Detailed Processing Flow of High-Voltage Harnesses for New Energy Electric Vehicles
As the global new energy vehicle (NEV) industry accelerates, high-voltage harnesses stand as the "power arteries" of electric vehicles, directly impacting overall safety and reliability. Unlike low-voltage harnesses in traditional fuel-powered cars, NEV high-voltage harnesses must withstand 300V–800V voltages and currents exceeding 200A—demanding stricter standards for material selection, production processes, and quality control. Below is a detailed breakdown of their full manufacturing journey, from raw materials to finished products.
Every material in a high-voltage harness is engineered to handle extreme electrical loads and harsh environments:
- Conductors: Multi-stranded copper wires (16mm²–150mm² cross-sectional area) form the backbone. Most undergo tin-plating to enhance oxidation resistance; in specialized applications, silver-plated copper reduces contact resistance for superior efficiency.
- Insulation: Cross-linked polyethylene (XLPE), silicone rubber, or PTFE are chosen for their ability to resist temperatures of 150°C–200°C, preventing short circuits under high current.
- Shielding: A dual-layer structure (aluminum foil + braided copper mesh) ensures >85% coverage, effectively blocking electromagnetic interference (EMI) that could disrupt sensitive vehicle electronics.
- Sheathing: Flame-retardant TPE or TPU materials, certified to UL94 V-0 standards, provide durability. They meet industry abrasion resistance requirements, protecting the harness from wear in tight engine bays or undercarriages.
Before production begins, rigorous design and testing ensure the harness performs flawlessly in real-world conditions:
- 3D Routing Simulation: Using CATIA software, engineers simulate the harness layout within the vehicle to avoid mechanical interference and heat sources (e.g., motors or batteries) that could degrade performance.
- Electrical Performance Calculations: Precise analysis guarantees voltage drop ≤3%, temperature rise ΔT ≤40°C, and sufficient current-carrying capacity—preventing overheating even during fast charging.
- EMC Simulation: CST software predicts electromagnetic radiation levels, optimizing the shielding design to meet strict EMC standards and avoid interference with GPS, ADAS, or other systems.
- Environmental Testing: Prototypes undergo extreme trials: 2,000-hour salt spray tests (for corrosion resistance), 3,000 insertion/extraction cycles (for durability), and temperature shocks from -40°C to 150°C (to mimic diverse climates).
- Automated Cutting: Servo-driven machines cut cables to length with ±1mm precision, ensuring clean, burr-free ends that won’t damage insulation or connectors.
- Laser Marking: UV lasers etch wire IDs, specifications, and other details onto the sheath, creating permanent marks (0.15–0.3mm deep) that withstand harsh conditions—critical for installation and maintenance.
- Terminal Crimping: Fully automated crimping machines achieve ±0.02mm tolerance in crimp height, with cross-sectional analysis meeting VW60330 standards (a global benchmark for crimp quality).
- Shielding Handling: The dual shield is meticulously processed: aluminum foil is wrapped 360° for full coverage, while copper mesh is braided to >90% density, eliminating EMI leakage.
- Injection Molding: Vertical injection machines shape protective housings, with mold temperatures controlled at 80±5°C. Hold pressure is adjusted based on material thickness to ensure uniform, gap-free parts.
- Waterproofing: A dual-seal system (rubber gaskets + potting compound) achieves IP67/IP6K9K ratings, protecting against water immersion and high-pressure washes—vital for undercarriage or outdoor-mounted harnesses.
- High-Voltage Connector Assembly: Pneumatic tools apply 50–80N·m torque to secure connectors, ensuring contact resistance <0.5mΩ to minimize power loss.
- Harness Bundling: Heat-resistant zip ties secure the harness every 150–200mm, with a minimum bend radius 5x the cable diameter—preventing damage to conductors or insulation during vehicle movement.
High-voltage harnesses are more than just wires—they’re the lifelines of EVs. A single flaw can lead to power failures, overheating, or safety risks. By combining premium materials, advanced simulation, and precision manufacturing, this process ensures harnesses meet the demands of NEVs: high voltages, vibration, extreme temperatures, and moisture.
For manufacturers, mastering this process isn’t just about compliance—it’s about building trust. Drivers, automakers, and regulators rely on high-voltage harnesses to deliver safe, reliable performance, making them a cornerstone of the electric mobility revolution.
Ready to elevate your high-voltage harness production? Partner with experts who specialize in these precision processes—your EV’s performance depends on it.
