1. POWER ELECTRONICS Instructor: Eng.Moayed N. EL Mobaied The Islamic University of Gaza Faculty of Engineering Electrical Engineering Department بسم الله الرحمن الرحيم EELE 5450 — Fall 2009-2010 Lecture 30

2. Dc Chopper Dc Choppers are of Two Types 1- Buck converter (Step-down converter) 2- Boost converter (Step-up converter)  I n step down chopper output voltage is less than input voltage.  In step up chopper output voltage is more than input voltage.

3. Dc Chopper Problem Input to the step up chopper is 200 V. The output required is 600 V. If the conducting time of thyristor is 200  sec. Compute –Chopping frequency, –If the pulse width is halved for constant frequency of operation, find the new output voltage.

4. Dc Chopper

7. Control system & power electronics

8. 3 Control system The design of intelligent control systems has become an area of modern research. PID Controller Fuzzy Controller System ModelSystemExperience Fuzzy-PID controller Conventional Controller

9. 34 5- Speed Controllers Design Block diagram for the system

10. 35 Three phase induction motor inverter 5- Speed Controllers Design

11. 36 Three phase induction motor inverter 5- Speed Controllers Design

12. 37 Three phase induction motor inverter Mosfet IGBT Thyristor 5- Speed Controllers Design

13. 38 Three phase induction motor inverter 5- Speed Controllers Design

14. 39 Schematic diagram for one line of the inverter 5- Speed Controllers Design

15. 40 Software implementation of the inverter 5- Speed Controllers Design

16. 41 Deadband between upper and lower signals 5- Speed Controllers Design

17. 42 Sine Wave Generation 5- Speed Controllers Design

18. 44 Sine Wave Generation 5- Speed Controllers Design

19. 45 Sine Table skipping method for frequency variable 5- Speed Controllers Design

20. 46 Overall inverter 5- Speed Controllers Design

21. 47 Controllers design 5- Speed Controllers Design

22. 48 Three phase induction motor Two poles. 250W. Rotates at up to 2980 rev/min at 50 Hz. 5- Speed Controllers Design

23. 49 Induction motor model 1- DC resistance Test. 2- Locked-rotor Test 3- No-load test Professor Mahmoud Riaz model 5- Speed Controllers Design

24. 50 Speed Sensor 5- Speed Controllers Design

25. 51 PID Controller 5- Speed Controllers Design

26. 52 Ziegler-Nicholas tuning method 5- Speed Controllers Design TS is equal at least 4 to 20 times the rise time of the system response.

27. 53 PID “sequential” algorithm 5- Speed Controllers Design

28. 54 5- Speed Controllers Design Step response for PID with speed and load variation

29. Motor Drive System End of Lecture