VEHICLE DRIVE SYSTEM

In a vehicle drive system, in at least either of a case where a first ECU receives a collision detection signal or a case where an interlock line is disconnected, the first ECU controls a relay such that electrical connection between a battery and a motor device is disconnected. The motor device includes an electric motor for traveling, a PCU, a second ECU, and a backup power supply. The PCU includes one or more capacitors. When the interlock line is disconnected, the second ECU is activated by electric power supplied from the backup power supply activated along with the disconnection. Under the condition that the second ECU does not receive, from the first ECU, a discharge command to discharge residual charge or that a determination that a collision occurs is made, the second ECU controls the PCU such that the PCU executes a discharge control.