000K  utf8
1100  $c2017
1500  eng
2050  urn:nbn:de:gbv:8-publ-16412
2051  10.1109/TPEL.2017.2779803
3000  Zhu, Rongwu
3010  Buticchi, Giampaolo
3010  Liserre, Marco
4000  Investigation on Common Mode Voltage Suppression in Smart Transformer-fed Distributed Hybrid Grids  [Zhu, Rongwu]
4209  High-frequency (HF) switching and ac-side unbalanced loads challenge smart transformer (ST)-fed hybrid grids (both ac and dc), causing common-mode (CM) voltage variations and dc-link oscillation. The HF switching introduces an HF CM voltage and the ac grid unbalanced loads introduce a fundamental frequency CM voltage in hybrid grids. The CM voltage in ST-fed distributed grids degrades the power quality, threatens the safety of the connected devices, and potentially constitutes a health risk for the operators of such devices. Therefore, this paper systematically analyzes the root causes of the ST CM voltage variations and the impacts on hybrid grids. Based on the two typical configurations (three- and four-leg converters), the performance and requirements of CM inductor filter and bypass CM filter on HF CM voltage suppression are studied in detail. By considering the CM voltage suppression and dc capacitor lifetime, a four-leg converter with improved modulation strategy and small dc bypass film capacitor is proposed. The simulation and experimental results clearly verify the feasibility and correctness of the proposed strategies.
4950  https://doi.org/10.1109/TPEL.2017.2779803$xR$3Volltext$534
4950  https://nbn-resolving.org/urn:nbn:de:gbv:8-publ-16412$xR$3Volltext$534
4961  https://macau.uni-kiel.de/receive/publ_mods_00001641
5051  621.3
5550  Common mode voltage
5550  smart transformer
5550  three-phase four-leg converter
5550  three-phase four-wire system
5550  unbalanced three-phase loads