A new Transformerless Five-level Boost Inverter with Minimum Switch Count For Photovoltaic Application

In photovoltaic systems, the absence of a transformer in inverters offers advantages like cost-effectiveness, smaller form factor, and increased efficiency. This study introduces a five-stage, transformer-less boost inverter designed with a minimized number of switches, employing the switched-capacitor method. The configuration involves six electronic switches, a pair of diodes, and a single floating capacitor. To generate the necessary switching pulses, Sine Pulse Width Modulation (PWM) combined with Level-shifted in-phase disposition carriers is utilized. The paper provides a theoretical elucidation of the five-level operational mechanism. Voltage balancing for the floating capacitor is inherently achieved without requiring additional circuits or logic. To validate the proposed design, simulation tests are carried out, examining output voltage and current profiles along with floating capacitor voltage. These evaluations, conducted using MATLAB/Simulink, further demonstrate the benefits of this inverter design when compared to similar existing models.