Thanks to the ideas of Per Egedal (35), Siemens’ wind turbines run very smoothly. The Dane has developed software for automatically controlling and monitoring wind turbines. Today thousands of such turbines from Siemens operate as standard with programs from the Danish inventor.

When Per Egedal gets the feeling that too much time has gone by since his last dazzling idea, he gets restless. That’s how it was at the Christmas party for the employees of Siemens Wind Power in the Danish town of Brande three years ago. Egedal was sitting next to Henrik Stiesdal, the pioneer of Danish wind power, who is the Head of Engineering and CTO at Siemens Wind Power today. “I said to him that it was about time we invented something new again,” remembers Egedal. Stiesdal pulled a piece of paper out of his jacket pocket, unfolded it, and said, “Okay, let’s go.” That was the evening they conceived the idea of controlling the load of a wind turbine so that it achieves its planned service life of 20 years. If a very strong wind is blowing, a wind turbine not only produces a lot of power but some of its components are also worn down more than expected. The invention analyzes to what extent the actual load corresponds to an optimal load profile for the overall service life of the turbine. Commands could then be issued as necessary to cut back the amount of power generated. In light winds, by contrast, the turbine could be adjusted to produce more power.

Another of Egedal’s inventions is used in a monitoring program which helps to identify damage to rotor blades at an early stage. This program analyzes the frequencies of the vibrations in the nacelle interior in order to draw conclusions about the condition of the individual rotor blades. The sensors required for this task would already be available for other functions in Siemens wind turbines, so the machines could be retrofitted with a simple software update. A corresponding monitoring system could compare the frequency analyses of three rotor blades with one another and thus recognize when one blade starts to deviate from the normal state. This would enable rapid scheduling of repairs before further components of the wind turbine suffered collateral damage. That would prevent long downtimes.

Egedal needs a few months of development time for complex programs, but he sometimes works out less complex ones over a weekend. As a child, he loved to build complicated constructions with Lego, and something of this playfulness has remained with him to this day: “Now and again, I have to invent something crazy,” he says. He developed software to control the rotors of a row of wind turbines so that they turned synchronously, because the sight of the rotors turning out of sync annoyed him. “Technically it makes no difference whatsoever, but I think it looks a lot nicer,” says Egedal. And others agree. The program in question is now being bought by wind farm operators.

Egedal’s interest in wind turbines goes back to an internship that he held at a Danish company specializing in control systems for wind turbines, during his electrical engineering studies at Herning Institute of Business Administration and Technology in Denmark. “That was the first time I had worked on the electronic control of wind turbines, and I found it so interesting that I wrote my Bachelor’s thesis on the topic,” says Egedal. In 2001, once he had finished his studies, he continued to work with control software at this company. Later, he moved to the wind turbine manufacturer Bonus, which was acquired by Siemens shortly afterward. Since then, the location in Brande has grown rapidly. Around 3,200 employees now work here for Siemens Wind Power. “We used to be 70 engineers, but now there are 800 of us,” says Egedal, who today is a team leader responsible for development in the areas of load reduction and automation. He acquired the management expertise he needed for his responsibilities at the VIA University College, where he studied from 2008 to 2010 in parallel with his job, and obtained his Bachelor’s degree in Management. Since 2008 Egedal has been responsible for innovation going from ideas to implemented products containing algorithms for the control of wind turbines and entire wind farms, as a team leader and technology manager. His team also develops sensors for the controllers and new algorithms which are used for the monitoring programs. During his ten-year career to date, Egedal has registered 51 inventions, which have resulted in the granting of three individual patents and 44 IPR families.