1. A review of power converter topologies for wind generators
陳昱希

2. Outline
Introduction
PMSG
DFIG IG SG
Conclusion

3. Introduction
This paper provides a comprehensive review of past and present converter topologies applicable to PMSG, IG, SG and DFIG. The many different generator–converter combinations are compared on the basis of topology, cost, efficiency, and control complexity.

4. PMSG Thyristor supply-side inverter
Hard-switching supply-side inverter
Intermediate DC/DC converter stage

5. Thyristor supply-side inverter
Advantages : lower device cost and higher available power rating than hard-switched inverters.
Disadvantages : need for an active compensator for the reactive power demand and harmonic distortion
created
Continuous control of the inverter firing angle, regulating turbine speed through the DC-link voltage.

6. Hard-switching supply-side inverter
Control methods:
Power mapping technique
Using a derivative control on the stator frequency (55–61%)
MPPT with wind prediction control (56–63%))

7. Intermediate DC/DC converter stage
Maintains appropriate inverter-side DC-voltage
Allows for selective harmonic elimination
Inverter no longer needs to control DC-voltage, and has more flexible control.

8. DFIG Static Kramer drive methods Back-to-back PWM converters
Matrix converter

9. Static Kramer drive
This converter provides a suitable compromise between conversion efficiency and torque oscillation smoothing.

10. Back-to-back PWM converters
Control methods:
Vector control of rotor and supply side space vector modulation
PWM MPPT space vector control

11. Matrix converter
Advantages : The converter requires no bulky energy storage or DC-link and control is performed on just one converter.

12. IG
The advantages of fuzzy logic control are parameter insensitivity, fast convergence and acceptance of noisy and inaccurate signals.

13. SG
Small wind energy conversion system Large system SG SG

14. Conclusion
PMSG offer the highest efficiency and are self-exciting machines and are therefore suitable for small-scale designs.
DFIG offers a vast reduction in converter size however they are susceptible to grid disturbances since their stator windings are directly connected to the grid.
SG allows for independent control of both real and reactive power
IG are relatively inexpensive and robust however, they require external excitation circuitry and reactive power from the grid.

15. Conclusion
The cost of the overall system increases as the complexity of the power electronic converter increases .
The complexity of the controller design also affects cost; for example, the use of MPPT techniques would cost more than a simple lookup table method.

17. Thanks for your listening