3. External protection layer issue. In medium and high voltage power grids, the application of power cables is becoming increasingly widespread. The outer sheath of power cables is the first line of defense to protect cables, and its integrity directly affects the safety of the internal structure and the service life of the cables

Measures to prevent power cable faults: 1. From the beginning of the design, select cables that meet their voltage levels, fully understand the Earthing system used by the cables, and avoid the cables working under long-term overvoltage conditions. The selection of outer sheath should meet the requirements of service life and usage environment, and the selection of cable sheath protector should meet the principle of reliable passage of grounding current without damage when the protector is relatively grounded. 2. The selection of cable routing should avoid the influence of external environment, such as overheating, corrosion, external force damage, etc. And avoid the influence of internal factors, such as excessive concentration of cable laying, which may lead to timely diffusion of heat and cause overheating. In addition, to avoid simultaneous damage to cable paths, it is not recommended to lay dual circuit power supply cable paths in pipelines along the same path, resulting in large-scale power outages. 3. Strengthen personnel training, and ensure that cable head production personnel hold certificates to work. And necessary business qualifications and technical assessments must be conducted. 4. By utilizing advanced online monitoring technologies such as online fiber optic temperature measurement technology, line monitoring technology, and online partial discharge detection technology, the outer sheath circulation is utilized to strengthen real-time online operation monitoring of cables, identify hidden dangers in advance, and avoid power outage accidents