Transformer-Based DC-to-AC Grid-Connected Multi-Level Inverter Topology

The traditional line inverters contain line current of square shape in which the harmonics of higher order are present. Due to this, higher order harmonic content EMI is produced due to which large amount of heat in the core of the transformer is triggered. In this paper, a transformer-based grid-connected multi-level inverter topology is presented where transformer with multiple tappings is used to get the output voltage nearly sinusoidal. The output of the inverter is connected to the grid. During each periodic cycle, switching of power electronic devices is done in a very systematic order using the controller circuit. The voltage is given as a command signal to the controller circuit since MOSFET is used as a switch. The complete performance of the DC-to-AC converter is controlled by varying the quantity of the output voltage by utilizing the tap-changing transformer. The analysis of the circuit is done in the MATLAB/Simulink which shows the extreme curtailment in total harmonic distortion.