As the core equipment in the field of electric vehicle charging, the principle of DC charging pile is to efficiently convert the AC power in the power grid into DC power through the inverter, the core component inside the DC charger, and directly supply it to the battery of the electric vehicle, so as to realise rapid charging. This technology not only simplifies the charging process and greatly improves the charging efficiency, but also avoids the loss of power conversion by the inverter on board of the electric vehicle, which is an important driving force for the popularisation of electric vehicles. The advantages of DC charging piles, in addition to its efficient charging capacity, can greatly shorten the charging time to meet the user's rapid replenishment needs, but also has a high degree of intelligence, easy to operate and monitor the user to improve the convenience and safety of charging. In addition, the wide application of DC charging piles also helps to promote the improvement of electric vehicle infrastructure and the popularity of green travelling.