1. Power Electronics Lecture (7) Prof. Mohammed Zeki Khedher Department of Electrical Engineering University of Jordan 1

2. Single-Phase Full-Wave Diode Rectifier Center-Tap Diode Rectifier

3. PIV of each diode = Example 3. The rectifier in Fig.2.8 has a purely resistive load of R Determine (a) The efficiency, (b) Form factor (c) Ripple factor (d) TUF (e) Peak inverse voltage (PIV) of diode D1 and(f) Crest factor of transformer secondary current.

4. The PIV is

5. Single-Phase Full Bridge Diode Rectifier With Resistive Load

12. Example 4 single-phase diode bridge rectfier has a purely resistive load of R=15 ohms and, VS=300 sin 314 t and unity transformer ratio. Determine (a) The efficiency, (b) Form factor, (c) Ripple factor, (d) The peak inverse voltage, (PIV) of each diode,, and, (e) Input power factor. The PIV=300V Input power factor =

16. Comparision between Single Phase Rectifiers Half wave Full wave Fullwave center-tap bridge Peak repetitive reverse voltage VRRM 3.14Vdc 3.14 Vdc 1.57 Vdc Rms input voltage per transformer leg Vs 2.22 Vdc 1.11 Vdc 1.11 Vdc Diode average current IF.AV. 1.00 Idc 0.50 Idc 0.50 Idc Diode rms current IF.RMS. 1.57 Idc 0.785 Idc 0.785 Idc Form factor of diode current IF.RMS. 1.57 1.57 1.57 Rectification ratio 0.405 0.81 0.81 Form factor 1.57 1.11 1.11 Ripple factor 1.21 0.482 0.482 Transformer rating primary VA 2.69 Pdc 1.23 Pdc 1.23 Pdc Transformer rating secondary VA 3.49 Pdc 1.75 Pdc 1.23 Pdc Output ripple frequency fr 1 fi 2 fi 2 fi

17. Multi-phase Rectifier

20. Three-Phase Half Wave Rectifier

21. ThePIV of the diodes is Example A 3-phase star rectifier is operated from 460 V 50 Hz supply at secondary side and the load  resistance is R=20. If the source inductance is negligible, determine (a) Rectification efficiency, (b) Form factor (c) Ripple factor (d) Peak inverse voltage (PIV) of each diode.

22. The PIV= V m =650.54V

23. Three-Phase Full Wave Rectifier With Resistive Load

28. Example 10 The 3-phase bridge rectifier is operated from 460 V 50 Hz supply and the load resistance is R=20ohms. If the source inductance is negligible, determine (a) The efficiency, (b) Form factor (c) Ripple factor (d) Peak inverse voltage (PIV) of each diode.

29. The PIV= V m =650.54V

30. Single phase rectifier 3 phase rectifier Performance:

31. 3-phase bridge rectifier with RL load

33. Condition for continuous load current