The transportation is so convenient thanks to the existence of such vehicles as cars. The rise in oil prices has stopped many people from buying cars. However, people will not have such concerns about electric vehicles. Although refueling is saved, the leakage current of charging piles cannot be ignored. The following is about Electric vehicle charging pile Cause of leakage current.

1. Leakage current of semiconductor components

A very small current flows when the PN junction is cut off. D-S forward bias, G-S reverse bias. After the conductive channel is opened, there will be current flow from D to S. But in fact, due to the existence of free electrons, free electrons attach to SIO2 and N+, resulting in D-S leakage current.

2. Power leakage current

In order to reduce interference in switching power supply, EMI filter circuit must be set according to national standard. Due to the EMI circuit, there is a small current to the ground after the switching power supply is connected to the market power, which is called leakage current. If it is not grounded, the shell of the computer will have 110V voltage to the belt, which will make you feel numb when you touch it with your hand. At the same time, it will also affect the work of the computer.

3. Capacitive leakage current

The capacitive medium cannot be non-conductive; When DC voltage is applied to the capacitor, leakage current will be generated in the capacitor. If the leakage current is too large, the capacitor will be heated and damaged. Except for electrolytic capacitor, the leakage current of other capacitors is very small, so the insulation resistance parameter is used to represent its insulation performance, while the leakage current of electrolytic capacitor is used to represent its insulation performance (proportional to the capacity) because of its large leakage. When the rated DC working voltage is applied to the capacitor, it will be observed that the charging current starts to change greatly and decreases with time. The final current that reaches a relatively stable state when it reaches a certain final value is called leakage current.
i=kcu(ua); Where k is the leakage current constant, and the unit is μ a(v: μ f)

4. Filter leakage current

The power filter leakage current is defined as the current from the filter housing to any end of the AC incoming line under the rated AC voltage. If all ports of the filter are completely insulated from the shell, the leakage current value mainly depends on the leakage current of the common mode capacitor CY, that is, mainly depends on the capacity of CY. Due to the leakage current of the filter, which is related to personal safety, all countries in the world have strict standards for it-
-The leakage current of noise filter is generally required to be less than 1mA.

The above is about the reasons for the leakage current of the charging pile of electric vehicles, which can be divided into four types: semiconductor component leakage current, power supply leakage current, capacitor leakage current and filter leakage current. I hope all of them can understand the reasons and get a better solution.