The bushing of the power transformer is used to arch the internal high-voltage and low-voltage cables of the power transformer out of the oil tank, which not only plays the role of grounding insulated cables, but also plays the role of fixing cables. power transformer bushing is one of current carrying components of transformer. In the process of operation, the load current passes for a long time. When a short circuit occurs outside the transformer, the short circuit current passes. Therefore, the following requirements are proposed for the transformer isolator:

(1) It must have the specified electrical strength and sufficient mechanical strength.

(2) It must have good thermal stability and be able to withstand transient overheating during short circuit.

(3) Small appearance, small quality, good sealing performance, strong versatility and convenient maintenance.

The HV, LV and neutral bushings of power transformers are paper oil capacitor bushings. The high-voltage bushing is of double flange structure. One flange is used to install the bushing on the top of the transformer, the second flange is used to connect the SF6 pipeline bus, and the capacitor test socket is drawn between the two flanges. The upper part is sealed in the SF6 duct. The outlet of the enclosure is connected to the bus bar of the SF6 duct.

The low-voltage bushing of the power transformer is connected to the closed bus bar at the low-voltage side, and the connection between the two is soft connection.

Three single-phase transformers are connected with each other through neutral point isolators to form the neutral point of the transformer bank, and the neutral point is directly grounded through the current transformer in the phase B room.