Topologies, generalized designs, passive and active damping methods of switching ripple filters for voltage source inverter: A comprehensive review

Switching ripple filters (SRF) is one of the significant part of grid connected voltage source converters (VSC) that have been a backbone of the most of renewable energy systems for the last decade. SRFs have two main features for the grid connected VSC systems. One of these is to maintain a coupling connection and integration between grid and VSC. The other one is to prevent the penetration of switching ripple currents to the grid by filtering them. Several SRF topologies named as L, LC, LCL and LLCL type are presented in literature. In order to maintain effective switching ripple filtering, higher order SRF topologies are developed. However, these high order SRFs have resonance problems. To overcome resonance problems of higher order SRFs, passive and active damping methods are applied to SRFs. This paper presents a comprehensive review of SRFs used in grid connected VSCs. In the scope of this paper, the characteristics and the design procedures of SRFs are investigated. Also, both passive and active damping methods applied to the higher order SRFs are classified in detail with the latest studies presented in literature.