Performance comparison of passive series R and shunt R-C damped LCL filter for grid-connected inverters

Abstract

LCL filters are widely used in distributed power-generation systems to attenuate high-frequency harmonics caused by pulse-width modulation switching of grid-connected inverters. A resonance occurs due to the series-connected reactive components. In order to damp resonance effects, active and passive damping methods are used. Lower switching frequencies are typically preferred to decrease switching power losses with high-power applications. Thus, control bandwidth of the system is limited and implementation of active damping gets harder. As a result, passive damping methods are commonly used in high-power applications. In this study, performances of two most commonly used passive damping methods which are series R damped and shunt R-C damped are analysed and compared in terms of resonance damping, grid current attenuation at high frequencies, and power losses on damping circuits.

Keywords

• invertors
• power filters
• distributed power generation
• damping
• power grids
• performance comparison
• passive series r
• grid-connected inverters
• distributed power-generation systems
• high-frequency harmonics
• pulse-width modulation
• series-connected reactive components
• resonance effects
• passive damping methods
• lower switching frequencies
• switching power losses
• high-power applications
• active damping
• resonance damping
• grid current attenuation
• high frequencies
• damping circuits
• shunt r-c damped lcl filter