ELECTRIC VEHICLE DRIVE SYSTEM, BACKUP POWER SUPPLY DEVICE AND METHOD THEREFOR

An electric vehicle drive system, a backup power supply device and a backup power supply method for an electric vehicle drive system are provided. The method includes: converting a voltage on a high voltage DC bus of an electric vehicle into a backup input voltage; determining whether a low voltage battery in the electric vehicle drive system has power supply abnormity; and determining the backup input voltage to be an input voltage of a low voltage power supply circuit in the electric vehicle drive system, in a case that the low voltage battery has power supply abnormity.