Performance assessment of stand‐alone transformerless inverters

Summary There is a significant improvement in the efficiency and reliability of photovoltaic inverter by using transformerless topologies. But, the issues related to voltage regulation and total harmonic distortion (THD) needs to be addressed deeply. This paper aims to study the performance parameters like voltage regulation, efficiency, and THD of highly efficient transformerless inverters. In addition to this, a modified topology is proposed, which exhibits improved performance while operating with controllers, such as fuzzy and neuro‐fuzzy, are implemented. Simulation is performed using MATLAB. A prototype of the proposed transformerless inverter is also developed in the lab along with the modified control. The proposed topology isolates the photovoltaic (PV) array form the load during the zero‐voltage state. When operated in stand‐alone mode with an intelligent controller, the proposed topology provides benefits with low THD, less power loss, improved voltage regulation, enhanced performance, and efficiency. The result shows an error of 1% in the nominal value of output voltage under varying load and ambient conditions. Settling time is observed to be less than 0.1 seconds for both simulation and prototype. THD is observed at 1.9% for simulation and 2.1% for prototype results, which is better than the previous work.