License plate recognition of charging pile. Charging piles are similar to tankers in gas stations. Can be fixed on the ground or wall and installed in public buildings (public buildings, shopping malls, public parking lots, etc.). ) and parking lots or charging stations in residential areas, and can charge all kinds of electric vehicles according to different voltage levels. The input end of the charging pile is directly connected to the AC power grid, and the output end is equipped with a charging plug to charge the electric vehicle. Charging piles generally provide two charging methods: conventional charging and fast charging. People can use a specific charging card to swipe their cards on the man-machine interface provided by the charging pile and print the corresponding charging method, charging time and cost data. The charging pile display screen can display data such as charging amount, cost and charging time. Charging pile license plate recognition refers to a device that is fixed on the ground in the parking lot or charging station of public buildings and communities such as office buildings, parking lots, shopping malls, etc., and provides man-machine interactive operation interface in a conductive way to help electric vehicles equipped with on-board chargers to conduct AC charging. It has corresponding measurement and control protection devices. The AC charging pile should have residual current action protection function, overcurrent protection function and emergency stop function at the output side. The AC charging pile should have the ability to judge whether the connection between the charging line and the charging connector is accurate. Only when the AC charging pile is connected to the electric vehicle correctly can the charging process be started: when it is detected that the AC charging pile is connected to the electric vehicle abnormally, the charging process must be stopped immediately. In addition, AC charging piles should also have flame retardant function. In order to set the charging mode conveniently, the AC charging pile should be able to control the input equipment manually: the display screen of the AC charging pile should have information such as current charging mode, charged energy and energy to be charged, charged time and remaining time, timing fee, etc. The charging pile should be equipped with a card-swiping interface, which technically supports common forms of card swiping; Charging piles can be equipped with printers to provide bill printing. According to the need, the AC charging pile can upload its running state parameters, accept remote control commands and provide perfect communication functions.