Common box closed bus is suitable for AC 50~60Hz, voltage 3.6~40.5kV, rated current 1000~6800A medium and high voltage transmission system. It is mainly used in:

1.Electrical connection between generator and transformer;

2.Electrical connection between transformer and high voltage distribution cabinet;

3.electrical connection between the AC main exciter and the rectifier cabinet

4.Electrical connection between excitation switch cabinet and motor rotor slip ring;

5.Electrical connection between main circuits of other high voltage equipment.

The series bus has excellent short-circuit resistance, due to the protection of aluminum or weak magnetic steel shell, it can effectively weaken the structural heating caused by eddy current or circulation, reduce the temperature of the bus shell, reduce the power loss, improve the current carrying capacity, and reduce the short-circuit electric power.

The series bus structure is advanced, installation and maintenance holes can be set in the upper or lower part of the bus, for large current indoor bus on both sides of the housing and the lower part can be equipped with ventilation shutters to strengthen heat dissipation and reduce temperature rise.

When the bus line length reaches 20~30m, the bus expansion joint is set to meet the thermal expansion and cold contraction caused by temperature, and the error caused by foundation settlement can be compensated.

In order to eliminate the impact of vibration on the bus bar during the operation of the equipment, the connection of the bus bar and the equipment are made of copper wire soft connection, and the rubber pad is added between the shell to absorb vibration; For the busbar body, the shock absorber can be installed in the system to achieve elastic support for insulators and conductors, which can better avoid the damage caused by mechanical vibration and seismic waves generated by the equipment to the closed busbar.

The heat dissipation of the busbar mainly depends on thermal radiation. In order to strengthen the heat dissipation effect, light gray paint is sprayed on the outer surface of the busbar to reduce the absorption of visible light; Black paint is sprayed on the inner surface of the bus to enhance the internal heat radiation to the housing, while preventing corona.

In order to avoid the condensation phenomenon caused by the temperature difference between indoor and outdoor in winter, a partition device is set up at the wall to completely isolate the outdoor and indoor bus.

In order to improve the allowable operating temperature rise of the bus bar, prevent the electrolytic corrosion of the joint in the coastal open air and the atmosphere with serious electrochemical corrosion, and reduce the contact resistance, all the connection parts are treated with silver plating, so that the allowable temperature rise is increased to 65k, which is much higher than the actual temperature rise at work.

In order to make the natural vibration frequency of the bus avoid the frequency range of resonance (for a single bus, its resonance frequency range is 35~135Hz), and reduce the electric force acting on the bus, the model, specification and strength level of the insulator are optimized, and the span between the insulators is set reasonably.

In order to monitor the temperature of the removable joints, sealed observation Windows can be set up at the connection between the transformer, generator and distribution cabinet and the busbar, and the temperature can be measured directly through the temperature indicator patch or far-infrared temperature measurement device. The supporting intelligent online monitoring system can monitor the operation of the bus system in real time, which greatly facilitates the detection and maintenance work of the operator. The safe operation level of closed bus is improved.