Groundbreaking invention goes to the Deutsches Museum

The world's first Modular Multilevel Converter (MMC), a pioneering invention in electric power technology, is handed over to the Deutsches Museum, Munich.


(Photo © Czech/Deutsches Museum)

In the presence of the Director General of the Deutsches Museum Munich, Prof. Wolfgang M. Heckl (right), the President of the Bundeswehr University Munich, Prof. Eva-Maria Kern (left), and the curator Dr. Frank Dittmann, Prof. Rainer Marquardt, Excellent Emeritus of the Bundeswehr University Munich (center), handed over one arm of the world's first Modular Multilevel Converter (MMC) from the Laboratory of High Power Electronic Systems to the Deutsches Museum on April 8, 2024.

Key component of modern electric power systems

The importance of this invention for the electronic control and conversion of electrical energy has steadily increased due to the global need to reduce greenhouse gases. Today, MMC´s are a key component of electric power systems, which enable the highly dynamic control of the power flow and the connection of renewable energy sources like offshore windfarms to our electricity grid. The technical requirements for applications in the context of the energy transition are extremely high, which is why converters have long been regarded by experts as the key technological bottleneck.

The major breakthrough came around 25 years ago with the invention and development of a new class of multilevel converters by Prof. Marquardt, which were able to meet both extreme technical and industrial requirements for the first time [1]. These include maximum reliability through structural redundancy and universal scalability up to the highest voltages and outputs of several gigawatts.

The first commercial application was a converter for the Trans-Bay cable in San Francisco [2] in 2010, which replaced a coal-fired power plant with a direct current submarine cable connection. This was followed by numerous other projects around the world that were made possible by the new technology. In future, the MMC will also enable to build large, meshed direct-current grids - as an advanced addition to existing three-phase grids - that are free from their stability problems and whose power flow can be freely controlled.

MMC is in good company at the Deutsches Museum

“The MMC is a revolutionary invention from Munich. The converter has many advantages in the long-distance transmission of large amounts of energy with high DC voltage. Prof. Marquardt brought the concept to maturity during his time at the University of the Bundeswehr Munich and realized demonstrators to prove its feasibility. We are delighted to add part of the demonstrator to the collection of the Deutsches Museum today. The MMC is in good company there - with many inventions that represent a revolution in their respective fields,” says Prof. Wolfgang M. Heckl, Director General of the Deutsches Museum.


[1] A. Lesnicar and R. Marquardt, "An innovative modular multilevel converter topology suitable for a wide power range," in Proc. IEEE Bologna Power Tech Conf., Bologna, Italy, 2003, doi: 10.1109/PTC.2003.1304403.
[2] T. Westerweller, K. Friedrich, U. Armonies, A. Orini, D. Parquet, and S. Wehn, "Trans Bay cable – world's first HVDC system using multilevel voltage-sourced converter," B4 Study Committee Session, B4-101, CIGRÉ, Paris, France, 2010.