The Analysis of Odd Triple Harmonics to Detect Broken Rotor Bar in Delta-Connected Induction Motors

This paper aims to use and explore odd triple harmonics to perform fault detection in delta-connected induction motors, demonstrating their suitability to detect broken rotor bars. Harmonic components arise around the main odd triple components, generated by the interaction of the fault and other effects, such as saturation and voltage unbalance. The paper presents the mathematical modeling introducing the harmonic components, along with experimental results under several load levels, voltage unbalanced, and under inverter-fed power supply, demonstrating the effectiveness of the detection of the odd triple harmonics. The results compare line and phase currents, demonstrating that the proposed harmonics perform satisfactorily in phase current, suitable for fault detection in a wide operating range, including low-load cases.