DC Impedance Model of MMC Considering Capacitor Voltage and Circulating Current Dynamics

Conference · Tue Oct 01 04:00:00 EDT 2019 · IEEE Energy Conversion Congress and Exposition (ECCE)

DOI:https://doi.org/10.1109/ECCE.2019.8912606· OSTI ID:1761734

Kong, Le ^[1]; Wang, Shuyao ^[1]; Praisuwanna, Nattapat ^[1]; Zhang, Shuoting ^[1]; Qiao, Liang ^[1]; Wang, Fei ^[2]; Tolbert, Leon ^[2]

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1. Univ. of Tennessee, Knoxville, TN (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

The modular multilevel converter (MMC) is regarded as a competitive choice for future dc grids at high and medium voltage levels. To study the dc grid stability, a few MMC dc impedance models have been proposed, but their accuracy is limited by the assumption of ideal submodule voltage or neglecting the circulating current control. In this paper, a more accurate MMC dc impedance model is developed considering both the submodule capacitor voltage and circulating current dynamics. Simulation and experiment results indicate that the developed model matches with the actual MMC better than state-of-art models and can predict the dc system stability correctly.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1761734
• Conference Information: Journal Name: IEEE Energy Conversion Congress and Exposition (ECCE) Journal Volume: 2019
• Country of Publication: United States
• Language: English