Exploring the effects of overvoltage unbalances on three phase induction motors: Insights from motor current spectral analysis and discrete wavelet transform energy assessment

Abstract

This paper explores the diagnosis of faults related to 10 % and 20 % overvoltages in phase A of a three-phase induction motor. The study is based on numerical simulation results using MATLAB software. The primary objective of this research is to investigate the impact of such voltage unbalance on induction motors, principally on the three-phase stator currents and the electromagnetic torque. The results demonstrated that this voltage aberration causes significant harm to the motor. This is evidenced by the resulting highly unbalanced stator currents and oscillatory torque leading to subsequent mechanical disturbances.The study's second objective is to diagnose anomalies using Motor Current Spectral Analysis (MCSA), encompassing a comprehensive analysis of all three phases. The analysis proved to be effective in detecting such faulty circumstances. The direct current (Id) and the quadrature current (Iq) were also analyzed to reinforce the study. Providing an alternative perspective to explore the consequences of the imbalance. To enhance these findings and validate the previous analysis, the energy analysis based on Discrete Wavelet Transform (DWT) was applied to the three phases, Id and Iq currents.The assessment focused on energy analysis, enabled the detection of abnormal conditions, and demonstrated a noteworthy coherence with spectral analysis. The observed congruence provides evidence for the dependability and effectiveness of these methods in identifying faults, whether they are used in combination or separately.