Experimental Analysis of Thermal Behavior in Induction Motors Experiencing Single-Phase Open-Circuit Faults

Abstract

Induction motors are critical components in hybrid renewable energy systems, including wind-PV-fuel cell microgrids, due to their reliability and operational flexibility. However, their performance is highly sensitive to electrical faults, particularly single-phase open-circuit (SPOC) faults, which can induce significant thermal stress and compromise system stability. This study presents a comprehensive experimental analysis of thermal behavior in induction motors subjected to SPOC faults across varying load conditions and fault durations. High-resolution thermal imaging and embedded temperature sensors were employed to capture spatial and temporal temperature gradients in both stator and rotor components. The findings reveal pronounced asymmetrical heating in faulted phases, with localized temperature rises reaching up to 90°C under sustained full-load conditions, exceeding insulation class limits. Healthy phases exhibited secondary heating due to flux redistribution and circulating currents, demonstrating the complex interplay between electrical asymmetry and thermal dynamics. Comparative analysis with theoretical models confirmed strong correlation between phase current imbalance and localized heat generation, validating the predictive accuracy of existing thermal-electric analogies. The results also highlight the impact of load level and operational regime on hotspot formation, emphasizing the need for load-aware fault mitigation strategies. Implications for hybrid energy systems are significant: SPOC-induced thermal excursions can propagate to coupled power converters and energy storage units, potentially triggering inverter derating, energy inefficiency, or accelerated component degradation. The study provides critical insights for design considerations, recommending real-time thermal monitoring, enhanced insulation, and integration of intelligent fault management algorithms within energy management frameworks. Overall, this research advances the understanding of induction motor thermal behavior under fault conditions, offering empirical evidence to guide resilient motor design and fault-tolerant energy system operation, while establishing a foundation for future predictive thermal modeling in large-scale industrial applications.Keywords: Induction motor, single-phase open-circuit fault, thermal analysis, fault-tolerant design, hybrid energy systems, thermal gradient, insulation degradation, energy management, microgrid, distributed generation., and large-scal.