Performance Analysis of Cascaded Z-Source Multilevel Inverter using Third Harmonic Injection PWM

Multilevel Inverter (MLI) has been recognized as an attractive topology for high voltage DC-AC conversion. Function of a multilevel inverter is to synthesize a desired voltage wave shape from several levels of DC voltages. But the main drawback of MLI is its output voltage amplitude is limited to DC sources voltage summation. To overcome this limitation, a five-level cascaded multilevel inverter based Z-source inverter has been proposed in this paper. In the proposed topology output voltage amplitude can be boosted with Z network shoot-through (ST) state control. This paper focuses on third harmonic injection pulse width modulation (PWM) strategy for the proposed topology. Performance parameters of Z -Source MLI have been analyzed for third harmonic injection modulation strategy. A simulation model of conventional cascaded multilevel inverter and Z-source MLI has been built in MATLAB/SIMULINK and its performance has been analyzed.