Comparison Criteria for Electric Traction System Using Z-Source/Quasi Z-Source Inverter and Conventional Architectures

This paper deals with objective criteria to compare conventional electric traction systems composed of a dc–dc boost converter, a voltage source inverter, and a permanent magnet synchronous machine with alternative topologies such as $Z$ -source inverter (ZSI) or quasi $Z$ -source inverter (QZSI). Rather focusing only on efficiencies issues, this paper deals with other relevant criteria. The stored energy in the systems is for instance linked with their passive elements weight, size, or cost. The currents rms values and the stepup voltage ratio are also considered. A complete losses evaluation is given and validated by both simulation and experimental results. The results show that the QZSI exhibits real advantages in terms of passive elements size since the stored energy during one operating cycle is lower than that for the conventional topologies.