Unique facility puts wind turbine drivetrain packages to the test under real world operating conditions
Robust grid code compliance and superior overall performance of 3 MW electrical drivetrain package is verified by extreme full power tests
In my recent blog ‘How to increase wind turbine uptime’, we pointed out the six most important considerations and measures that should be taken to eliminate the risks associated with wind turbine converters.
One important measure is the thorough testing of the generator and converter as part of a complete electrical drivetrain package rather than as separate components. Subjecting the complete electrical drivetrain to real-world full power usage conditions verifies its performance and grid code compliance. It also simplifies turbine certification and reduces on-site testing costs.
We perform extreme full power performance testing of the entire wind turbine electrical drivetrain at a unique state-of-the-art facility within our electrical drivetrain laboratory in Helsinki, Finland. In June, this facility completed a comprehensive factory acceptance test (FAT) program for a customer on a full scale test configuration – comprising a 3.25 megawatt (MW) permanent magnet synchronous generator and a full power converter.
The full scale and full power performance tests included temperature rise test, du/dt (voltage rise), peak voltage, harmonics and measurement of the electrical drivetrain’s efficiency throughout the intended wind turbine operational speed range. We also conducted comprehensive grid code compliance tests covering over 50 different fault conditions, including single-phase-to-ground and phase-to-phase failures.
Electrical drivetrain testing included the ACS880 full power converter
The electrical drivetrain package on test consisted of a permanent magnet synchronous generator incorporating a patented structural design for the rotor and dual winding coil groups at the stator, and an ACS880 full power converter. The ACS880 is equipped with parallel-connected sub-converters, which can be activated or deactivated depending on the wind conditions. This increases the converter’s overall efficiency, especially at partial load (low wind conditions).
For IEC class III turbines, which are generally characterized by low wind speed, partial power operation of the turbine is predominant. If the extractable power from the wind is equal to or less than 50 percent of the turbine’s rated power it is economical to run just a single sub-converter. This means that only one sub-converter is connected on-line while the other sub-converter is connected off-line. This significantly reduces the power losses of the power converter.
The parallel connected sub-converters also provide redundancy which ensures continuous operation of the converter and enhances the availability of the turbine. Should one of the sub-converters fail, the turbine continues to operate in “partial redundant” mode and still delivers up to 50 percent of the power.
Together, the generator and ACS880 full power converter create a perfect electrical drivetrain package, optimized, but not limited, to IEC class III wind turbines. This package enables turbines to comply with even the strictest international grid code requirements, and to deliver 3 MW of high quality power into the utility grid.
Test results confirm drivetrain performance
The tests, witnessed by our customer, verified that the electrical drivetrain performs as specified and that it meets international grid code requirements. It has now been shipped to the customer and is currently being installed in their wind turbine.
Thanks to this in-house full-scale and full power testing facility we can emulate real world power system network conditions. This has enabled the development of a new well proven electrical drivetrain package with enhanced and predictable performance, taking wind turbine electrical drivetrain efficiency, reliability and availability to the next level. The facility in Helsinki is also ideal for helping to train customers to get the best out of their electrical drivetrain.
If you would like to find out more about our electrical drivetrain testing laboratory and real-time simulation tools, please contact us or visit us at EWEA in Paris, November 17 to 20, 2015 (ABB at EWEA Annual Event 2015, Stand H11). We look forward to discussing with you how we can help to reduce the LCoE (Levelized Cost of Energy) of your own wind farm.
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