Grid-Current-Feedback Active Damping for LCL Resonance in GridConnected Voltage Source Converters -2015
This paper investigates active damping of LCL-filter resonance during a grid-connected voltage-supply converter with solely grid-current feedback control. Basic analysis within the s-domain shows that the proposed damping technique with a negative high-pass filter along its damping path is like adding a virtual impedance across the grid-side inductance. This added impedance is a lot of exactly represented by a series RL branch in parallel with a negative inductance. The negative inductance helps to mitigate part lag caused by time delays found in a very digitally controlled system. The mitigation of section-lag, in turn, helps to shrink the region of nonminimum-phase behavior caused by negative virtual resistance inserted unintentionally by most digitally implemented active damping techniques. The presented high-pass-filtered active damping technique with a single grid-current feedback loop is so a additional effective technique, whose systematic style within the z-domain has been developed during this paper. For verification, experimental testing has been performed with results obtained matching the theoretical expectations closely.
Did you like this research project?
To get this research project Guidelines, Training and Code... Click Here