Power Oscillation Damping from VSC-HVDC Connected Offshore Wind Farms using DC Link Braking Chopper

This paper presents a comprehensive study of power oscillation damping (POD) in voltage source converter-based high-voltage direct current (VSC-HVDC) connected offshore wind farms (OWFs) using a DC link braking chopper. The equations and control concepts of the VSC-HVDC model are explained. A DC chopper-based fault ride-through (FRT) control strategy for onshore faults is described. Based on the FRT control concept, a novel DC chopper-based POD control strategy is presented. The aim of the control is to improve the damping ratio of both local and inter-area oscillations using the structure of a power system stabilizer (PSS). Modal analysis, small-signal damping torque analysis, and time-domain analysis are performed to evaluate the effectiveness of the proposed strategy. Case studies are conducted on the Single Machine Infinite Bus (SMIB) and the IEEE 39 bus system. The simulation results demonstrate the effectiveness of the proposed controller in damping both local and inter-area oscillation modes. The controller effectively reduces the oscillation magnitudes, resulting in improved system stability and responses.