The engineer of a power plant in Guangzhou wants to know about the arc protection device. Through the communication between our technicians and the engineer, we know the approximate scale of the power plant and the relevant protection equipment. In today's large hydropower and thermal power plants are equipped with 10kV auxiliary system. 10kV auxiliary power system provides high-power power engine for power plant, distributes auxiliary power load, and acts as the upper level of 400V auxiliary power system to protect the whole plant production power and maintain the normal operation of generator set.

According to the analysis of 10kV auxiliary system protection configuration, there are no time limit current quick break protection, time limit current quick break protection, overload alarm and so on. These traditional time gradients or protection principles based on protection coordination and blocking make the traditional protection system unable to provide fast enough protection for power equipment. In addition, the high impedance type of ground fault can delay the action time of ground fault protection, resulting in a large amount of arc energy accumulation, which causes huge personnel and economic property losses. Therefore, the configuration of arc protection with photosensitive elements is of great significance.

Due to the frequent operation, aging of equipment insulation and mechanical wear in the medium and low voltage distribution system, the risk of arc short circuit in the busbar of switch cabinet is gradually increasing. It is necessary to install arc protection system in medium and low voltage bus switch cabinet.

The arc protection device has liquid crystal display and can connect three sections of incoming line current. The arc single criterion and arc current double criterion of the system can be selected. The arc light sensor has 360 ° non dead angle shooting. The arc light sensor is installed in each compartment of the cabinet, which can realize the protection from simple to complex and selective. As a light sensing element, the arc sensor detects the sudden increase of light intensity in the event of arc fault, and transmits the analog light signal to the arc unit or directly to the main control unit. The arc unit converts the light signal into an electrical signal for comparison, filtering, coding and electro-optic conversion, and the optical fiber transmits the digital light signal to the arc expansion unit or the main control unit.