Forward Converters Presented by Xinbo Ruan Aero-Power Sci-tech Center Nanjing University of Aeronautics & Astronautics

Transcription

1 Forward Converers Presened by Xinbo Ruan Aero-Power Sci-ech Cener Nanjing Universiy of Aeronauics & Asronauics

2 Oulines 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

3 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

4 How o Selec a Suiable dc/dc Converers - Quesions - Inpu: 60VDC; - Oupu: 48VDC/10A; - Swiching frequency: 100kHz. Please design a dc/dc converer, deermine 1) he volage and curren sress on he power swich, and 2) he volage and curren sress on he he diode. Given he ripple curren of he filer inducance 20%I omax

5 Buck: 60Vin; 48V/10A oupu Q D L f C f R Ld + V o - V o = L f Δi T Lf off 20%I omax = 2 A D=V o / =0.8 v be i Lf I o I Lfmax I Lfmin L f = 48 μh T off =(1 D)T s =2 μs I Lfmax i Q ILfmin i D I Lfmax ILfmin I I I A Qmax = Dmax = Lf max = T 5 T T 0 off on s

6 Buck: 300Vin; 48Vou/10A Q D L f C f R Ld + V o - D=V o / =0.16 T off =(1 D)T s =8.4 μs v be i Lf I Lfmax I o I Lfmax I Lfmin Δ ilf = VoToff Lf = 8.4 A i Q i D I Lfmin I Lfmax I Lfmin I = I = I Qmax Dmax Lf max 8.4 = 10 + = 14.2 A T 6 T T off 0 on s

7 Buck: Comparison of Differen Inpu Volage L f R Ld v be Q D C f + V o - i Lf i Q i D I o Problems: The curren ripple becomes larger; The swiching? devices suffer high volage; Duy cycle is oo small. The inpu is no isolaed wih he oupu. Answer: The inpu volage is no so mached wih he oupu volage.

8 Derivaion of Forward Converer Sep 1: Inroduce a ransformer; Sep 2: Magneic Rese circui; Sep 3: Inroduce a recifier diode. v p φ v p φ

9 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

10 Anoher Form of Forward Converer L f R Ld Rese Circui + v p _ C f

11 Basic Rese Mehod L f R Ld v p + _ C f D

12 Forward Converers wih Rese Winding W 3 L f W 1 W 2 C f R Ld + V o - v p A 1. Duy cycle; 2. Volage sress of. Φ B W W 1 3 W 3 /W 1 i W on r 12 0 T T T s

13 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

14 Dual-Swich Forward Converers D R D FW L f C f R Ld + V o _ Q

15 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

16 Forward Converers wih RCD Snubber L f C f R Ld + V o - L f R Ld C f C s

17 Operaion Principle: [ 0, 1 ] V cc I o vcs A B V Cc i p C s i M I i M (+) I M ( )

18 Operaion Principle: [ 1, 2 ] V cc I o vcs A B V Cc i p C s i M I i M (+) I M ( )

19 Operaion Principle: [ 2, 3 ] V cc I o vcs A B V Cc i p C s i M I i M (+) I M ( )

20 Operaion Principle: [ 3, 4 ] V cc I o vcs A B V Cc i p C s i M I i M (+) I M ( )

21 Operaion Principle: [ 4, 5 ] V cc I o vcs A B V Cc i p C s i M I i M (+) I M ( )

22 Operaion Principle: [ 5, 6 ] V cc I o vcs A B V Cc i p C s i M I i M (+) I M ( )

23 Parameers Design L f R Ld C f vcs A B V Cc 1. V cc V cc _min C s V = V + V VinDy KVo = = 1 D 1 D Q1 in cc 2. R c Magneic Energy y y i p i M I i M (+) I M ( ) Sored by Juncion capacior Dissipaed in he resisance 3. C c ΔV c 5%V cc

24 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

25 Acive Clamp Forward Converer L f R Ld L f C f R Ld _ vcc + i cc C c D c Q c i p C f C s L f R Ld C s C f D c i p Q c C c C s

26 Operaion Principle: [ 0, 1 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

27 Operaion Principle: [ 1, 2 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

28 Operaion Principle: [ 2, 3 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

29 Operaion Principle: [ 3, 4 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

30 Operaion Principle: [ 4, 5 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

31 Operaion Principle: [ 5, 6 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

32 Operaion Principle: [ 6, 7 ] Q c V cc I o vcs A B V Cc i p C s i M I i M (+) i Cc

33 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

34 Forward Converers wih LCD Snubber vcs B V ccm A i p i M I M (+) I M ( ) i D1 v cc V ccm V ccm i Lc

35 Zero-Volage-Transiion Forward Converer Q c V ccm v cs 2 B A i p i M I M (+) I M ( ) i D1 V ccm v cc 2 i Lc

36 1. Inroducion 2. Forward Converer wih Rese Windings 3. Dual-Swich Forward Converer 4. Forward Converer wih RCD Snubber 5. Forward Converer wih Acive Clamp Rese 6. Oher Magneic Rese Mehods 7. Summary

37 Comparison of Rese Circui Topology Volage Sress of Main Swich Swiching of Main Swich Rese Winding Dual- Swich RCD Snubber Acive Clamp Simple Simple Very Simple Simple No Simple No Simple LCD 2max max <2max <2max <2max <2max Hard- Swiching Hard- Swiching Hard- Swiching Hard- Swiching Hard- Swiching ZVT Zero-Volage- Swiching Magneic Core Unidirecional magneizaion Unidirecional magneizaion Unidirecional magneizaion Bidirecional magneizaion Unidirecional magneizaion Unidirecional magneizaion Duy Cycle < 0.5 < 0.5 > 0.5 > 0.5 > 0.5 > 0.5 Efficiency No so high high low High No so high High Inpu Volage Range Narrow Narrow Wide Wide Wide Wide

38 Thanks for your aenion! Quesions? / Answer!