In recent years, in order to effectively suppress the damage of the low-voltage busbar switchgear in the substation and the damage of the main transformer caused by the failure of the busbar and the circuit breaker, more and more low-voltage switch cabinets in the substation are equipped with arc protection. The arc protection device can quickly remove the fault point to ensure the safe and stable operation of the system.
The power supply and distribution system suffers from the intrusion of induced lightning and causes various short-circuit accidents. Various accidents caused by human misoperation, personal injuries and equipment damage caused by operating overvoltages will instantaneously breakdown and short-circuit, causing explosions, burning and arcing. In the form of arc light, it will not only cause serious and devastating damage to the equipment, but also pose a direct threat to personal safety. This damage and threat is determined by the characteristics of the arc light itself.
The arc protection system uses a pressure sensor as the arc detection unit. The pressure wave is one of the effects of an arc accident in the device. It will appear 10-15 milliseconds after the arc appears. Some pressure sensors can be installed to detect pressure peaks. . When the internal pressure reaches the set value, the arc monitoring device issues an action command to control the action of the switching device. However, it is not easy to predetermine the overvoltage value generated by the arc in the cabinet.
The arc phenomenon will generate strong light radiation, so the arc light in the cabinet can be detected by the arc sensor. When the arc monitoring system detects a fault, it will send an action signal to the circuit breaker.
In the protection phase, the arc protection collects the current at the incoming line through dual criteria. After the busbar fails or is damaged, the input power can be cut off within 10ms to ensure that the busbar will not be burned due to arc flash problems. The safety of the power supply system will also be improved. Great improvement.
