The principle of selecting high-voltage cables for power supply lines is to ensure safe power supply, reduce costs, and have reasonable technical design. Cable selection is mainly based on the following principles:

1. Select according to duration and allowable load current. The selected cable will not heat up after working for a long time, and the heating of the cable cannot exceed its allowable long-term temperature.

2. Select according to the voltage loss of high-voltage cables. The cable at the voltage receiving end has enough voltage, and the voltage loss should be small enough to ensure the quality of power supply.

3. Choose according to economic principles. The selected cables should be able to reduce operating costs and achieve the purpose of economical power supply.

4. Select according to the mechanical strength of high voltage cable. This is mainly to avoid damage or breakage of cables due to insufficient strength during transportation or installation. Only when the strength meets the requirements can the safety of power supply be guaranteed.

5. Choose according to whether the cable is stable enough when short-circuited. When the cable is short-circuited, its allowable short-circuit temperature must not be exceeded.

Due to poor heat dissipation, high-voltage cables are easily damaged when passing a large current in a short period of time. When selecting a high-voltage cable, the stability of the cable operation during a short circuit needs to be considered. The selection of high-voltage cables is generally based on the principles of economy, voltage loss, stability in short-circuit, and whether it will heat up after long-term work. Since high-voltage cables do not move frequently, and most of them have high mechanical strength, it is generally impossible to check their mechanical strength.

There are many benefits to burying high-voltage cables in the ground. If feasible, experts have adopted it. Why should they wait for us to question it? The truth is that there is no way for high voltage cables to be buried in the ground. The reason is that an effective insulating material for voltage transmission cannot be found to make the outer sheath insulation of the wire. Therefore, the piezoelectric wire is bare and cannot be buried in the ground. If this exposed high-voltage line is buried underground, on the one hand, it will increase consumption, and on the other hand, people on the ground will be at risk of electric shock.