A comparison of Z-Source three-level NPC inverter versus Z-Source two-level inverter

The Z-Source inverter enables a single stage buck-boost conversion which is a useful characteristic in battery supplied electric vehicles. However, the boost operation leads to additional losses in the semiconductors of the inverter. This paper presents a comparison of Z-Source two-level inverter and Z-Source NPC inverters with regard to their total semiconductor losses and loss distribution during boost operation. Furthermore, different topologies of the Z-Source NPC inverter are presented and their ability to short circuit the two Z-Source networks independently is discussed.