Fully Insulated Tubular Bus Bar

WOPENG Fully Insulated Tubular Bus Bar serves as the core solution for the new generation of power transmission systems. It adopts a fully shielded, fully insulated, and fully protected design to eliminate risks of electric shock and external interference. The product covers a full voltage range from 0.4kV to 550kV, with a wide temperature adaptation capability from -45℃ to 250℃, seismic resistance up to an intensity of 8 degrees, and pollution resistance meeting the stringent requirements of Class V environments. Through a multi-layer insulation structure and capacitive voltage equalization technology, it achieves uniform electric field distribution, with partial discharge levels below 5pC and a design lifespan exceeding 30 years.

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Aluminum Alloy Tubular Bus Bar

The 6063G aluminum-magnesium alloy tube busbar is a key equipment material for power transmission and transformation systems, primarily manufactured by Jiangsu Wopeng Electric Power Equipment Co., Ltd. It includes 6063G aluminum-magnesium alloy tube busbars, LF-21Y aluminum-manganese alloy tube busbars, 6R05 rare earth aluminum alloy tube busbars, and 2A14 heat-resistant aluminum alloy tube busbars. These are mainly used as overcurrent conductors in 220KV, 500KV, 750KV, ±800KV, and 1000KV substations and converter station projects of power companies worldwide, as well as in high-current DC de-icing devices. Its main performance characteristics are: It adopts advanced hot-top casting seamless tube technology, resulting in a smooth surface, high dimensional accuracy, high tensile strength, and resistance to discharge and deformation; it uses rare earth and heat-resistant aluminum alloy materials independently developed by the company and for which national invention patents have been applied, possessing excellent processing, welding, electrical conductivity, and heat resistance properties, and has been certified by scientific and technological departments as reaching international advanced levels; it has good convection heat dissipation conditions, low temperature rise, low loss, strong conductivity, and large current carrying capacity; it has excellent heat resistance, with an operating temperature of 150°C–200°C, and maintains high mechanical strength even at high temperatures, significantly improving the safety and reliability of power transmission and transformation systems; its installation footprint is only about 1/3 that of flexible conductors, and it features corrosion resistance, resistance to icing, strong disaster resistance, and long service life; it is easy to install, aesthetically pleasing, safe, stable, and reliable in operation, and convenient for inspection and maintenance.

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Medium And Low Voltage Bus Bar

Medium and low voltage bus bars primarily include the full series of insulated tubular bus bars rated at 0.4 kV, 10 kV, and 35 kV. Among them, the 0.4 kV low‑voltage series covers rated currents from 1000 A to 8000 A, employs copper tubular conductors and epoxy casting technology, and maintains a temperature rise below 30 K. The 10 kV medium‑voltage series and 35 kV high‑voltage series both cover a current range of 1000 A–8000 A, utilizing epoxy casting and wrapped insulation processes respectively, with temperature‑rise limits of <30 K and <45 K respectively. All medium and low voltage bus bars comply with DL/T 1658‑2016 and DL/T 5789‑2019 standards. They feature a fully insulated enclosed structure, capacitive screen voltage‑grading technology, and high‑purity T2 copper conductors. These products offer comprehensive advantages such as high current‑carrying capacity, low skin effect, high mechanical strength, long span capability, vibration resistance, full insulation shielding, high protection rating, and adaptability to harsh environments. They are widely used in scenarios including substations, wind‑solar booster stations, industrial power distribution, and data centers.

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Products Industry knowledge

1. What Is a Tubular Bus Bar?

A tubular bus bar is a hollow, cylindrical conductor made from aluminum or copper alloys, designed to carry high electrical currents within switchgear, substations, and power distribution systems. Unlike solid rectangular or flat bus bars, the tubular shape offers superior mechanical strength, lower skin effect losses, and enhanced natural cooling. Typical outer diameters range from 40 mm to 200 mm, with wall thickness between 3 mm and 10 mm, accommodating current ratings from 800 A up to 6000 A.

Due to its efficient geometry, a tubular bus bar reduces electric field stress and improves voltage distribution uniformity, making it highly suitable for medium and high-voltage installations. It is commonly fabricated from high-conductivity aluminum alloys such as 6063-T6 or copper with plated contact surfaces, ensuring both electrical performance and long-term reliability in demanding environments.

In modern power systems, tubular bus bars are widely applied in air-insulated substations (AIS), gas-insulated switchgear (GIS), and renewable energy facilities, where compact design and stable current transmission are critical requirements.

2. How Does a Tubular Bus Bar Work?

A tubular bus bar provides a low-impedance path for current flow, combining conductivity, reduced skin effect, and efficient heat dissipation. Compared to solid conductors, AC resistance can be reduced by 15–25%, improving energy efficiency and lowering transmission losses in long-distance or high-current applications.

Its performance is governed by electrical conductivity, conductor geometry, and thermal characteristics. By optimizing these factors, tubular bus bars ensure stable current flow while maintaining acceptable temperature rise under continuous operation.

(1) Skin Effect Reduction

The hollow structure increases effective surface area, allowing more uniform current distribution. A 100 mm aluminum tube can carry about 25% more current than an equivalent solid conductor. This advantage becomes more significant at higher frequencies and larger conductor sizes.

(2) Mechanical & Thermal Performance

Its cylindrical form provides strong resistance to electromagnetic forces during short-circuit events and enhances cooling performance through natural convection. The inner and outer surfaces of the tube allow better heat exchange, helping maintain safe operating temperatures even under high load conditions.

Comparison of tubular vs. solid bus bar (4000A, 60Hz)
Parameter	Tubular Bus Bar	Solid Bus Bar
Weight	~6.2 kg	~18.5 kg
AC Resistance Ratio	1.08	1.32
Cooling Area	High	Moderate
Short-circuit Strength	95 kA	70 kA

3. Key Advantages & Applications

Tubular bus bars are widely used due to their efficiency and reliability in modern power systems:

Higher ampacity with reduced weight, improving structural efficiency
Lower corona discharge effect, especially important in high-voltage systems
Strong resistance to vibration and mechanical stress
Simplified installation and flexible maintenance

These advantages make tubular bus bars ideal for substations, wind power systems, photovoltaic plants, industrial manufacturing facilities, and transformer connections. Their ability to handle high current loads while maintaining compact dimensions supports the development of modern energy infrastructure and smart grid systems.

4. Frequently Asked Questions (FAQs)

Q1: Current rating?

Typically ranges from 1600A to 5000A depending on diameter, material, and cooling conditions. Larger diameters and optimized designs can support even higher currents.

Q2: Aluminum vs copper?

Aluminum is lighter and more cost-effective, making it suitable for large-scale installations, while copper offers higher conductivity and is preferred for compact systems requiring maximum efficiency.

Q3: Installation method?

Most systems use bolted or clamp-type connections, allowing quick installation, easy expansion, and convenient maintenance without complex welding processes.

Q4: Outdoor use?

Yes, tubular bus bars are suitable for outdoor use when treated with anodizing or protective coatings to resist corrosion, UV exposure, and environmental pollution.

Q5: Temperature limit?

Typically 90°C for aluminum under normal operating conditions, with higher limits possible for short-duration emergency loading depending on insulation and design standards.

Tubular bus bars continue to evolve, offering high efficiency, structural reliability, and compact design for modern power transmission and distribution systems.