Silicone high-voltage cable is a kind of power cable, which refers to the power cable used to transmit between 10KV-35KV (1KV=1000V), and is mostly used in the main road of power transmission. The product implementation standard for high-voltage cables is GB12706.3-2002

   The main types of high-voltage cables are YJV cables, VV cables, YJLV cables, and VLV cables. YJV cable full name XLPE insulated PVC sheathed power cable (copper core) VV cable full name PVC insulated PVC sheathed power cable (copper core) YJLV cable full name XLPE insulated PVC sheath Aluminum core power cable VLV cable is the full name of PVC insulated PVC sheathed aluminum core power cable. Due to the excellent conductivity of copper conductor, more and more projects use copper core power cable as the main road of the power supply system, while aluminum core power cable There are fewer applications of cables, especially in the higher-voltage power system, the more copper core cables are selected.

   The components of high-voltage cables from the inside to the outside include: conductor, insulation, inner sheath, filler (armor), and outer insulation. Of course, armored high-voltage cables are mainly used for underground burying, which can resist high-intensity compression on the ground and prevent damage from other external forces.

   The common faults of electronic circuits include mechanical damage, insulation damage, insulation damp, insulation deterioration, overvoltage, cable overheating, etc. When the above-mentioned fault occurs in the line, the power supply of the faulty cable should be cut off, the fault point should be found, the fault should be inspected and analyzed, and then repair and test should be carried out. The power supply can be restored after the fault is removed.

   The most direct cause of cable failure is breakdown due to insulation degradation. Mainly include:

  A. Overload operation. Long-term overload operation will increase the temperature of the cable and age the insulation, which will cause insulation breakdown and reduce construction quality.

  B. Electrical aspects include: the cable head construction process fails to meet the requirements, the cable head is poorly sealed, moisture penetrates into the cable, and the cable insulation performance is reduced; when the cable is laid, protective measures are not taken, the protective layer is damaged, and the insulation is reduced.

c. Civil engineering: poor drainage of pipe trenches for industrial wells, long-term water soaking of cables, which damages the insulation strength; too small industrial wells, insufficient cable bending radius, and long-term damage by external squeezing force. Mainly mechanical brutal construction in municipal construction. Dig and cut the cable.

  D. Corrosion. The protective layer suffers from chemical corrosion or cable corrosion for a long time, causing the protective layer to fail and the insulation to decrease.

e. The quality of the cable itself or the cable head accessories is poor, the cable head is poorly sealed, the insulating glue is dissolved, and cracked. The resonance phenomenon in the station is the line disconnection. The line phase capacitance and the ground capacitance and the distribution transformer excitation inductance form resonance Loop to excite the ferromagnetic resonance.

Disconnection resonance In severe cases, the superposition of high frequency and fundamental frequency resonance can make the overvoltage amplitude reach 2.5 times of the phase voltage [P], which may cause the neutral point of the system to shift, and the winding and wire may have overvoltage. Insulation flashover, lightning arrester explosion, electrical equipment damage. In some cases, the phase sequence of the load transformer may be reversed, and overvoltage may be transmitted to the low-voltage side of the transformer, causing harm to the power wire.