Abstract
This paper describes that Si power devices has remarkably made progress of power electronics since 1960s, but the operational junction temperature of Si power devices do not generally make progress for 40 years, and the improvement of switching frequency of Si power devices do not expect in feature. And this paper shows the effect of replacement of Si power device with SiC power devices. Furthermore this paper shows that in 21st century electric energy storage system with long life and high cost-performances is required. One of the desirable electrical energy storage devices is EDLC (Electric Double Layer Capacitor). This paper shows recent technical information of the EDLC.
