On-vehicle power supply system and electric vehicle

An on-vehicle power supply system, comprising:

• a power battery;
• a charge-discharge socket configured to connect with an external load;
• a three-level bidirectional DC-AC module having a first DC terminal connected with a first terminal of the power battery and a second DC terminal connected with a second terminal of the power battery;
• a charge-discharge control module having a first terminal connected with an AC terminal of the three-level bidirectional DC-AC module and a second terminal connected with the charge-discharge socket;
• and
• a control module connected with a third terminal of the charge-discharge control module and a control terminal of the three-level bidirectional DC-AC module, and the control module being configured to control the three-level bidirectional DC-AC module to convert a DC voltage of the power battery into an AC voltage with a predetermined value, and to provide the AC voltage to the external load via the charge-discharge control module and the charge-discharge socket.