Advanced Control Approach for Post-Fault Recovery in MTDC Networks

The integration of renewable energy sources and offshore wind farms demands robust High-Voltage Direct Current (HVDC) networks. A key challenge is mitigating post-fault oscillations during converter deblocking, which arise from interactions between converter dynamics, HVDC cables, and system nonlinearities. These oscillations can destabilize the system, extend recovery times, and disrupt grid operations. This study investigates a four-terminal Multiterminal DC (MTDC) network using a real-time simulator. An enhanced DC voltage regulation strategy is proposed, integrating a washout filter and an anti-windup mechanism within a Proportional-Integral (PI) controller. Furthermore, a meticulous parametric sensitivity analysis is performed to optimize controller parameters, achieving significant reductions in oscillations using a real-time simulator to extract valuable insights into the damping method’s effectiveness under various operating conditions.