Browsing by Author "Gautham, T.N."

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A cost-effective single-phase semi flipped gamma type magnetically coupled impedance source inverters
(John Wiley and Sons Ltd, 2021) Gautham, T.N.; Reddivari, R.; Jena, D.
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. © 2020 John Wiley & Sons, Ltd.
Design Implementation of High Boost Embedded Semi Quasi-ZSI for Photovoltaic System Applications
(Institute of Electrical and Electronics Engineers Inc., 2019) Gautham, T.N.; Reddivari, R.; Jena, D.
The semi Z-source inverter (SZSI) is a well suitable non-isolated converter for grid-connected PV systems, because of its low cost and doubly grounded features. In addition, an SZSI produces a sinusoidal output voltage without using any additional low pass filter circuit. However, the limited output voltage range, the operating region of the duty cycle is restricted to 0.666, discontinuous input currents are the main concerns of SZSI. In order to overcome the above limitations, an embedded semi quasi Z-source inverter (ESqZSI) topology is proposed, that is constructed with two semi quasi ZSIs. Further, a quasi Z-source converter (qZSC) is interfaced as front-end DC-DC converter to implement Perturb and Observe (P and O) MPPT method. The symmetrical and asymmetrical output voltage control methods are presented to improve the voltage profile. The component design specifications and its sizing are clearly discussed for qZSC and ESqZSI. Comparing with H-bridge inverter, the proposed EZSI topology has lower converter ratings, low stress on the system and reduced leakage currents. Finally, the performance of the proposed system is verified through MATLAB/SIMULINK. Â© 2019 IEEE.
Semi-λ Type Single Phase Differential Boost Inverter With High Voltage Gain
(Institute of Electrical and Electronics Engineers Inc., 2023) Gautham, T.N.; Reddivari, R.; Jena, D.
The conventional differential boost inverters have limited voltage gain due to the inductor's parasitic resistance, which limits the output voltage ranges as the duty cycle approaches unity and causes a narrow input voltage range. Moreover, it is also vulnerable to shoot-through problems and a dc-offset problem that leads to high voltage stress across capacitors. The proposed two winding magnetically coupled semi Γ-type structures produce high voltage boosting with decreasing turns ratio (1 < K < 2). The modified PWM scheme is implemented to operate the proposed inverter to overcome the dc-offset problem in output capacitors, which further reduces the voltage stress on the system. Furthermore, provides step-up sinusoidal output voltage/current without LC-filter, dead time, and shoot-through operation. The designed prototype is analyzed for Silicon and silicon carbide (SiC) switch using PSIM thermal module. The features of the proposed inverter are comprehensively compared with state-of-the-art topologies. Finally, the simulation and experimental findings verify the proposed topology. © 2004-2012 IEEE.