Climate Change – Global WarmingDesign and Testing of a 250 kW Medium-Speed Brushless DFIG
Peter Tavner
Brushless DFIG Benefits
The Brushless DFIG proposition is to develop from the highly successful cost-effective DFIG WT drivetrain a brushless version that:
Reduces WT drivetrain OPEX costs by:
Raising generator reliability by eliminating brush-gear and slip-rings;
Raising drivetrain reliability by moving to medium speed from high speed, eliminating at least one gearbox stage;
Reduces WT drivetrain CAPEX costs by:
BDFIG retaining the DFIG benefit of a partially-rated Converter;
Lowering weight by moving to a medium speed drivetrain with a BDFIG and 2-stage gearbox;
BDFIG gains improved Grid Code ride-through performance over the DFIG, delivering lower Converter costs.
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Converter controls
Real power
Reactive power
Synchronous speed
2003 – 6 kW machine at Durham University
2002 – 7.5 kW machine at Cambridge University
2008 – 20 kW machine installed into a 20 kW Wind Turbine
2011 – 250 kW machine built and successfully tested
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Rated power
Hub height
Rotor diameter
Frame size
loading, winding currents
Dynamic and LVRT performance
Current and flux densities,
Initial specification
Final design
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Measured torque
Simulated torque
Measured PW and CW currents
Simulated PW and CW currents
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Grid
fault
hardware
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Grid
fault
hardware
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Measured grid voltage
Measured converter current
Total generated power
Brushless DFIG has been steadily developed
Design is fully understood and scalable
250 kW Brushless DFIG believed to be the largest in existence
Performance as expected – efficiency high
Excellent LVRT performance demonstrated
The team currently designing Multi-MW systems to be fitted in wind turbines
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