This paper has presented a modular single-phase tra
ns-Z-source inverter and one of its applications for multi-input
renewable energy system. Evolved from the originalthree-phase Z-source inverter, the proposed single-phase trans-Z-source inverter utilizes coupled inductors and center-tapped capacitors to couple the inverter bridge and DC source. By introducing the shoot-through states, the proposed circuit can boost the input DC voltage to a desired level and
simultaneously output sinusoidal voltage or current
. The
permissible shoot-through operation indicates an in
trinsic
immunity to EMI noises. Moreover, the single-stage
structure
achieves the DC-DC conversion and DC-AC inversion b
y
using only two active switches such that the reduce
d cost and
enhanced reliability are achieved.
The proposed modular single-phase trans-Z-source in
verter
can be applied to multi-input renewable energy syst
em by
flexibly interconnecting different inverter modules
. Unlike the
conventional multi-input renewable energy system wh
ich
requires a dedicated DC-DC conversion stage for eac
h source,
the modular single-phase trans-Z-source inverter ba
sed
application eliminates all the extra DC-DC converte
rs.
Furthermore, a shared DC bus among modules decouple
s the
inverter AC outputs from the DC inputs. Hence, inde
pendent
power control is achievable for each source, and ba
lanced
power can be supplied to each phase of the grid.
A design example of a split single phase power gene
ration
system incorporating both a PV panel and fuel cell
is provided
and examined. Simulation results are obtained, show
ing a good
agreement with the theoretical analysis.