A.Rajkumar
PG student-
Department of EEE - SBM college of Engineering and technology, Dindigul,
Tamilnadu, India
This
paper presents a cascaded H-bridge multilevel inverter that can be implemented
using only a single dc power source and capacitors. Standard cascaded
multilevel inverters require N dc sources for 2N+1 level. Without requiring
transformers, the scheme proposed here allows the use of a single dc power
source (example: a battery or a fuel cell stack) with the remaining dc sources
being capacitors, which is referred to as Hybrid Cascaded H-bridge Multilevel
Inverter (HCMLI) in this paper. It is shown that the inverter can
simultaneously maintain the dc voltage level of the capacitors and choose a
fundamental frequency switching pattern to produce a nearly sinusoidal output.
HCMLI using only a single dc source for each phase is promising for high power
motor drive applications as it significantly decreases the number of required
dc power supplies, provides high quality output power due to its high number of
output levels, and results in high conversion efficiency and low thermal stress
as it uses a fundamental frequency switching scheme.