The Modular Multilevel Converter as Universal High-Precision 3AC Voltage Source for Power Hardware-in-the-Loop Systems

Conference: PCIM Europe 2014 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
05/20/2014 - 05/22/2014 at Nürnberg, Deutschland

Proceedings: PCIM Europe 2014

Pages: 8Language: englishTyp: PDF

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Authors:
Kolb, Johannes (Schaeffler Technologies GmbH & Co. KG - SHARE at KIT, Karlsruhe, Germany)
Kammerer, Felix; Schmitt, Alexander; Gommeringer, Mario; Braun, Michael (Karlsruhe Institute of Technology (KIT) - Institute of Electrical Engineering (ETI), Germany)

Abstract:
Three-phase voltage sources are power electronic systems, which generate specific, highquality voltage waveforms for many different applications. They are used in Power Hardware-in-the-Loop (PHIL) systems for the emulation of electrical machines or grids as well as in test and measurement systems for the characterization of passive components, transformers, magnetic materials, etc. The proposed 3AC voltage source is realized by a Modular Multilevel Converter (MMC), which generates voltage waveforms with small steps due to its series-connected cells. The quality of the voltage is further improved by a small filter to eliminate harmonics in the range of the switching frequency. Measurements are performed on a low voltage MMC prototype to evaluate the precision of the voltage waveforms. A MMC in 1AC-3AC configuration, which is coupled to a medium frequency transformer, is presented to meet the requirement of a galvanically isolated power supply and to overcome the limitations at low frequency operation.