High power converter technologies for saving and sustaining energy

The power converters have been improved with the development of power devices. The development of high-speed switching power devices enhanced the market of voltage source converters in many industrial fields. On-state loss and switching loss of power devices are significantly decreased. Thus, the size of power converters become small and the power converters with less heat generation have little environmental stress. This presentation discusses several kinds of voltage source converters based on three-level converter topology and introduces the UPS (Uninterruptible Power Source) system as an application of several hundreds kVA converters. Next the power electronics technology trends for renewable energy, especially for MW-rated PCSs (Power Conditioning Systems) for utility-scale PV power generation plants are discussed. Finally, as an application of multi-level converter rated several tens of MW, five-level extra-large capacity power converters are introduced. Nowadays development of power devices are moving from silicon base devices to wide band-gap semiconductors. This directivity will drive development of more efficient, much smaller and environmentally friendly converters.