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Interoperable power electronics – challenges and opportunities

Docentlecture by Associate Professor Staffan Norrga, EPE

Tid: Må 2021-04-26 kl 10.00

Plats: Zoom

Medverkande: Associate Professor Staffan Norrga

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A hundred years ago, the power grid did not rely on power electronics, or the ICT that controls it. However, currently the ways electricity is produced and used are rapidly evolving, which is made necessary by the need to decarbonize the energy system. Renewable energy sources, such as wind power and solar power use power electronic converters to connect to the grid. In addition, the electrification of the transport sector requires power electronics in the form of battery chargers and railway power supplies.

Modern power electronic converters offer tremendous possibilities for rapid and exact control of active and reactive power in different operating modes, which potentially should pave the way for improved grid reliability. However, the possibilities for unwanted interactions are also significant. Excessive emission of harmonic currents is one problem that may cause electromagnetic interference and distorted loads. A more complex issue is the interaction of the control systems of different power converters connected to the same grid. Here, the consequences can be instability and oscillations that may disrupt operation altogether.

A grid involves many independent actors owning and operating different pieces of equipment. Furthermore, the equipment is provided by different competing suppliers, which may limit the prospects for the collaboration needed to achieve interoperability. This means that interoperability is not just a technical issue, but that also IPR aspects, competition law, and government regulation need consideration.

The lecture will provide the background of the problem, including my own experiences as an engineer and a researcher in power electronics for more than 25 years. Methods for achieving and verifying interoperability will be outlined and various examples provided. In particular, an initiative to use open-source software for parts of the control and protection systems of grid-connected power converters will be described. This way all the involved stakeholders (manufacturers, users, grid operators) can have access to the software determining the behavior of the equipment.

Speaker biography:

Staffan Norrga was born in Lidingö, Sweden, in 1968. He received the M.Sc. degree in applied physics from Linköping Institute of Technology, Linköping, Sweden, in 1993 and the Ph.D. degree in electrical engineering from the Royal Institute of Technology (KTH), Stockholm, Sweden, in 2005. Between 1994 and 2011, he worked as a Development Engineer at ABB in Västerås, Sweden, in various power-electronics-related areas such as railway traction systems and converters for HVDC power transmission systems. He currently holds a position as associate professor in power electronics at KTH. His research interests include power electronics and its applications in power grids, renewables and electric vehicles. He is the inventor or co-inventor of more than 10 granted patents and has authored or co-authored more than 100 scientific papers published at international conferences or in journals.