Wind power control systems go to (temperature) extremes

High-temperature uninterruptible power supply helps Danish control system designers handle Mongolian temperatures up to 55 ºC (131 ºF).


The most important task in wind turbine control is blade pitch regulation and braking during short term grid failure or utility loss. Source: kk-electronic a/s

The most important task in wind turbine control is blade pitch regulation and braking during short term grid failure or utility loss. Source: kk-electronic a/s

Wind turbines have been in use for many decades, but the combination of rising fuel costs, tighter company budgets, and environmental initiatives to use renewable/greener energy sources is spurring greater-than-ever interest in them. Control systems are a key component in wind turbines, and so is design for extreme conditions.

kk-electronic a/s has been developing and producing complete turnkey wind turbine control systems for leading wind turbine manufacturers for nearly three decades. Systems from this Danish company currently can be found in more than 15,000 wind turbines operating around the world — from major U.S. wind farms like King Mountain in Texas to established offshore wind farms like ones in Middelgrunden, Copenhagen, and Nysted, Denmark.

kk-electronic’s control systems for wind turbines range from simple control elements to state-of-the-art complex control systems that have the high reliability needed for what are frequently rough-weather conditions. Six months may go by before scheduled maintenance is conducted on components, which are mounted at the top of a 450-ft. tower and are subjected to temperature extremes, lightning strikes, and other hazards. So, systems include built-in remote monitoring and reporting that acknowledge the difficulty of on-site inspection.

Let’s first take a look at the wide range of electrical and electronic components that ensure the safe and reliable generation of electricity from a wind turbine. These include:

  • Main computer, I/O modules, relays, and components for turbine monitoring and control;

  • Continuous condition monitoring of wind turbine operation;

  • Hub computer to control blade pitch;

  • Frequency converter, yaw motor protection, etc. for the soft yaw system;

  • Terminal box in the top of the tower, which connects the aluminum cables in the tower to the flexible copper cables from the generator;

  • Power converter (full or dual fed), filter, phase compensation, etc.;

  • High-temperature uninterruptible power supply, I/O modules, interface computer, operating panel, network components, and SCADA interface;

  • High voltage, medium voltage, and low voltage distribution boards;

  • Main circuit breaker, grid connection, power unit, etc., plus power quality analyzers;

  • Anemometers, wind vanes, aviation warning lights; and

  • Elements for supply of crane, hatch, heating, cooling, smoke detection, etc.


The most important task in wind turbine  control is blade pitch regulation and braking during short term grid  failure or utility loss. Source: kk-electronic a/s

A challenge to wind turbine control system designers is the extreme temperatures and temperature swings that turbine facilities can be subjected to. The control systems (and the turbine itself) must be able to continue working in these conditions. Qianwei Chongqing Qianwei Instrument & Meter Factory of China was looking for a wind turbine control system that could provide the uptime numbers needed to achieve a return on investment within their turbines’ targeted timeframe. Qianwei evaluated wind turbine controls from several vendors, and selected kk-electronic.

kk-electronic has since entered into a joint venture with Qianwei. The new company, kk-Qianwei, will market and manufacture control panels. kk-electronic’s contribution to the joint venture includes its newest wind turbine control system, named “Commander,” which is a turnkey solution for wind turbine control. This system consists of a combination of pre-engineered control elements with modular add-ons that can be implemented rapidly. kk-electronic also has completed a new $2 million plant in Ikast, Denmark, for the production of electronic control circuits.

The most important task in wind turbine  control is blade pitch regulation and braking during short term grid  failure or utility loss. Source: kk-electronic a/s

Blading braking

The most important task in wind turbine control is continuous control of wind turbine blade pitch and braking during short-term grid failure or utility loss. This is essential for safe operation, since failure to assure this control can result in mechanical stress of the drive train and its tower, in addition to the possibility of loss of life.

To stop the turbine blades from turning, the angle of every blade (pitch) is adjusted so the edges of the blades are in line with the wind; eliminating the force of wind against the blades decreases rotor speed. Next, brakes are applied to stop and hold the rotor. If the brakes are applied before the rotor speed is below allowed braking speed, the brakes will be damaged.

To eliminate single-point-of-failure in braking control, kk uses two separate control subsystems dedicated to the monitoring and control of the turbine blade pitch control and braking.

Temperature extremes

As these computers are only as reliable as their power source, kk-electronic realized that both systems needed to have their own sources of backup power, in addition to the utility power source. Engineers decided on a battery-operated uninterruptible power supply (UPS), but knew it was critical to find a high-temperature-rated UPS designed to operate in locations subjected to extremely wide temperature ranges. According to Claus Damgaard, electrical power engineer, research & development, “Our wind turbine control systems were slated to be operating in Mongolia and other remote regions in China, where the daytime temperature reaches 55

The cold problem was solved easily enough by adding heating elements to the control cabin, says Damgaard, but in the case of a utility loss, the temperature could drop to -40

“I contacted Falcon Electric while the Qianwei project was in its infancy,” explains Damgaard. “I had searched the Internet for high-temp industrial UPSs and found out that Falcon offered the only UL-rated UPS for 55

Falcon has supplied industrial UPSs for companies like GE, Siemens, and Johnson Controls. “Falcon engineer Mike Stout told me that GE had used Falcon’s UPS to power their WTCs [wind turbine controls], so I was even more confident,” says Damgaard. “More importantly, since the new Falcon SSG Series hi-temperature UPS was too deep for the tray we had designed for the UPS, Falcon accepted my request to integrate the UPS electronics only, and let kk-electronic source military-grade high-temperature batteries.

“The fact that Falcon was willing to customize its UPS, then spend time ensuring our battery pack worked with these batteries, was fantastic. In my experience, UPS companies will not even consider offering this level of customization and support, especially for a quantity of 50 or 100 units.”

kk-Qianwei is currently testing its initial joint-venture wind turbine in Mongolia, where it has been operating for several months. Damgaard says plans call for kk-Qianwei to install more than 100 additional turbines in 2010.

Information on kk-electronic a/s is available on LinkedIn.

Author Information

Renee Robbins is senior editor for Control Engineering. Reach her at .

Resources for wind energy control system design

Whitepapers, Webcasts and online links to more information are available via .


Whitepaper: A free whitepaper from Dataforth explains wind turbine operations in detail. “Extreme I/O applications and signal conditioning tips” addresses the extreme temperature and vibration issues associated with wind turbine control.


Video: Winergy Drive Systems builds specialized gearboxes for wind turbines, and claims world leadership in that industry segment with 50% of the market globally and 60% in the U.S. This short video, “The Heart of a Wind Turbine,” takes you on a tour of the Winergy Drive Systems assembly floor, showing these huge units in their final production stages.


Webcast: One issue often missing from the discussion of alternative energy initiatives such as wind power is what engineers across all manufacturing industries can learn from these industries in terms of business development and technology application. These green-energy industries may be new, but they’re leveraging a lot of tried-and-true control technologies to make them viable. Online at , you can access “Wind Energy: Control Engineering Lessons and Opportunities.” Speakers in this free webcast include Brian MacCleery, National Instruments senior product manager for renewable energy, and Javier Gutierrez, National Instruments senior product manager for control & simulation. MacCleery and Gutierrez discuss how wind turbines are manufactured and controlled, how wind turbine control teams are developing advanced control systems using embedded system platforms, and the wind energy industry’s use of hardware-in-the-loop simulations for controller testing.


No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Safer human-robot collaboration; 2017 Maintenance Survey; Digital Training; Converting your lighting system
IIoT grows up; Six ways to lower IIoT costs; Six mobile safety strategies; 2017 Salary Survey
2016 Top Plant; 2016 Best Practices on manufacturing progress, efficiency, safety
Mobility as the means to offshore innovation; Preventing another Deepwater Horizon; ROVs as subsea robots; SCADA and the radio spectrum
Future of oil and gas projects; Reservoir models; The importance of SCADA to oil and gas
Big Data and bigger solutions; Tablet technologies; SCADA developments
Automation modernization; Predictive analytics enable open connectivity; System integration success; Automation turns home brewer into brew house
Commissioning electrical systems; Designing emergency and standby generator systems; Paralleling switchgear generator systems
Natural gas for tomorrow's fleets; Colleges and universities moving to CHP; Power and steam and frozen foods

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Motion control advances and solutions can help with machine control, automated control on assembly lines, integration of robotics and automation, and machine safety.
Compressed air plays a vital role in most manufacturing plants, and availability of compressed air is crucial to a wide variety of operations.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
click me