A cost‐effective single‐phase semi flipped gamma type magnetically coupled impedance source inverters

• Published in: International journal of circuit theory and applications 2021-04, Vol.49 (4), p.1078-1102
• Main Authors: T.N., Gautham, Reddivari, Reddiprasad, Jena, Debashisha
• Format: Article
• Language: English
• Subjects: Coils (windings); Configurations; Converters; differential boost; doubly grounded feature; Embedded structures; Impedance; Inrush current; Inverters; Leakage current; magnetically coupled impedance source inverter; semi flipped gamma MCIS inverter; semi‐Z‐source inverter; System reliability; Topology; Voltage gain
• ISSN: 0098-9886; 1097-007X
• DOI: 10.1002/cta.2865

Summary This paper presents a new two winding coupled inductor architecture for a semi magnetically coupled impedance source (SMCIS) inverter by connecting the coupled inductor windings in flipped gamma fashion. The proposed topology is derived from the conventional MCIS inverters. It can produce sinusoidal output voltage/current without using any shoot‐through operation and output LC filter, which improves the system reliability. Further, a doubly grounded feature, no start‐up inrush current, reduced component count, low input current ripple, continuous output currents, and small leakage currents are the major advantages of the proposed inverter. However, the proposed semi flipped gamma MCIS inverters still suffer from limited output voltage gain problem. The voltage‐boosting feature is added to the proposed inverter by connecting two converter modules in differential boost configuration through the embedded structure. The voltage‐boosting ability is the major advantage of this differential boost embedded configuration. It has flexibility in choosing a wide range of duty cycle operation from zero to one (whereas, the duty cycle was limited to 0.666 in case of semi‐Z‐source inverter [ZSI]). The modes of operation, design procedure, and feature comparisons of proposed inverters are discussed in this paper. Finally, the effectiveness of proposed inverters is validated through simulation and experimental results in terms of component count, voltage gain, and feature comparison. In this paper, a cost‐effective semi flipped gamma MCIS inverter and its embedded MCIS inverter are presented by utilizing magnetically coupled inductors. However, the proposed semi flipped gamma MCIS inverter is unable to produce symmetrical voltage gain across the load. The symmetrical voltage gain is obtained by connecting two flipped gamma converters in an embedded fashion. The low‐cost polypropylene bipolar capacitors are used in a laboratory prototype rather than electrolytic capacitors to avoid dc offset in the capacitor voltage waveforms.