Use cases
UC3 Grid forming control for hybrid AC/DC networks
HVDC transmission systems offer significant benefits for stability and control, including active and reactive power management, synthetic inertia, and harmonic reduction. However, these capabilities present technical challenges, particularly in addressing large-signal disturbances that exceed the scope of traditional small-signal stability methods.
To ensure stability in hybrid HV AC/DC networks, advanced grid-forming (GF) schemes are needed to provide synthetic inertia and handle nonlinear dynamics. In MV/LV hybrid grids, the integration of numerous DERs leads to harmonic stability issues, necessitating stability monitoring tools and harmonic mitigation schemes integrated into converter controls to counteract medium-frequency resonances.
RWTH will use advanced grid-forming control techniques and harmonic stability analysis to enhance the performance of HVDC systems. The focus will be on improving set-point tracking, inertia emulation, harmonic stability, and resonance mitigation. The proposed methods will adapt dynamically to varying grid impedance, ensuring robust and reliable operation under diverse grid conditions and topologies.
Validation of the proposed control technique will utilize data from real-world HVDC systems, such as the Attica-Crete link and other test grids, supported by experimental testing on RWTH’s advanced test bench. A simulation-based hardware-in-the-loop setup will be employed for comprehensive analysis, including transient and long-term system behaviour. These advancements aim to enhance the robustness, flexibility, and ancillary service capabilities of HVDC systems within interconnected and offshore grids.