Engineered to mitigate dynamic vibration, thermal stress, and high-frequency switching EMI in rail traction inverters and power conversion units.
Multi-layer copper foil diffusion-welded design delivering high flexibility, low thermal expansion resistance, and superior insulation for rail vehicle VVVF drive units.
Electro-plated tin, nickel, or silver finishes ensuring ultra-low contact resistance and anti-corrosion protection in high-vibration locomotive engine compartments.
Bimetallic metallurgical bonding technology offering optimal electrical conductivity while reducing overall carriage weight by up to 40% for rolling stock systems.
Engineered specifically for next-generation SiC and IGBT high-power modules, offering minimal skin effect, superior ampacity, and thermal longevity.
How laminated busbar architectures are driving the transition toward high-efficiency, high-reliability rolling stock power systems worldwide.
Modern rail transit systems—including high-speed electric multiple units (EMUs), urban rapid metro trains, light rail vehicles (LRVs), and heavy-haul diesel-electric locomotives—are undergoing unprecedented technological modernization. The core traction drive system operates as the heart of rolling stock, demanding power converters to manage voltages exceeding 3.3kV and currents surpassing thousands of amperes under stringent weight and volume constraints.
Traditional discrete cabling and conventional unlaminated solid copper bars are no longer capable of satisfying the severe electromagnetic, thermal, and mechanical criteria of contemporary rail engineering. The shift toward wide-bandgap semiconductors, particularly Silicon Carbide (SiC) MOSFETs and ultra-fast High-Voltage Insulated Gate Bipolar Transistors (HV-IGBTs), has drastically shortened switching rise times (di/dt), inducing dangerous transient overvoltage spikes unless parasitic inductance is strictly contained.
Through planar multi-layer conductor stacking interleaved with thin high-dielectric insulation films, opposing magnetic fields cancel out, suppressing voltage overshoot and protecting sensitive power semiconductor modules.
Compliant with IEC 61373 (Category 1, Class B) standards, laminated flexible busbars absorb continuous track vibrations and dynamic bogie displacement without mechanical fatigue or contact fretting.
Eliminates complex harness routing inside dense under-car traction boxes and machine rooms, cutting space requirements by over 35% and improving airflow dissipation.
Bridgold precision-engineered laminated and flexible busbars deliver robust power transmission across the complete railway traction architecture.
In high-speed trains and subways, variable-voltage variable-frequency (VVVF) inverters convert DC catenary voltage (or rectified AC) into three-phase AC power. Laminated DC-link busbars interconnect DC filter capacitor banks with power modules, ensuring balanced current distribution and negligible commutation inductance.
Heavy-duty freight locomotives utilize high-output diesel engine generators. Laminated busbars serve as the high-capacity bridge between the main synchronous alternator and the primary diode/thyristor rectification cabinets, managing extreme thermal cycles and strong mechanical engine vibrations.
Auxiliary static converters provide onboard low-voltage power for braking compressors, air conditioning, signaling, passenger lighting, and battery charging. Flexible laminated busbars guarantee stable, noise-free distribution in tightly sealed underfloor compartments.
During dynamic and regenerative braking cycles, substantial surge currents are channeled to braking resistors. Laminated copper connectors offer superior surge withstand capability and uniform thermal expansion, eliminating hot-spot failures during emergency stops.
Connecting pantograph incoming power lines, vacuum circuit breakers (VCB), and primary potential transformers. Copper-aluminum composite and nickel-plated flexible busbars ensure weather-proof, ozone-resistant, and corrosion-free operation under open-air atmospheric conditions.
Bridging rigid car-body inverter terminals and bogie-mounted permanent magnet synchronous traction motors (PMSM). Highly flexible bare or insulated foil connectors endure multi-axis cyclic twisting, bogie steering displacement, and flying ballast impact.
| Subsystem / Scenario | Primary Technical Requirement | Recommended Busbar Architecture | Key Benefit |
|---|---|---|---|
| IGBT / SiC Inverter Bridges | Parasitic inductance ≤ 12nH, high switching frequency | Multi-layer Planar Copper Laminated Busbar with Nomex/Kapton | Suppresses switching overvoltage; prevents device punch-through |
| Diesel-Electric Engine Alternators | Vibration isolation, high continuous current (2000A+) | Flexible Plating Copper Foil Laminated Connectors | Absorbs continuous engine harmonic vibrations; zero joint fatigue |
| DC-Link Capacitor Banks | Distributed capacitance, uniform current density | Wide Copper-Foil Laminated Plates with Sealed Edges | Eliminates ripple-current overheating; extends capacitor service life |
| Inter-Cabinet Jumper Connections | Dynamic misalignment compensation, lightweighting | Copper-Aluminum Composite & Flexible Insulated Shunts | Reduces carbody weight; facilitates rapid modular maintenance |
Zhejiang Bridgold Copper Tech Co., Ltd. is a national-level high-tech enterprise specializing in the research, development, design, and production of flexible conductive connection products. The company is located in the Yueqing Economic Development Zone, Wenzhou City, Zhejiang Province, occupying 46,000 m² of land with a total construction area of nearly 100,000 m².
Bridgold is dedicated to the intelligent manufacturing of a comprehensive range of flexible conductive products, including:
Our products are widely used in electric vehicles, energy storage systems, charging infrastructure, wind power, industrial control, rail transit, and medical equipment. With a strong focus on quality and innovation, Bridgold has built a solid reputation both domestically and internationally. Our products are sold throughout China and exported to North America, Europe, Southeast Asia, the Middle East, Africa, and beyond.
As a trusted supplier to many Fortune Global 500 companies and industry leaders, Bridgold has established long-term, stable partnerships with renowned enterprises such as:
In 2010, the company entered the qualified supplier list for Siemens Healthcare and GE Wind Energy, marking a significant milestone in its global expansion. To date, our copper braided wire series products rank No.1 in global market share, a testament to our manufacturing excellence and customer trust.
In the new energy vehicle sector, our products have been successfully applied in major automotive brands such as Mercedes-Benz, BAIC, SAIC, JAC, NIO, FAW, and Great Wall Motors, ensuring the safety and performance of automotive electrical connection systems.
As of 2025, Bridgold has accumulated 51 national patents, including 16 invention patents. The company participated in the formulation of the national standard GB/T 37133 “High-voltage connection system for electric vehicles”. Our core technologies cover cutting-edge fields such as superconducting connection materials, high thermal conductivity composites, and intelligent manufacturing processes.
Bridgold has established a professional copper connection technology R&D center with strong research capabilities, recognized by the Zhejiang Provincial Government as a “Zhejiang Provincial Enterprise Technology R&D Center” and “Zhejiang Provincial Enterprise Technology Center”. These certifications ensure comprehensive technical quality control throughout the entire process—from raw material quality analysis and manufacturing process development to product quality inspection.
In response to global industrial upgrading and green transformation, Bridgold continues to advance intelligent manufacturing and digital transformation. We have invested in the development and introduction of high-end manufacturing and testing equipment, building a personalized, digitalized, efficient, and standardized intelligent manufacturing system.
The company actively promotes the standardization of products and technologies by participating in the formulation of industry standards. Through industry-university-research collaboration with universities and research institutions, we jointly tackle common technical challenges in the industry, building distinctive technological advantages.
Meeting the world's most rigorous rolling stock and locomotive propulsion validation criteria.
Using solid-state thermo-compression diffusion welding technology, copper/aluminum foils are fused at the molecular level without brazing flux. This delivers 100% electrical conductivity across joints, zero void entrapment, and superior flexural endurance under cyclic shock loads.
Employing DuPont™ Nomex®, Kapton® polyimide, Tedlar® PVF, and epoxy powder coating systems. Ensures high partial discharge inception voltage (PDIV), zero corona degradation at 3000m+ altitudes, and compliance with EN 45545-2 (HL1 to HL3) flammability, smoke, and toxicity mandates.
Every traction busbar batch undergoes 100% high-potential (Hi-Pot) dielectric testing, partial discharge analysis, thermal cycling validation (-50°C to +150°C), micro-ohm contact resistance inspection, and salt-spray corrosion testing under ISO/TS 22163 (IRIS) standards.
Explore Bridgold's complete series of high-performance conductive connectors, busbars, and custom interconnect assemblies.
Diffusion-welded copper foils with custom high-dielectric flame-retardant insulation for EMU traction inverter connections.
Tin, nickel, and silver-plated contact surfaces providing oxidation protection in harsh railway locomotive operating environments.
Solid-state bonded copper-clad aluminum busbars for energy-efficient, high-ampacity carriage and switchgear distribution.
Interleaved noble-metal foil laminates designed for extreme thermal conductivity and ultra-high frequency switching stability.
High-precision CNC machined rigid aluminum conductors for main power cabinets, auxiliary power units, and substations.
Ultralight multi-layer aluminum foil flexible connections engineered for rail energy storage and battery auxiliary modules.
High-purity T2/Cu-ETP bare laminated copper shunts providing maximum conductivity and optimal heat dissipation performance.
Tailored multi-layer laminated busbar sub-assemblies integrating snubbers, sensors, and structural mounting hardware for locomotives.