High-voltage fuse: the key guardian of high-voltage circuits

High-voltage fuses are specially used in high-voltage power systems. Their working principle is similar to that of ordinary fuses, but they have unique characteristics. They are mainly composed of metal melts, supporting insulators and connecting terminals. When the high-voltage circuit is running normally, the current passes through the high-voltage fuse stably, and the metal melt can withstand the long-term action of the rated current and remain intact. However, once an abnormal overcurrent occurs in the circuit, such as a phase-to-phase short circuit or a ground short circuit caused by insulation damage, the current will increase sharply. At this time, according to Joule's law, the metal melt will heat up rapidly under the high heat generated by the large current. Due to its special material and design, the metal melt of the high-voltage fuse will quickly melt when it reaches the predetermined melting temperature, thereby cutting off the high-voltage circuit, effectively preventing the continuous flow of the fault current, preventing the fault from further expanding, and ensuring the basic safety architecture of the entire high-voltage power system.

1.The core significance of high-voltage fuses in power transmission

Ensuring the stability of power transmission

In the high-voltage power transmission network, electric energy needs to be transmitted over long distances and in large capacities. High-voltage fuses are installed at key nodes of the transmission line, like loyal guards. When the transmission line encounters an unexpected situation such as lightning strikes, tree branches touching, etc., which causes instantaneous overcurrent, the high-voltage fuse can respond quickly and blow in time to isolate the fault area. This avoids the impact of fault current on the entire transmission line, prevents power outages caused by local faults, ensures that electricity can be continuously and stably transmitted to various substations and the final power consumption area, maintains the reliability and continuity of power supply, and provides a solid power guarantee for the normal operation of social production and life.

Protect expensive high-voltage equipment

High-voltage substations are equipped with many expensive and technically complex high-voltage equipment, such as transformers,fuse cutout, circuit breakers, etc. These equipment play a key role in the normal operation of the power system. High-voltage fuses play an important role in the protection circuits of the incoming and outgoing lines of the substation and various internal equipment. Without the effective protection of high-voltage fuses, when a short-circuit fault occurs in the high-voltage circuit, the strong short-circuit current will impact these high-voltage equipment without hindrance, which may cause serious damage such as burning of the equipment winding and insulation breakdown. Not only will it cost a huge amount of money to repair or replace the equipment, but it will also cause long-term power outages, affecting the power consumption of a large area of ​​users. High-voltage fuses can quickly cut off the current when a fault occurs, minimize the damage to high-voltage equipment caused by the fault, extend the service life of the equipment, and reduce the operation and maintenance costs of the power system.

2.The unique advantages of high-voltage fuses in the power grid safety system

Fast fault response capability

Faults in high-voltage circuits often need to be handled in a very short time, otherwise they may trigger a chain reaction and cause the power grid to collapse. High-voltage fuses have a fast fusing characteristic and can respond to overcurrent faults and cut off the circuit within milliseconds. Compared with some complex relay protection devices, it does not need to rely on external power supply and complex control logic, but relies entirely on its own physical fusing mechanism. It can start the protection action at the moment the fault occurs, greatly shortening the existence time of the fault current, reducing the impact and damage range of the fault on the power grid, and gaining valuable time for subsequent fault investigation and repair.

Simple and reliable structure

The structure of high-voltage fuse is relatively simple, mainly composed of metal melt and insulating support components. This simple structure makes it highly reliable and not easily affected by factors such as electromagnetic interference and ambient temperature changes. In the complex electromagnetic environment of high-voltage power system and harsh natural environment, such as strong electric field, high humidity, low temperature, etc., high-voltage fuse can still work stably. Moreover, its installation and maintenance are relatively simple, and no professional technicians are required to perform complex debugging and calibration, which reduces the difficulty and cost of operation and maintenance of power system, and plays an irreplaceable role in the long-term stable operation of power grid.

3.Potential value of high-voltage fuse to the intelligent development of power system

As the power system develops towards intelligence, the role of high-voltage fuse has not been weakened, but has been given new missions and potential value. Although there are various advanced monitoring, control and protection equipment in smart grids, high-voltage fuse as the most basic overcurrent protection element, its function of quickly cutting off the fault circuit is still the last line of defense for the safety of the entire power grid. At the same time, by combining with intelligent sensors, real-time monitoring of the working status of high-voltage fuse can be achieved, such as monitoring whether it is blown, temperature changes of the fuse, etc., and transmitting this information to the monitoring center of the power grid. This not only helps to promptly detect and handle circuit faults, but also provides data support for the intelligent dispatch and optimized operation of the power grid, further improving the intelligence level and overall operating efficiency of the power system.