Design and comparison of medium voltage multi-level converters for industry applications

This paper describes the design of a (2.3 kV, 2.4 MVA) two-level -, three-level - neutral point clamped -, three-level - flying capacitor - and four-level - flying capacitor - voltage source converter on the basis of state-of-the-art 6.5 kV, 3.3 kV and 2.5 kV IGBTs. The semiconductor loss distribution, design, and costs of semiconductors and passive components are compared for a constant converter efficiency of 99 %. Assuming a constant installed switch power the converters are also compared at the maximum switching frequency of each converter resulting in the minimum expense of passive components.