The bus duct has a high current carrying capacity,so its current density increases,averaging over 2.5 cycles,resulting in a significant reduction in product cost.The structure of the busbar connection and socket of the dense bus duct is more complex,the manufacturing difficulty is increased,and the production process cost is high.Copper with a high aspect ratio used for dense bus ducts.Due to the low inductance of the busbars in dense bus ducts,their voltage loss is relatively small,making them suitable for high current long-distance lines and increasing the voltage level at the end of the line.

　　Dense bus duct is a bus duct that is placed tightly against the channel shell after covering the bare bus with insulation material,which is called a dense bus duct.Its characteristic is the fixed method of dense busbar trunking,which is supported by a strong metal shell and can withstand stability under large electric force impacts.Dense bus ducts have strong mechanical stress,so they can be used to adopt busbars with a large width to thickness ratio and arranged vertically.Due to the application of busbars with a large aspect ratio,their heat generation is small while their heat dissipation capacity is large.Therefore,the current carrying capacity is greatly increased,making it suitable for high current busbars.Due to the use of a busbar with a large aspect ratio,the heat dissipation surface of the busbar itself is increased,and it is directly transmitted to the shell through insulation materials,utilizing a strong convective heat dissipation method to improve its heat dissipation conditions.

　　Air insulated busbar trunking is a type of busbar trunking that supports bare busbars with insulation pads inside the casing and relies on air medium for insulation.The air type busbar and housing structure are simple,especially when there are many plug-in holes,so the price is cheap.The fixing method of the air type busbar is to use insulation pads to support it,and set the corresponding span size and line distance according to the requirements of dynamic stability.So its dynamic stability is not as good as that of dense bus ducts.Due to the presence of air medium between busbars and between busbars and enclosures,the heat dissipation performance of the busbar is greatly reduced,thereby reducing its current carrying capacity.

　　Domestic air type bus ducts are equipped with heat dissipation sleeves for bare copper bars,which is beneficial for strengthening insulation and heat dissipation,but also increases the cost.The shell structure of the air type busbar duct is simple,which is more advantageous for busbars with multiple sockets.The air type busbar trunking adopts busbars with a large width to thickness ratio,which is limited by dynamic stability.Therefore,busbars with a small width to thickness ratio are mostly used,resulting in high heat generation and low heat dissipation.Restricted its carrying capacity.So it is suitable for small current busbars.When used for high currents,its cost-effectiveness will greatly decrease.The connection structure of the air type bus duct busbar is simple,the manufacturing process is easy,and the installation is convenient.The air type bus duct busbar has high inductance and voltage loss,making it suitable for low current and short distance lines.