Title: Novel switching sequence to reduce CMV without increase in current THD for three-level inverter

Authors: R. Linga Swamy

Addresses: Department of Electrical Engineering, University College of Engineering, Osmania University, Hyderabad, India

Abstract: A pulse width modulated three-level inverter fed AC motor generates common mode voltage (CMV) in the motor. Higher CMV leads to premature bearing failures of AC motors. A novel switching sequence is proposed for space vector modulated three-level neutral point clamped (NPC) inverter for partial reduction of CMV. This novel sequence is compared with conventional sequence and will be shown that CMV is reduced and also maintain same current total harmonic distortion (THD) as conventional. The reduction in CMV is achieved by avoiding redundant states. The maintenance of same current THD is verified by obtaining total harmonic distortion using the notion of stator flux ripple. The results are validated with analytical evaluation and experimentation.

Keywords: bearing currents; common mode voltage; neutral point clamped three-level inverter; space vector PWM.

DOI: 10.1504/IJPELEC.2024.136559

International Journal of Power Electronics, 2024 Vol.19 No.2, pp.132 - 151

Received: 27 Sep 2022
Accepted: 23 Feb 2023
Published online: 07 Feb 2024 *

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