Busbar bridge connections are typically achieved using bolted, clamped, or riveted joints, each offering distinct mechanical and electrical performance characteristics.

Overview of Busbar Bridge Connections

Busbar bridges are used to connect two or more busbars to form a continuous electrical path or to create tap-off points in power distribution systems. The connection must ensure low electrical resistance, mechanical strength, and long-term reliability under thermal and environmental stresses .

Common Connection Methods

1. Bolted Joints Bolted connections involve overlapping busbars and securing them with bolts and flat washers to distribute pressure evenly. This method is reliable when properly torqued and allows field assembly. However, drilled or punched holes can slightly distort the current path, and contact pressure may not be perfectly uniform. Using larger washers can mitigate these issues . 2. Clamped Joints Clamped joints also use overlapping busbars but rely on external clamps instead of bolts. This provides nearly uniform contact pressure and avoids obstacles in the current path. Clamps help moderate temperature changes during current fluctuations. While clamped joints require more space, they simplify fabrication by eliminating the need for holes . 3. Riveted Joints Riveted connections are similar to bolted joints but use rivets instead of bolts. They are permanent and cannot loosen, but controlling contact pressure is more challenging, and installation is more labor-intensive .

Design Considerations

• Electrical Performance: Minimize resistance and stray inductance to reduce losses and voltage drops, especially in high-frequency applications like SiC converters .
• Mechanical Strength: Ensure the joint withstands thermal expansion, vibration, and short-circuit forces. Laminated busbars can enhance mechanical stability .
• Thermal Management: Proper contact pressure and material selection (typically copper or aluminum) help dissipate heat efficiently .
• Standards Compliance: Medium-voltage switchgear busbars must meet IEC and ANSI/IEEE standards for thermal, mechanical, and electrical performance .

Practical Tips

• Ensure clean, flat contact surfaces to reduce resistance.
• Use torque-controlled tools for bolted joints to maintain consistent pressure.
• Consider space constraints when choosing between bolted, clamped, or riveted methods.
• For high-frequency or high-power applications, laminated or PCB busbars can reduce loop inductance and improve performance . By selecting the appropriate connection method and adhering to design standards, busbar bridges can achieve reliable, low-resistance, and mechanically robust connections suitable for both medium-voltage switchgear and high-power electronic converters.