High-voltage cable grounding circulation means that when the cable is working normally, the current passing through the cable will generate a magnetic field, and the magnetic field will be on the cable sheath. A potential is induced. Ground currents are generated when a loop is formed between the sheath and the ground. Generally speaking, if the grounding current is too high, it will affect the normal operation of the cable and directly affect the service life of the cable.

1. Contact resistance of high-voltage cables. This is mainly due to poor cable contact, which increases contact resistance and reduces ground loops. At this time, for the other two phases, their ground currents will not necessarily decrease. Therefore, the ground current does not necessarily decrease as the contact resistance increases.

Second, the grounding resistance of high-voltage cables. Generally speaking, when the grounding resistance continues to increase, the grounding point of the cable will be in poor contact and the cable will be damaged.

Third, the grounding method of high-voltage cables. Our common cable grounding methods are single-ended, double-ended and cross-grounded. For long-distance high-voltage cables, grounding by means of cross-connection can effectively reduce grounding circulation.

Fourth, the length, arrangement and distance of high-voltage cables will affect the ground circulation.

Analysis of abnormal ground loop;

1. When the high-voltage cable adopts a certain grounding method, the commutation fails, which will cause the cable to lose current in one direction. The ground current will increase, affecting the normal operation of the cable.

Second, the high-voltage cable water enters the grounding box, resulting in a small grounding resistance inside the box, which is equivalent to grounding outside the box. If there is water in the box for a long time, the ground current may reach hundreds of amps at this time, which will suddenly increase the current on the sheath, resulting in a rapid increase in the current inside the cable.

Third, the length of the ground wire for the cross-connection of high-voltage cables is generally more than one kilometer. Once the cable of the same axis is disconnected, the voltage at the disconnection will reach hundreds of volts, posing a threat to the safety of the line.