A power supply system includes at least one inverter, at least one cell string, and a transformer, where an input end of the at least one inverter is connected to an output end of the at least one cell string, an output end of the at least one inverter is connected to an input end of the transformer, and an output end of the transformer is configured to output a power supply voltage. The output end of the at least one inverter is connected to an output end of an inverter unit.