Heating Problems When Using the Converter Station Grounding Grid as the HVDC Grounding Electrode

To ensure the safe and stable operation of HVDC systems without grounding electrode, this paper proposes a concept of replacing the HVDC grounding electrode with the converter station's grounding grid.This paper studies the technical problems of heating problem of grounding grid.The result shows that the ground down lead can't bear DC current in a long-term, which means the ground return current utilizes the feeder cable to run into the grid.The permitted operating time when the ground return current is 3000A should be limited within 10 minutes.If an HVDC link uses bipole blocking control strategy, the research helps eliminating the HVDC grounding electrode, which will greatly save the cost.