Chargers and chargers (chargers) can be divided into power frequency machines and high-frequency machines according to the designed circuit operating frequency. Power frequency machines are designed based on traditional analog circuit principles. The internal power components of the machine (such as transformers, inductors, capacitors, etc.) are relatively large, and there is generally small noise when operating under high loads. However, this model has strong resistance performance in harsh power grid environmental conditions, and its reliability and stability are stronger than high-frequency machines.