Adaptive DC Voltage Control for Optimal Junction Temperature Redistribution Under Stall Condition of Electric Machine Drive Inverter

Active thermal controls (ATCs) are becoming an efficient solution to enhance the reliability of power electronics components and systems. In the applications of electric machine drive, ATCs under abnormal conditions, such as overstress in a relatively short timescale, still need further investigations. As one of the control freedoms, the dc voltage has a strong impact to the loss and thermal behaviors of power semiconductor devices. In this letter, the loss and thermal characteristics under the stall condition of the electric machine drive converter are investigated, and an ATC method with Adaptive dc voltage control (ADVC) is proposed. By using the proposed ADVC, the conduction loss and switching loss of the power devices are redistributed intentionally, so that the total power loss and junction temperature under the stall condition can be minimized. Furthermore, a speed-based-coefficient digital filtering algorithm is applied for dc voltage reference calculation, so that the ADVC performs self-adaptive to the rotor speed and be integrated into the original control structure of the drive converter. Simulations and experimental results are provided to validate the effectiveness of the proposed method.