Weimin Wu, Min Huang, Yunjie Sun, Xiongfei Wang, F. Blaabjerg
{"title":"A composite passive damping method of the LLCL-filter based grid-tied inverter","authors":"Weimin Wu, Min Huang, Yunjie Sun, Xiongfei Wang, F. Blaabjerg","doi":"10.1109/PEDG.2012.6254087","DOIUrl":null,"url":null,"abstract":"This paper investigates the maximum and the minimum gain of the proportional resonant based grid current controller for a grid-tied inverter with a passive damped high-order power filter. It is found that the choice of the controller gain is limited to the local maximum amplitude determined by Q-factor around the characteristic frequency of the filter and grid impedance. To obtain the Q-factor of a high-order system, an equivalent circuit analysis method is proposed and illustrated through several classical passive damped LCL- and LLCL-filters. It is shown that both the RC parallel damper that is in parallel with the capacitor of the LCL-filter or with the Lf-Cf resonant circuit of the LLCL-filter, and the RL series damper in series with the grid-side inductor have their own application limits. Thus, a composite passive damped LLCL-filter for the grid-tied inverter is proposed, which can effectively suppress the possible resonance in case that the grid impedance varies in a wide range. Simulation results are good agreement with the theoretical analysis.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"26","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/PEDG.2012.6254087","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 26
Abstract
This paper investigates the maximum and the minimum gain of the proportional resonant based grid current controller for a grid-tied inverter with a passive damped high-order power filter. It is found that the choice of the controller gain is limited to the local maximum amplitude determined by Q-factor around the characteristic frequency of the filter and grid impedance. To obtain the Q-factor of a high-order system, an equivalent circuit analysis method is proposed and illustrated through several classical passive damped LCL- and LLCL-filters. It is shown that both the RC parallel damper that is in parallel with the capacitor of the LCL-filter or with the Lf-Cf resonant circuit of the LLCL-filter, and the RL series damper in series with the grid-side inductor have their own application limits. Thus, a composite passive damped LLCL-filter for the grid-tied inverter is proposed, which can effectively suppress the possible resonance in case that the grid impedance varies in a wide range. Simulation results are good agreement with the theoretical analysis.