Compared with traditional fuel vehicles, electric vehicle (EV) fuses have unique design requirements in terms of high-voltage system protection, environmental adaptability, performance parameters, and safety standards.
High-voltage System Protection Requirements
High-voltage Adaptability: The operating voltage of EVs typically ranges from 400V to 800V, significantly higher than the 12V or 24V systems found in traditional fuel vehicles. Consequently, fuses must possess higher insulation performance and voltage resistance to prevent high-voltage arcs or breakdowns.
Fast Fuse Characteristics: Under high-voltage and high-current conditions, the fuse must blow within an extremely short timeframe (e.g., milliseconds) to limit fault current and protect expensive components such as battery packs and motor controllers.
Environmental Adaptability Requirements
Wide Temperature Range: EV fuses need to function normally under extreme temperatures ranging from -40°C to 125°C to accommodate the thermal management requirements of battery packs under various operating conditions.
High Humidity and Vibration Tolerance: They must be moisture-proof, mildew-proof, and corrosion-resistant, and maintain mechanical stability under long-term vibration to prevent poor contact or fuse failure.
Special Requirements for Performance Parameters
Low Internal Resistance Design: To minimize energy loss, the fuse's internal resistance must be as low as possible, enabling it to pass large currents without overheating.
High Breaking Capacity: It must be capable of safely cutting off fault currents (such as short-circuit currents) to prevent continuous arc burning, which could lead to fires or explosions.
Surge Current Resistance: During EV startup or charging, instantaneous surge currents may occur, and the fuse must withstand such impacts without malfunctioning.
Safety and Certification Standards
Compliance with Automotive Standards: Fuses must pass automotive certifications like AEC-Q200 to ensure long-term reliability in harsh environments.
Fireproof and Explosion-proof Design: During the fusing process, arcs and sparks must be suppressed to prevent battery thermal runaway or fires.
Environmental Protection and Recyclability: Fuses must comply with environmental regulations such as RoHS, reducing the use of hazardous substances and facilitating recycling.
Integration and Miniaturization Trend
Compact Design: To fit within the limited space of EVs, fuses must adopt miniaturized and integrated designs, such as PCB-mounted or modular fuse boxes.
Intelligent Functions: Some high-end fuses integrate current monitoring, fault diagnosis, and other functions, and can communicate with the battery management system (BMS) to achieve active protection.
