Abstract:
This paper investigates the active damping of LCL
filter resonance in a grid connected voltage source inverter. The
active damping realized using feedback of inverter side current is
considered for analysis. A detailed study showing suitable choice
of resistor required for resonance damping in case of the passive
and active damping methods is presented. An explicit study
showing the limitations of active damping over passive damping
for a chosen Switching and resonance frequencies has carried
out. The proposed work is simulated using MATLAB/Simulink
for the resonance frequency of 1.4kHz and switching frequency of
10KHz. Typical results are reported and analyzed. It is observed
from results that the virtual resistor introduced using active
damping technique is unlike to the passive damping after a point
of Rd values. This issue can be resolved by choosing controller
bandwidth adaptive to the changes present in value of virtual
resistor.
