This paper describes the design and construction of a neutral-point-clamped (NPC) inverter and converter, with outputs of 0.8, 1.6, and 3.2 MVA, which use insulated gate bipoler transistors (IGBT's), The inverter and converter are suitable for iudustrial drive applications, such as rolling mills, water pumps, and so on, and they are composed of multi-inverter units in parallel, Each inverter omit is composed of four pairs of parallel. IGBT's connected in series. In order to share current among the parallel-connected IGBT's, influences of wiring inductance and device characteristics are evaluated by simulation using novel power device models and experimental results, To reduce both switching voltage swing and power consumption, a variable-capacitance snubber circuit is also presented for the NPC inverter.
