An Innovative Transformerless Single-Stage Buck Boost Inverter Designed for Single-Phase Grid Connected Solar PV Systems

An inventive single-phase grid-connected solar topology was used in this study. Photovoltaic applications, namely, buck-boost transformer-less inverters, are introduced. This configuration effectively mitigates leakage currents by ensuring that if input photovoltaic sources are comparable to grid's neutral point. Additionally, the proposed design exhibits robust maximum power point tracking (MPPT) capabilities, even under substantial variations in the input PV voltage, facilitated through the buck-boost mechanism. A further advantages of this topology is the incorporation of a singular across the two half-cycles of the grid, thereby enhancing overall system efficiency and performance. Furthermore, three of five switches within proposed architecture operate in any mode with minimal conduction losses, while the remaining two switches function at line frequency, exhibiting negligible switching losses. To regulate proposed inverter topology, a basic pulse width modulation (PWM) using a sine-triangle technique is introduced and rigorously analyzed under all operating conditions. Simulation studies are conducted using MATLAB/SIMULINK to validate the performance and effectiveness of the proposed system.