Special Issue Editorial: Construction of High-Voltage Direct Current Architectures and Equipment Technologies for New-Type Power Systems
Authors: Editorial Board of Automation of Electric Power Systems
The construction of new-type power systems, supporting the secure transmission and efficient utilization of large-scale renewable energy, is a major strategic initiative for China's clean energy transition. With the rapid development of energy bases in the western desert and eastern deep-sea regions, the proportion of renewable energy and DC infeed capacity in sending and receiving grids has increased significantly, leading to profound changes in source-grid structure and stability characteristics. This poses new challenges to the core functions of DC transmission technology. Firstly, large-scale renewable bases often lack conventional AC support, making point-to-point DC uneconomical and AC collection schemes risky. Secondly, the interaction mechanisms among sending/receiving grids, renewables, and DC are more complex, with prominent issues such as wide-band oscillations and cascading commutation failures. Thirdly, existing DC equipment exhibits shortcomings in system performance or economy. To address these challenges, this special issue presents 17 selected papers covering DC collection and networking, system characteristics and control enhancement, and novel converter topologies. Key contributions include a land-sea integrated DC collection scheme for gigawatt-scale offshore wind, a thyristor-based DC transformer for desert renewable bases, virtual power coordination control for urban MMC-MTDC systems, active support control for flexible DC, start-stop strategies for hybrid diode-MMC systems, small-signal stability analysis of hybrid multi-infeed systems, stability enhancement using submodule energy storage, harmonic analysis of controllable current-source converters, low-frequency oscillation suppression, commutation failure prediction, and novel topologies such as hybrid LCC, three-phase asymmetric bridge-arm reuse converters, multi-port hybrid MMC, heterogeneous UHVDC with 37.5% full-bridge submodules, and capacitive partial energy transfer DC transformers. The special issue also reports the world's first RB-IGCT-based HCC demonstration. These studies provide theoretical foundations and engineering solutions for the future development of HVDC systems.
