POWER SUPPLY CIRCUIT FOR ENERGY TRANSFER BETWEEN BATTERY AND SMOOTHING CAPACITOR, BATTERY MANAGEMENT SYSTEM AND BATTERY PACK

Provided is a power supply circuit for energy transfer between a battery and a smoothing capacitor, a battery management system and a battery pack. The power supply circuit includes a transformer including a first winding and a second winding, a first switching circuit including a first switch connected in series to the first winding, and connected in parallel to the battery together with the first winding, a second switching circuit including a second switch connected in series to the second winding, and connected in parallel to the smoothing capacitor together with the second winding, and a switch controller. To pre-charge the smoothing capacitor, the switch controller is configured to perform a first operation of turning on the first switch and turning off the second switch, and subsequently perform a second operation of turning off the first switch and turning on the second switch.