Lightning protection measures for automobile charging pile
The development of electric vehicles can enable each country to better fulfill the task of energy conservation and emission reduction. Environmental protection travel is one of the development directions of the automobile field, and electric vehicles are one of the development trends of the future automobile. In the global environment of environmental protection, electric vehicles are more and more recognized and loved by consumers. As the power source of electric vehicles, the power battery can only travel a limited distance on a one-time charge, so the charging pile comes into being.
The charging pile is a metal body built outdoors. When there is lightning activity nearby, the thunderclouds will generate electrostatic induction, which makes the charging pile in the charged state be induced and have a high voltage, resulting in the occurrence of lightning strikes. In addition, when the charging pile is located in an open and flat area, it may suffer from direct lightning strikes. Lightning current or high pressure may bring electric shock threat to the charging pile and nearby personnel. Generally, AC charging pile is composed of pile body, power input interface, charging interface, protection circuit, control circuit and safety protection device. If necessary, metering device, card reading device, human-computer interaction device and communication interface can also be added. In order to ensure the normal and safe use of charging pile, relevant lightning prevention measures must be taken.
Good grounding can not only ensure the safety of electric shock prevention during charging operation, but also ensure that the channel of lightning into the ground is smooth when lightning strikes, so as to prevent personnel from being struck by lightning. Among them, grounding by the PGND cable in the cable that provides AC power to the charging pile is effective for the personal safety caused by electric leakage, but it has little effect on the lightning protection safety, because the cross-sectional area of the PGND cable is relatively small, and the length of the cable may be relatively long, and they are concentrated in the charging stations beside the highway and in the site. Each charging pile shall be reliably grounded with the grounding system in the station.
At present, a large number of charging piles are being arranged in China and lightning protection of charging piles is urgent. In practical applications, most of the charging piles are in the outdoor or car charging stations, and the outdoor power supply line is vulnerable to the impact of inductive lightning. Once the charging pile is struck by lightning, the charging pile cannot be used without saying, if the car is charging, the consequences may be more serious, and later maintenance is troublesome. Therefore, lightning protection of charging pile is very necessary.
Lightning protection measures for the power system:
(1) AC charging pile, the output end of AC distribution cabinet and both sides of the charging pile are configured with Imax≧40kA (8/20μs) AC power three-stage lightning protection device. Such as THOR TSC4-C40.
(2) DC charging pile, the output end of DC distribution cabinet and DC charging pile on both sides of the configuration of Imax≧40kA (8/20μs) DC power three-stage lightning protection device. Such as THOR TRS3-C40.
(3) In the input end of AC/DC distribution cabinet, configure Imax≧60kA (8/20μs) AC power supply secondary lightning protection device. Such as THOR TRS4-B60.