Novel 1-$\varphi$ High-Voltage Boosting Transformerless Inverter Topology With Optimal Power Components and Negligible Leakage Currents
Phani Kumar Chamarthi, Utkal Ranjan Muduli, Mohamed Shawky El Moursi, Ahmed Al‐Durra, Vinod Khadkikar, Khalifa Al Hosani, Tarek H. M. EL-Fouly
Abstract
Inverter topologies for integrating a rooftop photovoltaic (PV) unit into a microgrid are becoming increasingly complex. This paper proposes a high-voltage boosting transformerless inverter (HVBTI) topology for enhancing such applications. The coupled inductor-based high voltage gain feature of the HVBTI configuration allows power to be delivered into the grid from a lower voltage PV source without using higher duties. In addition, HVBTI suppresses leakage current as the common connection shared between the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-ve$</tex-math></inline-formula> terminal of the PV source and the grid neutral point. In comparison to existing topologies, the HVBTI topology uses a compact pulse width modulation strategy to control only six controllable switching devices. Again, using lower-rated switching devices is more cost-effective while increasing reliability and efficiency. In a laboratory prototype of a 1 kVA grid integrated system, the proposed HVBTI configuration is validated, and the maximum efficiency of the HVBTI is estimated at approximately 95%.