Abstract
This article introduces a comparative study of the losses in Voltage Source Inverter (VSI) based on Metal-Oxide- Semiconductor Field-Effect Transistors (MOSFETs) depending on whether or not the latter are associated with antiparallel diodes. These diodes are optional because MOSFETs have an intrinsic diode capable of conducting reverse currents when their channel is in OFF state. However, it induces additional reverse recovery losses and damaging voltage overshoots. This undesired circumstance occurs during the mandatory switching cell dead-time and is accurately modelled and assessed in this study. Conversely, Schottky diodes feature almost zero reverse recovery losses. Hence, combining each MOSFET with an antiparallel Schottky diode may reduce the converter overall losses. To assess this strategy, an analytical model of the charge stored within the body diode is developed and then compared to experiments using the Double Pulse Test (DPT). It reveals accurate and well suited because it requires only two constant macro parameters which permits to forecast the reverse recovery losses over a wide range of operating conditions, namely switched current, current slope and dead time duration. The selected model is applied in the case where a Schottky diode is placed antiparallel to the MOSFET. It then appears clearly that the interest of such a combination depends on the static characteristics of both the MOSFET and the Schottky diode. This output is a noteworthy point for power electronics designers. Finally, the developed model is applied in the standard use case of the Voltage Source Inverter (VSI). The results reveal the advantage of the suggested model in this use case because the current evolves significantly over time. The outcome of this VSI analysis shows that a significant recovery losses decrease is achieved with good sizing fit between the MOSFET transistor and the additional Schottky diode.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.