2025-07-07
With the rapid popularization of electric vehicles and charging facilities, circuit safety has become the focus of the industry. As the most basic but critical protection element in the electrical system, EV Automotive and EVSE Fuse builds a safety line for vehicles and charging equipment through the self-fusing mechanism during overload and short circuit. Its performance directly affects the reliability of the system and even affects the life safety of drivers and passengers. The following analyzes the important role of fuses from three core functions.
When the high-voltage system (400V-800V) of electric vehicles and high-power charging piles (up to 600kW) are running, if the circuit load continues to exceed the rated current, the wires and electronic components will accelerate aging due to overheating and even cause fires. The fuse uses a built-in low-melting-point alloy material (such as lead-tin alloy) to quickly heat up and melt when the current exceeds 1.3-2 times the rated value, actively cutting off the circuit. For example, the fuse on the AC input side of the charging pile can monitor abnormal fluctuations in the power grid in real time to prevent the internal module from burning out due to a sudden rise in voltage; while in the battery management system (BMS) of electric vehicles, the fuse protects the high-voltage wiring harness and controller to prevent system failures caused by current overload.
Short circuit is one of the most urgent risks faced by electric vehicles and charging equipment. Damage to the battery pack, charging interface or wiring harness may cause direct conduction between the positive and negative poles, instantly generating hundreds or even thousands of amperes of current. At this time, the fast-fusing characteristics of the fuse become the only protection method that can respond in milliseconds. For example, the high-breaking capacity fuse equipped at the DC output end of the fast charging pile can cut off a current of up to 10kA within 5 milliseconds when a short circuit occurs, avoiding equipment explosion or fire; in the electric vehicle power system, high-voltage DC fuses (such as bolt-type fuses) guard the key lines between the motor controller and the battery to ensure safe isolation during a short circuit.
Modern electric vehicles and charging piles use a multi-level fuse design to achieve precise current diversion through different specifications of fuse current. For example, the vehicle's OBC (on-board charger), DC-DC converter and other subsystems are equipped with independent fuses. Once a module fails, the corresponding fuse blows, which can not only protect other components from being affected, but also help maintenance personnel quickly lock the fault point. In the modular design of the charging pile, each power module is equipped with a micro fuse. When a unit is abnormal, only the power supply of the module is cut off to ensure that other modules continue to operate, significantly improving the availability of the equipment.
Currently, fuse technology is developing towards high melting speed and low power consumption. Ceramic shell fuses are gradually replacing traditional glass tube fuses with their high temperature resistance and strong arc extinguishing performance; recoverable polymer positive temperature coefficient (PTC) fuses automatically resume conduction after the overload is eliminated and are suitable for electronic devices that are sensitive to power outages. In addition, the smart fuse integrates current sensors and communication modules, which can upload the fuse data to the cloud in real time, helping operation and maintenance personnel to warn of potential risks in advance and promote the intelligentization of electrical safety protection.
As the power of electric vehicles and charging piles continues to increase, the performance optimization and innovative application of EV Automotive and EVSE Fuse, as the last barrier to circuit safety, will become an important direction for the industry's technological iteration, safeguarding the sustainable development of the new energy industry.