POWER SUPPLY APPARATUS, POWER SUPPLY SYSTEM, AND METHOD

This disclosure discloses a power supply apparatus, a power supply system, and a method. The apparatus includes: a power supply bus connected to an output end of a voltage conversion unit and a low-voltage battery through separate bidirectional isolation units. The bidirectional isolation units control connection and disconnection between the bus and the voltage conversion unit or the low-voltage battery. The bidirectional isolation unit includes two switches connected in series. The two switches connected in series each are connected in parallel to one diode, and the two diodes are disposed back to back. The power supply apparatus further includes another circuit, where the circuit is electrically connected to the bus, and is configured to supply power to a load. Solutions in embodiments are applied to new energy vehicles such as an electric vehicle and a hybrid electric vehicle, to improve functional safety performance of power supply of the vehicles.