POWER SOURCE SWITCHING SYSTEM, POWER SUPPLY CIRCUIT SWITCHING METHOD, AND ELECTRIC VEHICLE

A power source switching system, a power supply circuit switching method and an electric vehicle. The power source switching system includes a first power source unit, a second power source unit, and a system switching control unit, the system switching control unit electrically connected to the first power source unit and the second power source unit, where the system switching control unit controls the first power source unit and the second power source unit to be connected in series or in parallel, and controls switching between the series connection of the first power source unit and the second power source unit and the parallel connection of the first power source unit and the second power source unit, implementing a charging and discharging process of the first power source unit and the second power source unit.