IGBTs major application drives from their ability to switch at control demand at reasonable high frequency 1k-2k in power circuits for AC drives and few 100 KHz in UPS type of application. IGBTs are virtually dominated Ac drive field in almost all area of medium voltage application eg Transportation (Locomotives, EMUs Metros), cement, paper industry to common motion application. And has almost replaced DC motor drives due to robust design of motor less maintenance, better control, efficiency and regenerative capability of drive.