Investigation of power rectifier under non-sinusoidal input based on hybrid multilevel converter

This paper discusses a power rectifier based on a cascaded topology composed of a three-leg cell and three H-bridge cells. Each leg of the three-leg cell is cascaded connected to an H-bridge cell. Since different types of converter are series-connected, the topology is assumed to be hybrid. The capacitors of the H-bridge cells operate as floating capacitors. It is shown that the discussed topology permits the operation even if the grid voltages present harmonic components without the need to increase the capacitor voltages. Control and Pulse Width Modulation strategies are explained in order to adjust the capacitor voltages and grid currents. Simulation and experimental results demonstrate the validity of the discussed strategies and the feasibility of the system. The hybrid topology has its harmonic distortion and semiconductor losses values compared to the ones obtained with the conventional three-leg converter.