DESIGN AND ANALYSIS OF QUASI CASCADED MULTI-LEVEL INVERTER

This paper presents new topology of Quasi multi-level inverter (MLI) with five level output voltage. Traditional cascaded MLI is a buck DC-AC conversion circuit, which puts a limit on the peak AC voltage. However, within the proposed converter a shoot through state is implemented to increase the output voltage. The number of passive components used in the circuit is less, thereby reducing size, cost and weight. The voltage unbalance problem is prevented by using a low voltage capacitor between the two full bridge outputs. The capacitor voltage of each module is organized with a PI controller to generate the switching pulses for switches of the proposed structure. Simulation results are added to examine the feasibility.