Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Single Phase 5-level Inverter with DC-link Switches
Authors Young-Tae Choi ; Ho-Dong Sun ; Min-Young Park ; Heung-Geun Kim ; Tea-Won Chun ; 魯Eui-Cheol Nho
DOI 10.6113/TKPE/2011.16.3.283
Page pp.283-292
ISSN 1229-2214
Keywords Multi-level inverter; Power conditioning system; Renewable energy sources; PWM strategy; Voltage balancing
Abstract This paper proposed a new multi-level inverter topology based on a H-bridge with two switches and two diodes connected to the DC-link. The output voltage of the proposed topology is quite closer to a sinusoidal waveform compared with a typical single phase inverter. The proposed multi-level inverter is applicable to a power conditioning system for renewable energy sources, and it can be also used as a building block of a cascaded multi-level inverter for a high voltage application. In case of conventional H-bridge type or NPC type multi-level inverter, 8 controllable switches are used to obtain a 5 level output voltage, but the proposed multi-level inverter requires only 6 controllable switches. Thus the circuit configuration is quite simple, reliable and cost-effective implementation is possible. The efficiency can be improved owing to the reduction of the switching loss. A new PWM method based on POD modulation is suggested which requires only one carrier signal. The switching sequence to make the capacitor voltage balanced is also considered. The feasibility is studied through simulation and experiment.