QUESTION ONE

$($a$)$ power electronics is a subject that concerns the applications of electronic$-$principles into situations that are rated at power level rather than signal level. Based on the $($i$)$ turn$-$on and turm$-$off characteristics $($ii$)$ gate signal requirements, the power semiconductor devices have been classified into three categories state the three categories and briefly explain them

$[6]$

$($b$)$ A power electronic system consists of one or more power electronic converter; a power electronic converter is made up of some power semiconductor devices controlled by integrated circuits. Power electronies converters can be classified into six types as under:

$($i$)$ Diode rectifiers

$($ii$)$ Ac to de converters $($phase$-$controlled rectifiers$)$

$($iii$)$ De to de converters $($De choppers$)$

$($iv$)$ De to ac converters $($inverters$)$

$($v$)$ Ac to ac converters $($cycloconverters or Ac voltage controllers$)$

$($vi$)$ Static switches

Explain briefly each of the above power systems electronics converters.

$[12]$

$($c$)$ explain any two industrial applications of power electronics systems $[2]$

$[$Total marks: $20$

marks$]$