13PE8
Generalized Multi cell Switched-Inductor
and Switched-Capacitor Z-Source Inverters
Ding Li Poh Chiang Loh ; Miao Zhu ; Feng Gao ; Blaabjerg, F.
Power Electronics, IEEE Transactions on (Volume:28 , Issue: 2 ) DOI:10.1109/TPEL.2012.2204776
Publication Year: 2013, Page(s):837 - 848
Project Title : Generalized Multi cell switched-inductor and switched-capacitor Z-
Z-source inverter
Domain :Power Electronics
Reference :IEEE
Publish Year :2013Page(s): 837 - 848
D.O.I :10.1109/TPEL.2012.2204776
Software Used:MATLAB
Developed By:Wine Yard Technologies, Hyderabad
Generalized Multi cell Switched-Inductor
and Switched-Capacitor Z-Source Inverters
Traditional voltage-source inverter is limited by its only voltage step-down operation, while current-source inverter is limited by its only current step-down mode. In order to add an extra boosting flexibility while keeping the number of active semiconductors unchanged, voltage-type and current-type Z-source inverters were earlier proposed. These new classes of inverters are generally more robust and less sensitive to electromagnetic noises. However, their boosting capabilities are somehow compromised by high component stresses and poorer spectral performances caused by low modulation ratios. Their boosting gains are, therefore, limited in practice. To overcome these shortcomings, the generalized switched-inductor and switched-capacitor Z-source inverters are proposed, whose extra boosting abilities and other advantages have already been verified in simulation and experiment.
Modern power electronic applications, especially those directly connected to the grid, usually require some voltage boosting. Traditional voltage-source inverters (VSIs) are therefore not satisfactory since they can only step down voltages. To add boost functionality, dc-dc boost converters can be placed before the VSIs. Alternatively, single-stage buck-boost inverters can be used like the Cuk, SEPIC and other similar dc-ac inverters. However, these inverters do not have been intensive follow-up researched. On the contrary, research in another buck-boost inverter, named as Z-source inverter has been proposed.
Despite the aforementioned merits, the aforementioned Z-source inverter topologies also show the following drawbacks: 1) capacitor voltage stress is increased with the increase of shoot-through duty ratio, thus high-voltage or large capacity capacitors should be used, which may result in large volume, high cost, and reducing the life span of system; 2) inductor current stress is large, and this characteristic may also lead to large volume and high cost; 3) it regulates boost factor only by adjusting the shoot-through duty ratio, and boost factor is very small with short shoot-through zero state.
To solve the aforesaid drawbacks in aforementioned Z-source inverter, a new Z-source inverter topology is presented with extended SL network and unique Γ-shaped impedance network without transformer. The operation principle and comparison with the classical ZSI and SL-ZSI reveal the merits of the proposed topology, which are also verified in both simulation and experiment.
Circuit Configurations
Topologies of (a) voltage and (b) current-type Z-source inverters
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Topologies of (a) voltage-type SL and (b) current-type SC Z-source inverters.
Conclusion:
To understand the elementary SL topology, the generalized SL and SC Z-source inverters are derived. Their operating principles are explained with their gains proven to be much higher
than those of the traditional Z-source inverters. Their modulation ratios can be set higher to better utilize their dc links, and to keep their component stresses lower. Simulations have confirmed these advantages, and experiments have verified the inverter practicalities.
Screen shots:
SCREEN SHOTS
Diode current and diode voltage
Dc link voltage.
Experimental dc-link voltage vi , unfiltered ac line voltage vab, and
ac current ioa for N = 2, dST = 0.15, and M = 0.8 × 1.15
Experimental input current Idc , filtered ac voltage vab , unfiltered ac
current ioa , and filtered ac current i’oa for N = 2, dST = 0.15,
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