In the power transmission and distribution system, fleksibel samleskinne and rigid busbar are two core technology solutions, serving the needs of dynamic and static scenarios, respectively. This article from the structural design, material properties, electrical performance, installation, and maintenance of eight dimensions of the comparison, combined with industry cases and authoritative data, reveals the core differences between the two to provide a scientific basis for engineering selection.

Comparison of structural design and material

1. Flexible busbar: multi-layer composite and dynamic adaptability

The flexible busbar adopts the sandwich structure of copper wire row conductor + winding and wrapping layer + interlocking metal armor layer), the conductor is braided by multiple strands of fine copper wires, and the outer layer is wrapped with PET or PI insulating film. Its ductility is more than 100% and can be bent with a radius as low as 6 times the diameter, adapting to complex spaces such as tunnels and roofs.

2. Rigid busbar: monolithic casting and static stability

Rigid busbar is made of solid copper/aluminum rows + glass fiber-reinforced polyester as the core (e.g., Rogers DM1 material), using an extrusion molding process. The typical cross-section is rectangular or channel type, with mechanical strength of 300 MPa or more, suitable for large-span suspension installation.

Electrical Performance and Safety Indicators

a. Load capacity and temperature rise control

Flexible busbar, through layered heat dissipation design, the temperature rise under 3200A current is ≤ 40K (test data of Yanghua Techtronics), while rigid busbar, due to the solid structure, is prone to eddy currents, and the same specifications of the load capacity is reduced by 15%-20%.

b. Protection level and durability

Flexible busbar adopts IP68 fully sealed structure, which can work continuously underwater for 1 meter; rigid busbar is commonly IP55, which needs extra moisture-proof treatment. In terms of life expectancy, flexible busbars are designed for 25 years (automotive field) to 50 years (industrial field), while rigid busbars can last up to 60 years but with 30% higher maintenance costs.

Environmental Adaptability

1. Seismic and dynamic loads

The metal armor layer of flexible busbar can absorb 80% of the vibration energy (LS cable test), successfully used in Shanghai Metro vibration damping system; rigid busbar is prone to bolt loosening when the vibration exceeds 0.5g.

2. Extreme temperature response

• High temperature scenario: flexible busbar PI insulation withstands 200℃ (Rogers data), the rigid busbar glass fiber reinforced polyester upper limit is 130℃.
• Low temperature scenarios: flexible busbar retains 90% of its tensile strength at -40°C; rigid busbar is prone to brittle cracking.

Installation and economic analysis

a. Construction Cost Comparison

Flexible busbar supports continuous laying without joints (maximum length 500 meters), and the installation efficiency is improved by 3 times. Take the national climate demonstration project Shenzhen Indus Center as an example; the construction cost of a 3200A flexible busbar is 42% lower than that of the cable solution. The rigid busbar needs to be lifted in sections, and the cost of each additional elbow rises by ￥2000/place.

b. Total Life Cycle Cost

Industry Application Scenario Breakdown

1. Flexible Breakthroughs in the New Energy Revolution

• Supercharging station: Huawei’s 800kW liquid-cooled supercharging host adopts flexible busbar power supply, realizing a network density of “1km, 1 station.”
• PV Array: Flexible busbar bending feature reduces bracket usage by 23%, helping LONGI reduce cost by $0.7 million/100MW for Qinghai power plant.

2. Rigid demand from traditional industries

• Metallurgical furnace: Baosteel Zhanjiang base adopts a 4000A rigid busbar to withstand 140℃ high-temperature flue gas.
• Data center: Ali Zhangbei data center uses a rigid busbar to achieve 99.999% power supply reliability.

Future trends and technological innovation

Intelligent upgrading: Flexible busbar integrates temperature/current sensors (e.g. Yanghua Techtronics i-Bus system), realizing a fault warning response time of <50 ms. Environmentally friendly materials: BASF develops biobased PI film, which reduces the carbon footprint of flexible busbar by 57%.

Konklusion

The choice between a fleksibel samleskinne and a rigid busbar is essentially a trade-off between dynamic adaptability and static reliability. In the new energy, intelligent buildings, and other emerging areas, flexible busbar has a 25% annual growth rate (MarketsandMarkets 2024 forecast) to reshape the industry pattern, and in heavy industry and infrastructure facilities, rigid busbar is still an irreplaceable “power skeleton.” Engineers need to consider the cost, environment, operation, and other dimensions to develop the optimal power distribution program.