Cascaded H-Bridge inverter has been researched for the past two decades, but there are no explicit guidelines on how one can realize a cascaded NPC （neutral-point-clamped）/H-Bridge inverter. Past research has also c...Cascaded H-Bridge inverter has been researched for the past two decades, but there are no explicit guidelines on how one can realize a cascaded NPC （neutral-point-clamped）/H-Bridge inverter. Past research has also concentrated on realizing a five-level NPC/H-Bridge inverter. This fails to address the principle of realizing a general cascaded N-level NPC/H-Bridge PWM inverter. This paper proposes an improved topology for achieving a nine-level cascaded NPC （neutral-point-clamped） H-Bridge inverter with reduced harmonic content. This new proposed topology requires a lesser number of separate dc sources as compared to conventional cascaded H-Bridge inverter. The whole system is considered as having four three level legs having two positive and two negative legs. By properly phase shifting the modulating wave and carriers, a nine-level output is achieved. A theoretical harmonic analysis of the proposed inverter is carried out based on double Fourier principle. The theoretical results are verified through MATLAB simulation.展开更多
文摘Cascaded H-Bridge inverter has been researched for the past two decades, but there are no explicit guidelines on how one can realize a cascaded NPC （neutral-point-clamped）/H-Bridge inverter. Past research has also concentrated on realizing a five-level NPC/H-Bridge inverter. This fails to address the principle of realizing a general cascaded N-level NPC/H-Bridge PWM inverter. This paper proposes an improved topology for achieving a nine-level cascaded NPC （neutral-point-clamped） H-Bridge inverter with reduced harmonic content. This new proposed topology requires a lesser number of separate dc sources as compared to conventional cascaded H-Bridge inverter. The whole system is considered as having four three level legs having two positive and two negative legs. By properly phase shifting the modulating wave and carriers, a nine-level output is achieved. A theoretical harmonic analysis of the proposed inverter is carried out based on double Fourier principle. The theoretical results are verified through MATLAB simulation.
