1. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems C u r t i n & P U C R S Fernando Soares dos Reis, Pontifical Catholic University of Rio Grande do Sul Syed Islam and Kelvin Tan, Curtin University of Technology

2. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Table of Contents  Introduction  Objectives  Power Quality  Harmonic Characterization  The Harmonic Mitigation Schemes  Power Losses  Conclusions

3. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion SystemsINTRODUCTION Permanent magnet synchronous generators (PMSG) wind energy conversion system (WECS) using variable speed operation is being used more frequently in wind turbine application. Variable speed systems have several advantages over the traditional method of operating wind turbines, such as the reduction of mechanical stress and an increase in energy capture. To allow the variable speed operation of the PMSG WECS a conventional three-phase bridge rectifier (BR) with a bulky capacitor associated with voltage source current controlled inverter (VS-CCI) is used.Permanent magnet synchronous generators (PMSG) wind energy conversion system (WECS) using variable speed operation is being used more frequently in wind turbine application. Variable speed systems have several advantages over the traditional method of operating wind turbines, such as the reduction of mechanical stress and an increase in energy capture. To allow the variable speed operation of the PMSG WECS a conventional three-phase bridge rectifier (BR) with a bulky capacitor associated with voltage source current controlled inverter (VS-CCI) is used.

4. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion SystemsINTRODUCTION This simple scheme introduces a high intensity low frequency current harmonic content into the PMSG and consequently increases the total loses in it. Subsequently, decreases the power capability of the system. This work presents a comparative simulation study between three different approaches applied to harmonic mitigation on PMSG WECS. The studied techniques are: a) harmonic trap filters (HTF), b) single-switch three-phase boost rectifier (PFC) and c) PWM Boost Rectifier.This simple scheme introduces a high intensity low frequency current harmonic content into the PMSG and consequently increases the total loses in it. Subsequently, decreases the power capability of the system. This work presents a comparative simulation study between three different approaches applied to harmonic mitigation on PMSG WECS. The studied techniques are: a) harmonic trap filters (HTF), b) single-switch three-phase boost rectifier (PFC) and c) PWM Boost Rectifier.

5. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Turbinas de 10 a 100 kW

6. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems WECS Wind Energy Conversion System

7. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Line-commutated inverter

8. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Current controlled inverter

9. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems AC-DC Conversion

10. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Power Quality The power quality concepts are well established and Widely applied in the relationship between utility and consumer;The power quality concepts are well established and Widely applied in the relationship between utility and consumer; Because it allows the maximization of the energy resources;Because it allows the maximization of the energy resources; But these concepts were not normally applied to WECS once there are studies showing that the system efficiency is practically the some with or without harmonics in the PMSG.But these concepts were not normally applied to WECS once there are studies showing that the system efficiency is practically the some with or without harmonics in the PMSG.

11. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Characterization

12. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Characterization

13. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems

15. The Harmonic Mitigation Schemes The Harmonic Mitigation Schemes  Passive Harmonic Trap Filters (HTF)  Single-Switch Three-Phase Boost Rectifier  Three-Phase Boost type PWM Rectifier (AC-DC converter)  Active Power Filter

16. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Passive Harmonic Trap Filters (HTF)

17. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Trap Filters

18. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Using HTF for the 5 th and 7 th harmonic

19. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Using HTF for the 5 th and 7 th harmonic PMSG output current

20. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Using HTF for the 5 th and 7 th harmonic PMSG output voltage

21. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems

22. Single-Switch Three-Phase Boost Rectifier

23. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Single-Switch Three-Phase Boost Rectifier

24. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-phase PMSG output currents

25. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-phase bridge rectifier input currents

26. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG output current

27. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG output voltage

28. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-Phase Boost type PWM Rectifier

29. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-Phase Boost type PWM Rectifier

30. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-Phase Boost type PWM Rectifier IGBT + Diode current

31. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-Phase Boost type PWM Rectifier input currents

32. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG output current

33. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Power Losses  PMSG losses  Bridge Rectifier Losses  Harmonic Trap Filter Losses  Semiconductor Losses  Mechanical losses

34. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG losses reference circuit

35. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG losses

36. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG losses

37. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion SystemsConclusions In this work three well-known harmonic mitigation solutions were applied to PMSG WECS AC to DC conversion. They were the HTF, the PFC and the PWM Boost Rectifier. Harmonic trap filters are easily implemented by passive components but they are normally implemented with bulk components.In this work three well-known harmonic mitigation solutions were applied to PMSG WECS AC to DC conversion. They were the HTF, the PFC and the PWM Boost Rectifier. Harmonic trap filters are easily implemented by passive components but they are normally implemented with bulk components.

38. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Notwithstanding the HTF had presented the good THD results they are not the best solution once they are a matched solution for a specific operation point (wind speed and output power). The losses study also has demonstrated that the PMSG efficiency (η) remains practically constant and the system η is the lowest when the HTF are used.Notwithstanding the HTF had presented the good THD results they are not the best solution once they are a matched solution for a specific operation point (wind speed and output power). The losses study also has demonstrated that the PMSG efficiency (η) remains practically constant and the system η is the lowest when the HTF are used. Conclusions

39. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems For these reasons, it is not a recommended way out to obtain harmonic mitigation on PMSG WECS. On the other hand, the single-switch three-phase boost rectifier has presented encouraged results. Such as: low current and voltage THD, simple power topology and control circuit, can work in all wind conditions and presents a real reduction of the PMSG total losses.For these reasons, it is not a recommended way out to obtain harmonic mitigation on PMSG WECS. On the other hand, the single-switch three-phase boost rectifier has presented encouraged results. Such as: low current and voltage THD, simple power topology and control circuit, can work in all wind conditions and presents a real reduction of the PMSG total losses. Conclusions

40. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Which allow expecting an increasing in the PMSG lifetime without reduction of the power capability. The main drawbacks of this topology are a) the conduction losses in the BR diodes and switch Q1 since the high RMS current value caused by the DCM operation and b) the high output voltage 1 kV. Both problems could be minimized using proper diodes and switch like IGBT.Which allow expecting an increasing in the PMSG lifetime without reduction of the power capability. The main drawbacks of this topology are a) the conduction losses in the BR diodes and switch Q1 since the high RMS current value caused by the DCM operation and b) the high output voltage 1 kV. Both problems could be minimized using proper diodes and switch like IGBT. Conclusions

41. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems The PWM rectifier was studied once with this complex converter is possible to obtain ideal PF and THD. But the losses study has show results very closed to that obtained with the Single Switch Boost Converter. The main advantage is that with this converter is possible to work with output voltages around 600V in spite of 1000V.The PWM rectifier was studied once with this complex converter is possible to obtain ideal PF and THD. But the losses study has show results very closed to that obtained with the Single Switch Boost Converter. The main advantage is that with this converter is possible to work with output voltages around 600V in spite of 1000V. Conclusions

42. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems

50. 2.4 MW Power Plant in the Northest

51. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems 4.8 MW Power Plant in the South (8 x 600 kW)

52. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems 5.0 MW Power Plant in the Northest 10 x 500 kW

53. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems THANK YOU! It was a pleasure be here!It was a pleasure be here!

54. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems Three-Phase Boost type PWM Rectifier line to line voltage

55. Harmonic Mitigation in Wind Turbine Energy Conversion Systems Harmonic Mitigation in Wind Turbine Energy Conversion Systems PMSG output voltage