Our final presentation in Power Electronics.

1. Multi-Level inverter
A multilevel inverter is a power electronic device which is
capable of providing desired alternating voltage level at the
output using multiple lower level DC voltages as an input.

2. Group members
• HAMZA SAEED KHAN SP14-EPE-096-6A
• MUJTABA HUSSAIN SP14-EPE-092-6A
• WALI-SHAH AFRIDI SP14-EPE-110-6A
• WASIF ALI SP14-EPE-013-6A
• AMIR SHAHZAD SP14-EPE-003-6A

3. dc to ac inverter block diagram
Power
supplies
DC Power AC Power

4. What is inverter
• Direct current/voltage (DC) converted to alternating
current/voltage (AC).

5. abstracts
• This project generates AC sinusoids up to multilevel.
• It compares existing 2-level inverter with that of our
multilevel inverter.
• ( VSI means Voltage level Inverter )
• We study their effects on voltages
• Existing topologies are same but we get good output from DC
i/p

6. Why this project?

7. Goal…
• To get sinusoidal voltage
• Up to some extent for appliances.
• Because smoothness for every system is very important
• Abrupt change dose not accepted by inductors and capacitors
• So Square wave is not required for us only sinusoidal smooth
wave.

8. What is multi level inverter

9. Multi level inverters
• Preferred to conventional inverters we have
• Capable of producing stepped stair case form as shown next
slide;
• Gives us wave nearer to pure sinusoidal wave we require for
our appliances
• We achieve such a desired output as shown after calculations.
• fast switching of DC signal giving us multiple levels.

10. Why Multi level inverters?
• Because ,In every industry and also in domestic applications,
• Its output is good nearer to sinusoidal voltage as given
example;

11. Structure of our work

12. Output Results

13. Pulse generator for 1st four
positive level trigging.

14. Pulse generator of 5th positive and
first 3 negative level trigging.

15. Pulse generator for 4th and
5th negative level trigging.

16. load current and voltage.

17. Importance of MLI.
• Used in every field.
• It gives us higher power
• Operated through multiple switches
• Power conditioning
• Industrial Motor Drives
• Power Grids
• Transportation

18. Drawbacks
• Having complex structures
• Stresses along the switches.
• Utilizes along the switches
• Utilizes more input sources

19. Demo of inverters

20. Any questions please?

21. Sources
• Source: http://engineering.electrical-
equipment.org/electricaldistribution/introduction-to-
multilevel-inverter.html
• https://www.youtube.com/watch?v=jCNDRb8dda4
• https://www.google.com.pk/search?q=what+is+Voltage+in
verter&biw=1024&bih=648&source=lnms&tbm=isch&sa=X
&ved=0ahUKEwjEzrz7o5XRAhWBbhoKHXFPDCMQ_AUIBig
B#tbm=isch&q=dc+to+ac+inverter+block+diagram
• https://www.google.com.pk/search?q=importance+multile
vel+inverter&biw=1024&bih=599&source=lnms&sa=X&ve
d=0ahUKEwjyj9KKn5bRAhWGPxoKHav_A5MQ_AUIBSgA&d
pr=1#q=importance+of+multilevel+inverter+pdf