High-voltage cable cross interconnection loop resistance live-line detection system and method

The invention relates to a high-voltage cable cross interconnection loop resistance live-line detection system and method. The system comprises a current injection module which injects a direct current into any two phases of metal sleeves of a three-phase cable of a high-voltage cable cross interconnection loop at one side of a cross interconnection box to form a current loop; a current and voltage acquisition module, used for testing the magnitude of the injection current and the voltage difference between two-phase injection points forming a current loop; a loop direct current detection module, used for detecting the magnitude of direct current in a three-phase cable metal sleeve on the other side of the cross interconnection box when the direct current is injected; and a central processing unit, used for controlling the switching of the three-phase loop injected by the current injection module and calculating the loop resistance of the three-phase cable cross interconnection loop before and after the direc