1. 1 Teaching Innovation - Entrepreneurial - Global The Centre for Technology enabled Teaching & Learning, N Y S S, India DTEL DTEL (Department for Technology Enhanced Learning)

2. DEPARTMENT OF ELECTRICAL ENGINEERING IV - SEMESTER POWER DEVICES & MACHINES 2 UNIT NO. - 4 POWER CONVERTERS (CHOPPERS & INVERTERS)

3. CHAPTER 4 :- SYLLABUSDTEL 1 2 Control Strategies of chopper 3 Inverter & its classification, Working Principle of single phase Half Bridge & Full Bridge Inverter R & RL Load 4 3 Three phase Full Bridge Inverter: 180 degree mode & 120 degree mode 5 Introduction to Chopper & its Working principle Types of Chopper: Step up &Step down chopper, Class A to E chopper

4. CHAPTER 4:- SPECIFIC OBJECTIVE / COURSE OUTCOMEDTEL. Understand the working, types & applications of DC-DC converters. 1 4 The student will be able to:. 2 Understand the working, types & applications of DC-AC converters.

5. LECTURE 1:- DC-DC Converters (Choppers)DTEL 5 5 Introduction Chopper is a static device. A variable dc voltage is obtained from a constant dc voltage source. Also known as dc-to-dc converter. Widely used for motor control. Also used in regenerative braking. Thyristor converter offers greater efficiency, faster response, lower maintenance, smaller size and smooth control.

6. LECTURE 1:- DC-DC Converters (Choppers)DTEL 6 6 According to i/p & o/p voltage levels  Step-down choppers.  Step-up choppers. According to directions of o/p voltage & current Class A chopper Class B chopper Class C chopper Class D chopper Class E chopper According to circuit operation One Quadrant chopper Two Quadrant chopper Four Quadrant chopper According to Commutation Method Voltage commutated choppers Current commutated choppers Load commutated choppers Impulse commutated choppers Classification of Choppers

7. LECTURE 1:- DC-DC Converters (Choppers)DTEL 7 7 Principle of Step-down Chopper

8. LECTURE 1:- DC-DC Converters (Choppers)DTEL 8 8 Principle Of Step-up Chopper

9. LECTURE 1:- DC-DC Converters (Choppers)DTEL 9 9 THANK YOU

10. LECTURE 2:- TYPES OF CHOPPERSDTEL 10 Class A Chopper

11. DTEL 11 LECTURE 2:- TYPES OF CHOPPERS

12. DTEL 12 Class B Chopper LECTURE 2:- TYPES OF CHOPPERS

13. DTEL 13 LECTURE 2:- TYPES OF CHOPPERS

14. DTEL 14 Class C Chopper LECTURE 2:- TYPES OF CHOPPERS

15. DTEL 15 LECTURE 2:- TYPES OF CHOPPERS

16. DTEL 16 LECTURE 2:- TYPES OF CHOPPERS THANK YOU

17. DTEL 17 Class D Chopper LECTURE 3:- TYPES OF CHOPPERS (CONTINUED)

18. DTEL 18 LECTURE 3:- TYPES OF CHOPPERS (CONTINUED)

19. DTEL 19 Class E Chopper LECTURE 3:- TYPES OF CHOPPERS (CONTINUED)

20. DTEL 20 Four Quadrant Operation LECTURE 3:- TYPES OF CHOPPERS (CONTINUED)

21. DTEL 21 LECTURE 3:- TYPES OF CHOPPERS (CONTINUED) THANK YOU

22. LECTURE 4:- CONTROL TECHNIQUES OF CHOPPERSDTEL 22 The output dc voltage can be varied by the following methods. –Pulse width modulation control or constant frequency operation. –Variable frequency control.

23. DTEL 23 Pulse Width Modulation t ON is varied keeping chopping frequency ‘f’ & chopping period ‘T’ constant. Output voltage is varied by varying the ON time t ON LECTURE 4:- CONTROL TECHNIQUES OF CHOPPERS

24. DTEL 24 Variable Frequency Control In this type of control technique, the chopping frequency ‘f’ is varied and either on-time t ON or off-time t OFF is kept constant. Hence this control technique is also known as frequency modulation control. The fig. below represents frequency modulation control for different duty cycles. LECTURE 4:- CONTROL TECHNIQUES OF CHOPPERS

25. DTEL 25 LECTURE 4:- CONTROL TECHNIQUES OF CHOPPERS THANK YOU

26. DTEL 26 Classification of Inverters According nature of input source  Voltage source Inverters (VSI)  Current source Inverters (CSI) According to wave shape of output voltage waveform Square -wave inverter Quasi- Square wave inverter Pulse-width modulated inverter According to method of commutation Line commutated inverters Forced commutated inverters According to connections Series inverter Parallel inverter Bridge inverter LECTURE 5:- DC-AC CONVERTERS ( INVERTERS)

27. DTEL 27 Single phase half-bridge Inverter Fig. Circuit Diagram LECTURE 5:- DC-AC CONVERTERS ( INVERTERS)

28. DTEL 28 Single phase half-bridge Inverter LECTURE 5:- DC-AC CONVERTERS ( INVERTERS) Fig. Voltage & current waveforms

29. DTEL 29 Single phase full-bridge Inverter Fig. Circuit Diagram LECTURE 5:- DC-AC CONVERTERS ( INVERTERS)

30. DTEL 30 Fig. Voltage & current waveforms LECTURE 5:- DC-AC CONVERTERS ( INVERTERS)

31. DTEL 31 LECTURE 5:- DC-AC CONVERTERS ( INVERTERS) THANK YOU

32. DTEL 32 Fig. Power Circuit Three-phase full –bridge inverter LECTURE 6:- THREE PHASE INVERTERS

33. DTEL 33 Sr.No.IntervalDevice ConductingIncoming device Outgoing device 1I5,6,114 2II6,1,225 3III1,2,336 4IV2,3,441 5V3,4,552 6VI4,5,663 Operation table for 180 0 conduction mode LECTURE 6:- THREE PHASE INVERTERS

34. DTEL 34 Fig. Voltage waveforms for 180 0 conduction mode LECTURE 6:- THREE PHASE INVERTERS

35. DTEL 35 Sr.No.IntervalDevice ConductingIncoming device Outgoing device 1I6,115 2II1,226 3III2,331 4IV3,442 5V4,553 6VI5,664 Operation table for 120 0 conduction mode LECTURE 6:- THREE PHASE INVERTERS

36. DTEL 36 Fig. Voltage waveforms for 120 0 conduction mode LECTURE 6:- THREE PHASE INVERTERS

37. DTEL 37 LECTURE 6:- THREE PHASE INVERTERS THANK YOU