The Importance of High-Voltage Wire Materials in Electric Vehicles

1. Introduction

Electric vehicles (EVs) are transforming the way we travel, offering a cleaner and more efficient alternative to traditional gas-powered cars. But behind the smooth acceleration and quiet operation of an EV lies a crucial component that often goes unnoticed—high-voltage wires. These wires are responsible for transmitting power between the battery, motor, and various electrical components, acting as the lifeline of the vehicle’s power system.

As EVs become more advanced, the demands on high-voltage wiring systems are increasing. Safety, efficiency, and durability are key concerns, making material selection a critical factor. So, what materials are best suited for high-voltage EV wiring? Let’s break it down.

2. Types of High-Voltage Wire Insulation Materials

To ensure safe and efficient operation, high-voltage wires must be insulated with high-quality materials that can withstand heat, electrical stress, and environmental challenges. Here are the most common insulation materials used in EV high-voltage wires:

2.1. Polyvinyl Chloride (PVC)

PVC was once widely used due to its low cost and good mechanical properties. It’s easy to process and offers decent durability. However, PVC has some significant drawbacks:

• It contains chlorine, which makes it harmful to the environment and human health.
• It has poor heat resistance, which can lead to degradation under high temperatures.
• It tends to harden and crack over time, especially in extreme conditions.

Because of these issues, many manufacturers are moving away from PVC in favor of more advanced materials.

2.2. Cross-Linked Polyolefin (XLPO)

XLPO is one of the top choices for high-voltage EV wires. Here’s why:

• Superior heat resistance: It can withstand high temperatures without degrading.
• Excellent mechanical strength: Resistant to bending, stretching, and impact.
• Durability: Longer lifespan due to its resistance to aging and wear.
• Chemical stability: Resistant to corrosion and harsh environments.

One drawback is its relatively weak flame resistance, but halogen-free flame-retardant XLPO is commonly used to address this issue. Because of its strong performance, XLPO is now a primary choice for EV high-voltage wires.

2.3. Thermoplastic Elastomer (TPE)

TPE is a flexible and easy-to-process material that combines the properties of rubber and plastic. It offers:

• Good elasticity at normal temperatures.
• Moldability, making it easy to shape into different wire structures.

However, it has some weaknesses:

• Lower wear resistance compared to XLPO.
• Inferior high-temperature performance, making it less suitable for demanding EV environments.

Because of these limitations, TPE is not the best option for high-voltage wiring but is still used in certain applications.

3. Standards for EV High-Voltage Wires

To ensure safety and reliability, high-voltage wires in EVs must meet strict industry standards. Here are some of the key standards used worldwide:

International Standards:

• IEC Standards: Cover electrical, mechanical, and thermal properties.
• ISO Standards:
  • ISO 19642: Focuses on road vehicle cables.
  • ISO 6722: Covers low-voltage cables but is sometimes referenced in EV applications.

Chinese National Standards:

• QC/T 1037: Regulates high-voltage cables for new energy vehicles.
• CQC 1122: Focuses on EV charging cables.

Other Certifications:

• LV216: German automotive cable standard.
• DEKRA K179: Tests flame resistance and fire safety.

4. Key Performance Requirements

High-voltage cables must meet several demanding requirements to ensure safe and reliable operation in EVs. Let’s look at the key performance factors:

4.1. Electrical Performance

• Handles high voltage and large current: EV high-voltage systems typically operate at 400V to 800V, requiring cables with excellent insulation.
• Prevents electrical leakage: Poor insulation can cause power loss or even dangerous short circuits.
• Withstands high voltage stress: As EV battery voltage increases, cables must resist electrical breakdown.

4.2. Physical Performance

• Heat Resistance: During fast charging or high-speed driving, cables must withstand high temperatures without melting or degrading.
• Cold Resistance: In freezing conditions, the insulation must stay flexible and not become brittle.
• Flexibility: Cables must bend and route easily during installation and operation.
• Mechanical Strength: Wires must endure vibration, impact, and stretching without breaking or losing performance.

4.3. Chemical Performance

• Oil and Fluid Resistance: Must withstand exposure to lubricants, battery electrolytes, and other automotive fluids.
• Corrosion Resistance: Protects against damage from chemicals and harsh environmental conditions.

5. Future Trends and Innovations

The development of next-generation high-voltage wire materials is an ongoing process. Here’s what the future holds:

• Higher current-carrying capacity: As battery voltages rise, cables must support even higher power levels.
• Better heat resistance: New materials will handle extreme temperatures even better than today’s XLPO.
• Sustainability: The industry is shifting toward environmentally friendly materials that reduce pollution and improve recyclability.
• Improved fire safety: New insulation formulations will offer better flame resistance without toxic chemicals.
• Advanced manufacturing: Innovations in extrusion and processing techniques will enhance cable performance while lowering production costs.

Conclusion

High-voltage cables are an essential but often overlooked part of an electric vehicle. Choosing the right insulation material ensures safety, efficiency, and durability, contributing to the overall reliability of EVs. As technology advances, we can expect even better materials that enhance performance while being more sustainable. The future of EV wiring is bright, and continuous innovation will help drive the industry forward!

Winpower electric vehicle high-voltage wire materials cover multiple temperature levels from 105℃ to 150℃. In practical applications, they demonstrate excellent heat resistance, electrical insulation, high environmental protection and mechanical properties, providing reliable guarantees for the stable operation of vehicles. At the same time, with excellent performance advantages, they effectively solve the performance shortcomings of traditional materials in complex environments, providing strong support for the safe operation of electric vehicles under special working conditions.