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 converte
r are suitable for iudustrial drive applications, such as rolling mills, wa
ter pumps, and so on, and they are composed of multi-inverter units in para
llel, Each inverter omit is composed of four pairs of parallel. IGBT's conn
ected in series. In order to share current among the parallel-connected IGB
T's, influences of wiring inductance and device characteristics are evaluat
ed by simulation using novel power device models and experimental results,
To reduce both switching voltage swing and power consumption, a variable-ca
pacitance snubber circuit is also presented for the NPC inverter.