1 / 23

Chapter 6 Thyristor Converters

Chapter 6 Thyristor Converters. Thyristor circuits and their control Line-frequency phase-controlled rectifiers and inverters line-frequency ac <-> controlled dc. Thyristor Converters. Two-quadrant conversion positive V d implies rectification negative V d implies inverter mode.

zaria
Télécharger la présentation

Chapter 6 Thyristor Converters

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 6 Thyristor Converters • Thyristor circuits and their control • Line-frequency phase-controlled rectifiers and inverters • line-frequency ac <-> controlled dc Chapter 6 Thyristor Converters

  2. Thyristor Converters • Two-quadrant conversion • positive Vd implies rectification • negative Vd implies inverter mode Chapter 6 Thyristor Converters

  3. Primitive circuits with thyristors (1) R load • The current is zero until t= • The current and voltage vd are in phase • Average voltage of load R controlled by adjusting  Chapter 6 Thyristor Converters

  4. Primitive circuits with thyristors (2) R L load • The current is zero until t= • The current lags voltage vd • At Instant 2 current becomes zero Chapter 6 Thyristor Converters

  5. Primitive circuits with thyristors (3) L Load with dc voltage Chapter 6 Thyristor Converters

  6. Thyristor Gate Triggering Delay angle  is Chapter 6 Thyristor Converters

  7. Full-Bridge Thyristor Converters (1) Chapter 6 Thyristor Converters

  8. Full-Bridge Thyristor Converters (2) • constant dc current load Chapter 6 Thyristor Converters

  9. Thyristor Converter Waveforms (1) • Assuming zero ac-side inductance • at t=0 thyristors 1,2 are triggered • At t=  thyristors 3,4 are triggered Chapter 6 Thyristor Converters

  10. Thyristor Converter Waveforms (2) Chapter 6 Thyristor Converters

  11. Thyristor Converter Waveforms (3) • The drop in the average value due to  is • The average power in the converter is • Average power becomes negative when  > 90º ; this is inverter mode • of operation Chapter 6 Thyristor Converters

  12. Inverter mode • 90º <  < 180º • average vd is a negative value Chapter 6 Thyristor Converters

  13. Average DC Output Voltage • Assuming zero ac-side inductance Chapter 6 Thyristor Converters

  14. Input Line-Current Waveform • input line current is harmonics Chapter 6 Thyristor Converters

  15. THD, Power Factor, Power • THD • Power • Power Factor PF Chapter 6 Thyristor Converters

  16. Effect of Ls • Finite ac-side inductance; constant dc output current Chapter 6 Thyristor Converters

  17. Finite ac-side inductance (1) • finite comutation interval u • during u all thyristors conduct (vd=0) Chapter 6 Thyristor Converters

  18. Finite ac-side inductance (2) Chapter 6 Thyristor Converters

  19. Input line current is • Is has a trapezoidal waveform • DPF is • The RMS value of fundamental frequency is Chapter 6 Thyristor Converters

  20. Practical Thyristor Converter • waveform for =45º • average value of vd Chapter 6 Thyristor Converters

  21. Thyristor Converter Waveforms: Discontinuous Conduction Mode • PSpice-based simulation Chapter 6 Thyristor Converters

  22. DC Voltage versus Load Current • at constant , if Id falls below a certain value, Vd increases sharply Chapter 6 Thyristor Converters

  23. Inverter mode • 90º <  < 180º • average vd is a negative value • on dc side average power <vd>Id is negative • on ac side average power VS RMS Is1 RMS cos 1 is negative Chapter 6 Thyristor Converters

More Related