Thread Content
In our country, during short-circuit faults in medium and low-voltage busbars, equipment damage and injuries to personnel are primarily caused by arc light. However, most medium and low-voltage busbars in our country are not equipped with rapid busbar protection; instead, only simple arc suppression devices and backup protection for transformers are used. These protections have lower intelligence levels and slower response times, which often prolongs the time required to eliminate faults. This further increases the degree of damage to the equipment, and can even lead to catastrophic failures in a chain reaction, affecting the normal operation of transformers and compromising the safe functioning of the entire power grid. The arc flash protection device is a new type of arc flash protection system that incorporates the advantages of foreign arc flash protection solutions, featuring wide applicability and high reliability. It adopts the dual-criterion principle of arc detection and overcurrent detection, featuring fast protection response speed and high reliability. The basic principle of arc protection devices is to detect arcs and overcurrent. It breaks away from the conventional criteria for protection, and takes the detection of arc light and current—two unrelated parameters—as criteria, resulting in a lower rate of false operations and higher reliability compared to other protections. The arc light acquisition unit, used in conjunction with the main control unit, is an important component of the arc flash protection system. It is primarily used to capture fault arcs, and to transmit the results of the analysis to the main control unit via optical signals. A single arc detection unit can be installed, equipped with 16 arc probes; the number of such units can be increased or decreased depending on the size of the system. The arc light collection unit is usually installed within a selected switchgear cabinet, with the selection principle being to minimize the amount of optical fibers required for that unit. By adopting the dual-criterion principle of arc detection and overcurrent detection, it features a simple principle, reliable and rapid operation, no special requirements for the primary equipment in substations, suitability for various operating modes, and the advantage that the protection does not need to be switched under different operating conditions. It represents an ideal solution for busbar protection in power plants, substations, as well as industrial and commercial distribution systems.