Why does the iron tower of the high-voltage line hiss when it rains?

This kind of sound is the noise produced by corona discharge caused by air ionization near the power line. Because the air is humid in rainy days, the resistance is small compared with dry weather. When the high-voltage line discharges to the surrounding air, it will hiss, but it will not form an arc or spark.

So, when you hear a hissing sound next to the high-voltage line, don't doubt that it is discharging. But it only happens in some places where wires have burrs or telephone poles are connected, and it will not break through the air and has no influence on people or things.

Extended data:

Discharge fault detection:

High-voltage electrical equipment is an important part of power system and the core of electrical system, so it is more and more important to detect the running state of high-voltage electrical equipment and its fault diagnosis. In recent years, China's rapid development in power system, national defense system, high-speed electrified railway and other fields has put forward higher and higher requirements for the stability of electrical equipment, which has also attracted the attention of the state.

The main component material of electrical equipment is conductor or insulating material, so the insulation of electrical equipment is very important. Insulating materials are mostly organic materials, which will gradually deteriorate under the influence of high pressure and overheating for a long time, which may lead to the failure of electrical equipment and greatly shorten the service life of electrical equipment.

According to statistics, the main accident cause of transformers with 1 10kv and above is insulation performance. The accident causes are analyzed in detail, among which 43% are caused by turn-to-turn insulation and 23% by lead insulation. If high-voltage electrical equipment fails, it will often cause huge losses and the consequences are very serious.

If high-voltage electrical equipment fails, it will inevitably lead to power failure, which will bring huge losses to national production and inconvenience to people's lives. How to improve the insulation performance of electrical equipment is a common concern in recent years.

In general, the insulation performance of electrical equipment can be improved in the following two ways: on the one hand, the production process of electrical equipment can be improved, including the use of better insulation materials, more perfect and optimized structural design, and the insulation decline can be avoided to the greatest extent from the quality.

This will greatly increase the production cost, and it is impossible to change the fact that no matter how perfect the production is, the electrical equipment will gradually deteriorate. Therefore, the only way to improve the production quality is to extend the limited working time of high-voltage electrical equipment. Second, check the maintenance equipment, reduce or reduce the number of failures, and ensure the reliable operation of the equipment.