A Study on mutual impact between AC and DC in AC/DC hybrid distribution networks

This study analyzes the mutual impacts between AC and DC systems in hybrid distribution networks, focusing on transformer saturation and voltage fluctuations in AC power lines caused by DC-side faults. Simulations were conducted under varying grounding resistance conditions to assess their influence on system performance. The results indicate that lower grounding resistance minimizes the impact of DC faults on the AC system, while higher resistance increases voltage fluctuations. Based on the findings, an appropriate method for selecting grounding resistance was proposed. Hybrid distribution networks offer a promising solution to complement existing AC systems; however, various challenges such as harmonic penetration and operational stability must be addressed. To ensure reliable operation, electrical separation measures between AC and DC systems should be considered, even when they are operated together. This study provides valuable insights for the planning and implementation of AC/DC hybrid distribution systems.