Analysis and Parameter Design of Passive Damping LCLLC Filter

The traditional LCL filter and its improvement topologies do not have an acceptable harmonic attenuation characteristic in the different frequency bands of active power filter output waveform. The paper presents a novel passive damping output filter named LCLLC filter which combines the advantages of both LCL and LLCL filter. The LCLLC filter inserts a small inductor and capacitor branch can strongly eliminate the harmonic currents around switching frequency and at the same time it improves the deficiency of LLCL filter in the high-frequency range. To demonstrate the performance of the LCLLC filter, we also provided the comparative analysis of the LCL and LLCL filter.. Simulation in MATLAB/Simulink is presented to verify the theoretical analysis.