1. ECE 442 Power Electronics1 Step Up Converter Close the switch to store energy in the inductor L Open the switch to transfer the energy stored in L to the load via diode D 1

2. ECE 442 Power Electronics2 Step-Up Converter Operation Switch closed for time interval t 1, inductor current rises, storing energy When switch opens for time interval t 2, stored energy is transferred to the load, inductor current falls.

3. ECE 442 Power Electronics3 Look at the inductor current When the switch closes, Peak – to – Peak ripple current Inductor Voltage

4. ECE 442 Power Electronics4 When the switch opens - + Average Output Voltage C L connected @ load

5. ECE 442 Power Electronics5 Normalized Output Voltage Cannot be switched ON continuously (k=1)

6. ECE 442 Power Electronics6 Application Transfer of energy from one voltage source to another

7. ECE 442 Power Electronics7 Operational Mode 1 Switch closed (I 1 = Initial Current)

8. ECE 442 Power Electronics8 Operational Mode 2 Switch opened (I 2 = Initial Current) V s < E for Stable System

9. ECE 442 Power Electronics9 Current Waveform

10. ECE 442 Power Electronics10 Step-up Converter with Resistive Load

11. ECE 442 Power Electronics11 Operational Mode 1 When the switch is closed, (0<= t <= kT) Initial Current

12. ECE 442 Power Electronics12 Operational Mode 2 When the switch is opened, (t = kT) Initial Current

13. ECE 442 Power Electronics13 Initial Currents At the end of Mode 1 At the end of Mode 2

14. ECE 442 Power Electronics14 Solving for I 1, I 2, and Ripple Current

15. ECE 442 Power Electronics15 Example 5.4

16. ECE 442 Power Electronics16