In the particular embodiments described, an unlimited voltage static power
converter includes an array of multi-level phase drivers consisting of a
plurality of H-bridge power modules connected in series. The midpoint node
of the series-connected power semiconductors is connected to corresponding
midpoint nodes in adjacent H-bridges to achieve a desired high output
voltage using available power switch ratings. A three-dimensional
multi-level, multi-phase, multi-circuit array of H-bridges permits the use
of the static power converter for high power applications, while providing
a high degree of power quality. The power semiconductor switches are
operated in accordance with a two-dimensional interleaved pulse width
modulation algorithm which produces a waveform with a switching frequency
that can be more than an order of magnitude higher than the switching
frequency of a single power switch. PWM complementary triangle carrier
waves are used for individual PWM control of each H-bridge in each
multi-level phase driver, resulting in a two-dimensional interleaved
control algorithm. Injection of harmonic or non-harmonic content into the
PWM reference waveform further reduces harmonic and non-harmonic content
of the output voltage waveforms. Part-load efficiency is increased using
unique load partitioning methods, five of which are described herein.