Research on identification method of abnormal grounding circulating current in single‐core AC submarine cable

Abstract The grounding circulation current of the sheath and armour of single‐core AC submarine cables is high during operation, which can easily cause insulation damage and faults. Traditional methods that only monitor the amplitude of grounding circulation current make it difficult to detect defects in the cables, so further research is needed on the mathematical mechanism and detection methods of grounding circulation current. A mathematical model for the capacitance and impedance coupling of a single‐core submarine cable was established, and the influence of factors such as active power, length of armour stripping section, armour resistivity, armour magnetic permeability and grounding resistance on the grounding circulation current was analysed. A method for identifying abnormal grounding circulation current of submarine cables based on the combination of amplitude and phase was proposed.