The understanding of high-voltage safety protection for new energy vehicles can be summarized as follows:
1. Understanding of High Voltage Electrical Systems: The high-voltage electrical systems of new energy vehicles are mainly divided into DC high voltage and AC high voltage. DC high voltage is mainly distributed between the power battery and various driving components, such as the connection between the power battery and the driving inverter, high-voltage compressor, etc. High voltage communication is mainly distributed between the inverter and the drive motor, as well as between the charging interface and the car charger. The voltage and current levels of high-voltage electrical systems are relatively high, usually between 300V and 600V, and the current can reach several hundred amperes, far exceeding the safe tolerance range of the human body.
2. Safety protection measures: Establish a guardian: It is recommended to establish a dedicated guardian to maintain high-voltage electrical components and ensure the safety of the operation process. The guardian should hold a special operation certificate and a low-voltage electrician operation certificate, and supervise the entire operation process. Personal protection: Operators should wear protective equipment such as insulated gloves, insulated hats, insulated shoes, goggles, etc. that meet the voltage level requirements, and avoid wearing metal jewelry. Operating environment inspection: Confirm the safety of the operating environment, set up isolation areas and mark warning signs to ensure that flammable and unrelated metal items are kept away from the site. Power outage and verification: Before maintenance, the negative wire of the low-voltage battery must be disconnected and wrapped with insulating tape, the maintenance switch must be disconnected, and the key must be properly kept to ensure that the power is completely cut off. When disconnecting the high and low voltage wiring harness of the power battery, it is necessary to wear insulation protective equipment and follow the prescribed steps. First, perform a power test to confirm whether the busbar is charged. If there is residual charge, discharge equipment should be used for discharge.
3. High voltage system design and protection: Electrical insulation: Maintaining good insulation of distribution lines and electrical equipment is a fundamental element in ensuring personal safety and the normal operation of electrical equipment. Safe distance: A certain safe distance should be maintained between the charged body and the human body, as well as between the charged body and other facilities and equipment, to prevent electric shock accidents. High voltage interlock and safety power-off: Electric vehicles are equipped with high-voltage interlock circuits. When the vehicle collides or experiences abnormal situations, the collision sensor will trigger a power-off signal, and the high-voltage power supply of the entire vehicle will be disconnected within milliseconds to ensure personnel safety. Functional safety design: such as torque safety management to prevent unexpected vehicle movements; Charging safety design, avoiding conflicts between fast charging, slow charging, and driving modes.
The high-voltage safety protection of new energy vehicles involves a comprehensive understanding of the high-voltage electrical system, strict protective measures, and the implementation of system design and protection strategies. These measures together constitute the safety guarantee system for the maintenance of high-voltage electrical systems in new energy vehicles.