A Novel Single-Stage Buck-Boost Transformerless Inverter with Fuzzy Control for Single Phase Grid-Connected Solar PV Systems

Abstract

This work presents a novel single-stage buck–boost transformerless inverter (BBTI) suitable for single-phase grid-connected photovoltaic (PV) systems. In the proposed structure, the PV source is directly referenced to the grid neutral, thereby eliminating leakage currents and enhancing operational safety. Unlike conventional inverter designs, the topology offers wide operational flexibility through its inherent buck–boost capability, ensuring reliable maximum power point tracking (MPPT) under varying solar input conditions. The inverter operates solely with switched capacitors and requires no inductors, which guarantees symmetrical performance during both positive and negative half cycles while minimizing overall system size and cost. A simple sinusoidal–triangular pulse-width modulation (SPWM) scheme is employed to regulate switching states, and fuzzy logic control is incorporated to improve dynamic response. The proposed configuration has been validated through MATLAB/Simulink simulations, demonstrating reliable operation, improved efficiency, and strong suitability for grid integration of PV sources.