EE1F24- Power Electronics

Question 1

What is power electronics?

Answer 1

-The application of power switching devices

Question 2

Why do we use power electronics?

Answer 2

Power electronics is the most efficient way to control electric power whereever there is a need to modify a characteristic (voltage, current, frequency) of some electrical energy

Question 3

What is a switch?

Answer 3

An electrical component which can break an electrical circuit interrupting the current or diverting from one conductor to another.

Question 4

What are some switches used in power systems?

Answer 4

-CB’s
-SW
-Mechanical switching
-Has a moving part
-Low switching frequency

Question 5

What are some features of an ideal power switching device?

Answer 5

-Unlimited current and voltage rating
-Zero turn on and turn off time- unlimited switching frequency
-No power loss on operation (P=VI)
-When ON, no voltage drop across the switch, Vsw=0
When OFF, no current flow through the switch

Question 6

What are features of practical power switching devices?

Answer 6

-Limited current and voltage rating
-Limited switching speed, finite turn on and turn off times, limits maximum operating frequency of device
-ON state resistance and OFF state leakage current
-Power losses, ON/OFF losses, switching losses
-Losses can increase, with switching frequency, with turn on/off times

Question 7

What are the different types of power electronics converters?

Answer 7

-DC to DC (chopper)
-AC to DC (rectifier)
-DC to AC (Inverter)
AC to AC converters (AC voltage regulator)