Impact of reduced common mode voltage-PWM techniques on stator winding temperature using reliable thermal model: theoretical and experimental studies

Purpose This paper aims to deal with theoretical and experimental studies of the impact of the reduced Common Mode Voltage (CMV)-Pulse Width Modulation (PWM) techniques on stator winding temperature using a reliable thermal model. Design/methodology/approach To deal with the CMV, reliable PWM algorithms with the reduced CMV and suitable overall performance are developed in this paper. After developing the mathematical model of the proposed electro-thermal approach, the reduced CMV PWM approaches are then evaluated in terms of stator winding temperature impact. The experimental tests are carried out on a two-level voltage source inverter-fed induction machine using a Virtex 5 LX50T field-programmable gate array board. The studied techniques are compared to the conventional one in terms of CMV, leakage current, current total harmonic distortion and stator winding temperature. Moreover, the reliability of the thermal model is proven by numerical and experimental tests. Findings The simulation and experimental results confirm that the suggested diffusive thermal model shows high reliability in terms of continuous temperature control and perfect concordance with the measured results. Furthermore, when comparing the studied PWM methods in terms of winding temperature, it is concluded that the conventional approach provides the best performance, whereas the active zero state PWM shows a slight temperature reduction in comparison with the near state PWM. On the other hand, it is noted that the important temperature increase is detected on the nondrive side and drive side ends of the stator winding when the stator iron presents the smallest one. Originality/value Two important issues of induction machine failure, namely, the CMV and the stator winding temperature, are studied. To deal with the CMV issue, two PWM algorithms for CMV reduction are applied and then evaluated in terms of stator winding temperature proposing a reliable electro-thermal model. The thermal management can be used to trigger proactive cooling actions or schedule preventive maintenance interventions, thereby reducing the maintenance costs, minimizing the unexpected downtime and enhancing the operational safety.