High voltage bus
Structural features: this series of bus Bridges have excellent short-circuit resistance. Due to the protection of aluminum (or weak magnetic steel plate) shell, it can effectively slow down the structural heating caused by weak eddy current or circular flow, reduce the shell temperature of bus groove, reduce the power loss, increase the load flow and reduce the electric power.
This series of bus Bridges is advanced in structure. The installation and maintenance holes can be arbitrarily placed on the upper or lower part of the bus bridge. For large-current indoor bus Bridges, ventilation louvers are provided on both sides of the shell and on the lower or upper part to enhance heat dissipation and reduce temperature rise.
The application of double insulation and multi-point connection ground of the shell greatly reduces the maintenance work and improves the safety performance.
In order to solve the negative impact of vibration on the bus bridge caused by transformer, generator and distribution cabinet during operation, soft connection or copper braid is adopted at the connection between the transformer and the bus bridge, and rubber pads are added between the shell to reduce vibration. For the parent cable bridge body, shock absorber is installed in the system to provide elastic support for porcelain bottle and conductive heat, which can avoid the damage caused by mechanical vibration and seismic waves generated by the shell to the closed bus.
The main heat transfer of the bus bridge is thermal radiation. In order to make good use of thermal radiation, light ash coating is sprayed on the outer surface of the bus bridge to reduce the absorption of visible light. Black paint is applied to the inner surface of the bus groove to enhance the radiation of internal heat on the outer shell and prevent corona.
In order to avoid accidental condensation caused by outdoor and indoor temperature changes in winter, a wall sleeve is installed at the access wall, so that outdoor and indoor bus slots are completely isolated. When installed vertically, the flange is inside and when installed horizontally, the flange is outside.
In order to avoid the frequency range of vibration (its resonance frequency range is 35~135Hz for a single bus) and reduce the electric power acting on the bus, the span between insulators is reasonably determined. Select insulator type, specification and strength grade.
In order to facilitate the user, the current transformer can be installed at the generator outlet and one side of the excitation transformer to facilitate the user to detect the current.
Main technical parameters
? insulation resistance: every unit bus duct insulation resistance value should be greater than or equal to 1000 m Ω (2500 v megohmmeter).
? dielectric strength: the first section of the bus duct before delivery after 1 minute love power frequency withstand voltage test, power frequency withstand voltage and lightning shock pressure numerical, see table.
? busbar bridge as every phase in because of the high strength ceramic material make it able to withstand strong electric stress and thermal stress.
? busbar bridge in long-term through rated current, the conductive parts of the temperature rise shall not exceed the tables listed in the extreme.
Rated voltage (kv)
1min working frequency withstand voltage (kv)
Lightning impulse voltage resistance (kv)
? grounding systems: conform to IEC364-5-54 docking system requirements.
Adding ? protection grade: outdoor: IP40 (cover)
? load performance: in the rated power flow, the rise of temperature of the shell accord with GB763-90 "during the high pressure electric appliance in long-term fever" standard requirements.
? short-circuit performance: the dynamic thermal stability test accord with GB2706-89 the exchange of high dynamic thermal stability test method standard requirements.
? busbar bridge cross section shape size and weight per meter as shown in figure and table 2.