There are more and more medium and low voltage switch cabinets in the distribution system. Due to the complex environment, technical equipment failure and human factors, low and medium voltage buses are easy to cause bus short circuit, which has a great potential safety hazard.
When the bus fails, the backup protection of the transformer is used to remove the fault on the bus, which can not be solved at the exact time of the fault, and the probability of equipment damage increases, which will lead to burnout in serious cases. It is reported that more than 200 switchgears in China's power supply system are burned every year, and short-term accidents of switchgears often occur, sometimes even cause more serious power grid accidents.
The main action of arc protection is based on two different factors, arc and current increment. The arc protection device used in coal mine provides fast protection for medium and low voltage buses in substations, power plants and industrial enterprises. When the arc short circuit occurs, the arc short circuit in the area covered by the arc sensor can be quickly located, the arc protection system can act quickly, cut off the fault current, and greatly reduce the damage of arc to equipment and personnel. Arc protection device through the combination of different plug-ins, combined with the actual application of the power supply system, to form a load actual demand protection system.
The arc light protection device can also realize the all-round collection of current signal, and then complete the protection of arc light and short circuit device, alarm of current transformer disconnection, sensor abnormality, device hard board fault, measurement and control, and information protection functions. When a fault occurs, it can accurately locate the fault point, provide the setting of trip matrix at the trip exit, trip the relevant circuit breakers, realize the regional protection, and greatly reduce the scope of power failure. It has strong electromagnetic compatibility, convenient debugging and maintenance, friendly man-machine interface, convenient field installation and testing function.
