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 Lecture 30

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.

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.

Dc Chopper

Control system & power electronics

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

34 5- Speed Controllers Design Block diagram for the system

35 Three phase induction motor inverter 5- Speed Controllers Design

36 Three phase induction motor inverter 5- Speed Controllers Design

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

38 Three phase induction motor inverter 5- Speed Controllers Design

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

40 Software implementation of the inverter 5- Speed Controllers Design

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

42 Sine Wave Generation 5- Speed Controllers Design

44 Sine Wave Generation 5- Speed Controllers Design

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

46 Overall inverter 5- Speed Controllers Design

47 Controllers design 5- Speed Controllers Design

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

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

50 Speed Sensor 5- Speed Controllers Design

51 PID Controller 5- Speed Controllers Design

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.

53 PID “sequential” algorithm 5- Speed Controllers Design

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

Motor Drive System End of Lecture