different sampling rates was first analyzed using Fourier transform theory to reveal the possible errors occurring in measurement. Then, a case based on a commonly used two-level PWM (Plus Width Modulation) VVD (variable velocity drive) controlling motor system in manufacturing system was performed. Finally, considering various costs in the manufacturing system, challenges for accurately measuring the power were understood and summarized based on the load characteristics. Furthermore, perspectives were discussed to achieve more accurate power monitoring for the manufacturing system. This work contributes to monitoring the power consumption more effective for efficient manufacturing.