In the power system, due to the multiple outgoing lines and frequent operations on the medium and low voltage busbars, the distance between the three-phase conductor lines is relatively close to the ground, making them vulnerable to small animal hazards. The manufacturing quality of equipment is worse than that of high-voltage equipment, and the insulation aging and mechanical wear of equipment are affected by harsh operating conditions, changes in system operating conditions, and human operation errors. As a result, the probability of failure on medium and low voltage busbars is much higher than that of high and ultra-high voltage busbars.
However, for a long time, people have not paid enough attention to the protection of medium and low voltage busbars. Most of them rely on the backup overcurrent protection of higher-level components (such as transformers) to cut off short-circuit faults in busbars, resulting in long fault removal time, often causing the fault to develop and expand, resulting in huge economic losses. According to reports, hundreds of medium voltage handcart cabinets in China's power system are burned every year. The main reason for this is the lack of specialized protection for medium and low voltage busbars, which resulted in the failure to quickly cut off faults.

In recent years, with the increasing attention to the safety issues of electrical equipment, in order to ensure the safe operation of transformers and busbar switchgear, and in accordance with the requirements of relay protection speed, there is an urgent need for a safety monitoring system for the prevention and control of arc light on medium and low voltage busbars.
In this context, our company has absorbed advanced foreign technology and independently developed a series of HNDH-K series arc multifunctional online monitoring system products with advanced technology, strong applicability, and high reliability, based on industry testing and protection function configuration regulations. The system adopts the dual criteria principle of arc light ultraviolet detection and overcurrent detection, and has the characteristics of fast action speed (within 10ms of device outlet time, and controllable fault removal time within 85ms), high reliability (fiber optic ultraviolet sensing technology, good anti-interference ability, low probability of misoperation), etc. At the same time, the products of busbar arc protection and feeder arc protection (only cutting off the power supply of the main body, effectively controlling the power outage range) can be used in combination, effectively putting equipment and personnel safety first, minimizing accident losses, and creating conditions for rapid repair of equipment and restoration of power supply.