Comparison of power semiconductor utilization, losses and harmonic spectra of state-of-the-art 4.16 kV multi-level voltage source converters

This paper compares a three-level neutral point clamped voltage source converter (3L-NPC VSC), a three-level flying capacitor voltage source converter (3L-FLC VSC), a four-level flying capacitor voltage source converter (4L-FLC VSC) and nine-level-series connected H-bridge voltage source converter (9L-SCHB VSC) on the basis of state-of-the-art 6.5 kV, 4.5 kV and 1.7 kV IGBTs for a 4.16 kV medium voltage converter. The design of the power semiconductors, the installed switch power, converter losses, the semiconductor loss distribution, modulation strategies and the harmonic spectra are compared in detail.