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Mr. Sebastian Webel
Mr. Sebastian Webel


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Pictures of the Future
The Magazine for Research and Innovation

Innovations: Inventor of the Year 2016 - Dr. Benno Weis

Innovative Power Electronics for Sophisticated Motors

Dr. Benno Weis of Siemens Digital Factory, Erlangen, holds 149 inventions and 88 individual patents which relate to control of power semiconductors and drive engineering.

To be successful when it comes to inventing, it is not necessary to start as a child. Benno Weis of Digital Factory in Erlangen only became enthusiastic about power electronics as a university student and at work. And then he could hardly be held back. For his many inventions, for example relating to control of high-frequency milling machines, he has won an award as Inventor of the Year 2016 in the Lifetime Achievement category.

“Maybe it was an advantage that I started tinkering with electronics so late,” says Weis upon reflection. “Many of my fellow students had done that so often that they were a bit bored.” Initially, he was unsure what to do after qualifying to study at university. He decided to study electrical engineering only after receiving vocational advice. But he already knew that his skills lay primarily in the fields of mathematics and science.

His motivation is of a general nature: “I want to solve problems. That’s what I like doing,” says Benno Weis. He never sets out to invent something specific. “That doesn’t work. Inventions simply occur to you.” His innovations relate to electronic circuits and drive engineering, without which high-tech motors would be inconceivable. In the same way as cars are not always driven at the same rpm, electric motors have to be controlled with modern power electronics.

New types of motors need innovative controllers. For example, industry wanted a high-speed motor for high-frequency milling machines to be able to make large parts like aircraft components or rotor blades for wind turbines. With conventional solutions, it was not possible to control a drive running at such a high speed. “That would have required extreme cooling of the motor at great expense,” Weis explains. Siemens had already developed the controller for this motor as well as the filter between the rapidly rotating machine and the inverter.

However, the high rotational speed resulted in a very small gap between the frequency of the motor and the switching frequency of the semiconductors in the controller, so the filter between the motor and the inverter had to be attenuated. “In the classic solution, however, that causes very high energy losses. I therefore devised a concept in which this energy is made available to the motor again.” Without this invention, filter attenuation would have been much greater and more expensive, and would waste energy. This drive concept is already in use in conjunction with the Sinamics converter. “This isn’t a solution that will be sold in millions but it gives Siemens leading-edge technology and enables the company to handle such machines,” says Weis

“Energy-saving solutions must make financial sense to be accepted.”

With 149 inventions and 88 individual patents in 98 patent families, Weis has made a major contribution to the evolution of power electronics. “I have improved the control of power semiconductors with many inventions,” he points out. Electronic controllers for motors are dearer than classic products but they can control drives in a more efficient and consequently more eco-friendly manner. “It is very important for us to come up with solutions that make financial sense to ensure that electronic controllers are accepted,” Weis explains. This is comparable to the choice between environmentally friendly LED lighting and low-efficiency incandescent bulbs. Consumers will only buy the LED solution if it costs less in total than the old solution.

As a member of a variety of standardization bodies, Benno Weis is often in contact with developers from other companies. This exchange of information is important for Siemens because the course is set here for the industry standards of the future. This means Weis has to go on many business trips, giving him the opportunity to pursue his penchant for new languages like he did when he was still at school. In addition to his very good skills in English and French, Benno Weis can converse in Portuguese and Italian. How good for Siemens that he ended up deciding on becoming an electrical engineer after all.

Katrin Nikolaus