Sahaya A Ponrekha1,2, M.S.P. Subathra1, and C. Bharatiraja This email address is being protected from spambots. You need JavaScript enabled to view it.2

1Department of Electrical and Electronics Engineering, Karunya Institute of Technology and Sciences, Coimbatore, Tamilnadu, India, 641114
2Department of Electrical and Electronics Engineering, SRM Institute of Science and Technology, Kattankulathur, Tamilnadu, India, 603203


 

Received: July 27, 2021
Accepted: December 16, 2021
Publication Date: January 28, 2022

 Copyright The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.


Download Citation: ||https://doi.org/10.6180/jase.202212_25(6).0006  


ABSTRACT


Transformerless inverters are prominently used in the single-phase grid-connected system due to their reduced size, weight, and high efficiency. Common-mode leakage current is the main issue of transformerless inverters, which has to be mitigated. An AC-decoupled high gain inverter is proposed in the inverter capable of attaining the gain more than ten times. Hence, even if the PV voltage is less, the inverter can continue to supply the grid. Unlike the two-stage inverters, the proposed inverter doesn’t require the DC-link capacitor, and it’s charging diode between the boosting and inverter stages. The AC-decoupling method used in the inverter helps to reduce the leakage current within the German standard limit VDE0126-1-1. A detailed steady-state analysis of the inverter is presented. The proposed inverter is simulated in the MATLAB Simulink platform to validate its working principle. The comparative loss and thermal analysis of the semiconductor switches made of three different materials (Gallium Nitride, Silicon Carbide, and Silicon) are made in the PLECS platform. The comparative analysis proves that the proposed inverter with Gallium Nitride made switches offers higher efficiency and reliability.


Keywords: Transformerless inverter, Common-mode voltage, Common-mode leakage current, Loss analysis


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