In modern power systems, with the continuous increase of electricity load and the increasing demand for power supply reliability and safety, traditional cables and exposed busbars are no longer able to meet the needs of high current, high-density, and compact distribution scenarios. Fully Insulated Copper Tube Busbar, as a new type of high current conductor system, is widely used in key power facilities such as power plants, substations, rail transit, data centers, and large industrial and mining enterprises due to its excellent current carrying capacity, insulation performance, good heat dissipation characteristics, and compact structural design. It has become the transmission backbone of medium and high voltage distribution systems.

1、 Structure composition and working principle

The fully insulated copper tube busbar is made of high-purity oxygen free copper tube as the conductor body, and the outer layer is sequentially coated with multiple layers of high-performance insulation materials. Shielding layers and sheaths can be added according to the usage environment, forming a fully enclosed structure of "copper conductor inner shielding main insulation outer shielding sheath".

-Conductor: Seamless copper tubes with T2 grade or higher purity are used, which have the advantages of low electrical resistivity, high mechanical strength, and strong corrosion resistance. Compared to solid busbars, tubular structures have a larger surface area, which is conducive to the skin effect distribution of current, improves high-frequency current carrying capacity, and reduces self weight.

-Insulation layer: High quality insulation materials such as cross-linked polyethylene (XLPE) or ethylene propylene diene monomer (EPDM) are usually used, which are tightly wrapped around the surface of copper pipes through extrusion or winding processes. The insulation strength can reach 10kV/mm or more, ensuring electrical safety during long-term operation.

-Shielding layer: A semiconductor shielding layer is installed inside and outside the insulation layer to effectively and uniformly distribute the electric field, prevent partial discharge, and extend the insulation life.

-Outer sheath: optional flame-retardant, weather resistant, and UV resistant sheath materials can be used to enhance the protection level of the busbar in harsh environments (up to IP68).

The system is fixed in the distribution room or cable trench by supporting insulators or dedicated brackets, achieving three-phase independent or common box layout, and forming a complete transmission circuit.

2、 Technical advantages and performance characteristics

1. High current carrying capacity and low loss

Copper tube busbar conductors have a large cross-sectional area and a wide heat dissipation area, and the insulation material has good thermal conductivity, allowing for long-term operation at temperatures as high as 90 ℃ to 105 ℃, significantly improving current carrying capacity. Compared to cables of the same cross-section, its current carrying capacity can be increased by more than 30%.

2. Fully insulated design, safe and reliable

The fully enclosed insulation structure avoids short circuit accidents caused by personnel accidental contact, foreign object overlap, and small animal intrusion, greatly improving the intrinsic safety level of the distribution system. Especially suitable for places with limited space, dense population, or complex environments.

3. Excellent dynamic and thermal stability

Copper tube busbars have high mechanical strength and are not easily deformed under short-circuit current impact. It has a large thermal capacity and strong short-term overload capacity, meeting the strict requirements of IEC, GB and other standards for dynamic thermal stability.

4. Easy installation and simple maintenance

Modular design, on-site use of plug-in or bolted connections, fast installation speed, short construction period. The fully insulated structure eliminates the need for traditional bus duct cleaning and insulation testing frequency, resulting in low maintenance costs in the later stage.

5. Good electromagnetic compatibility

The shielding layer effectively suppresses electromagnetic radiation, reduces interference with surrounding weak current systems, and is suitable for data centers, hospitals, laboratories, and other places with high requirements for electromagnetic environment.

3、 Typical application scenarios

-Power plants and substations: used for generator outlets, main transformer connections, and main circuit connections between distribution equipment, replacing traditional rectangular busbars or enclosed bus ducts.

-Rail transit: As a high current feeder line in subway and high-speed railway traction substations, it ensures the continuity and safety of traction power supply.

-Data center: Provide high reliability and low loss power transmission paths for key equipment such as UPS and distribution cabinets.

-Metallurgical, chemical, and large-scale manufacturing enterprises: used as the distribution backbone for high load workshops to meet the needs of high current and continuous operation.

4、 Selection and installation precautions

When selecting, it is necessary to comprehensively consider factors such as system voltage level (commonly 10kV, 35kV), rated current, short-circuit capacity, ambient temperature, installation method (horizontal/vertical, indoor/outdoor), etc. During the installation process, it should be ensured that the support spacing is reasonable to avoid mechanical stress concentration; The connection part should have good contact to prevent local overheating; The grounding shielding layer must be reliably grounded to ensure safety.

The fully insulated copper tube busbar is an important achievement in the development of power transmission technology. It combines high conductivity, high insulation, and high mechanical strength, representing the direction of high-efficiency, safe, and intelligent development of high current distribution systems. With the continuous promotion of China's new power system construction and urban infrastructure upgrading, fully insulated copper tube busbars play an increasingly important role in ensuring power supply safety and improving energy utilization efficiency, becoming the "main artery" in modern power networks.