This paper proposes a novel modulation technique for switching losses reduction in modular multilevel converters (MMCs). The MMC
is considered as the development trend
topology for medium- and high-voltage applications. However, the MMC requires
numerous
power devices to generate demanded output
quality. Plenty of power devices generate enormous power losses for the system
with
requiring high cost and a large heat sink
for each of the device. For that reason, this paper proposes the hybrid
modulation method
for the switching losses reduction in the
MMC. The proposed modulation scheme combines fundamental-frequency modulation
(FFM)
scheme and phase-shifted carrier based
pulsewidth modulation (PS-PWM) scheme. In addition, an additional rotation
method is
included for voltage-balancing and power
distribution among the sub-modules (SMs). Finally, the power losses of
three-phase MMC
are decreased with retained good output
quality of the system. Simulation and experimental results are included to show
and verify
the performance of proposed hybrid
modulation method.