Analysis On Low Insulation Problem Of Insulated Contact Box Busbar And Its Preventive Measures

Insulation Contact Box is the core component of the switch cabinet. If it fails, it will cause all units to stop operating, causing huge economic losses to the wind farm. Most of the indoor switchgear structures of wind farms can be divided into two parts according to their composition: cabinet and trolley. The cabinet is mostly made of aluminum-zinc plate double-bent by CNC machine tools and assembled with high-strength bolts. The switch cabinet adopts composite insulation, the main circuit adopts insulated busbar, and the phases and connectors are equipped with insulating sleeves made of flame-retardant material injection molding. The main busbar is a segmented busbar, and the adjacent switch cabinets are separated by wall bushings with shielded wires, which can effectively prevent the spread of accidents and also play an auxiliary support role for the main busbar. A metal valve is installed in front of the high-voltage busbar contact box. The upper and lower valves are automatically opened when the trolley moves from the test position to the working position, and automatically closed when the trolley moves in the opposite direction, forming an effective isolation. The following will analyze the problem of low insulation of the busbar of a 35kV switch cabinet in a certain wind farm and briefly analyze the preventive measures.