A Novel Virtual Space Vector Modulation Scheme for Three-Level NPC Power Converter with Neutral-Point Voltage Balancing and Common-Mode Voltage Reduction for Electric Starter/Generator System in More-Electric-Aircraft

In recent years, More-Electric-Aircraft (MEA) becomes the state-of-the-art. One of the essential issue need to be solved is neutral-point (NP) voltage drift in three-level neutral-point-clamped (3L-NPC) power converter because of low power factor (PF) and high modulation index (MI) working condition. Meanwhile, since common-mode voltage (CMV) can damage the motor shaft, thereby degrading the efficiency and reliability of electric starter/generator (ESG) system. In this paper, a proposed modulation scheme is presented based on virtual-space vector concept to achieve both NP voltage balancing and lower CMV. Meanwhile, g-h coordinate is used to overcome excessive computational burden which is common in high-frequency power converter applications. The results of simulation investigation show the effectiveness and significant improvement of proposed modulation strategy in ESG system.