Performance Comparison of Five-Phase Three-Level NPC to Five-Phase Two-Level VSI

A multiphase multilevel voltage source inverter (VSI) offers excellent advantages over the traditional three-phase counterparts. Low-order harmonic components with reduced switching losses, lower common-mode voltage (CMV), and the optimum use of dc-link voltage constitute the critical performance indicators for high-efficiency VSI evaluation. Various approaches for carrier-based pulsewidth modulation (CPWM) generation are available in the literature along with space vector pulsewidth modulation (SVPWM) techniques. Comparative analysis shows that the majority of SVPWM strategies have enormous potential than CPWM to achieve the aforementioned performance indices. The main objective of this article is to provide a common platform for the selection of available five-phase VSIs for various industrial applications. For this, a comparative study is carried out to examine in various aspects like CMV, voltage and current total harmonic distortion (THD), switching, conduction losses, and efficiency under the steady-state and dynamic loading conditions over a wide range of the modulation index. It is observed that the five-phase three-level neutral-point-clamped (NPC) VSI has better performance than the five-phase two-level VSI. Experimental results are provided to verify the performance indices of both topologies at steady-state and dynamic conditions.