Patent ID: 7667342

Claim:
A power supply for a vehicle, in which a plurality of batteries are serially connected, and in which a high voltage obtained from the serially connected batteries is supplied as a DC power source to a vehicle-driving electric motor, comprising: a three-level power line forming a direct-current (DC) power supply line with an intermediate connection position of the serially connected batteries serving as a neutral point, the three-level power line including a neutral line connected to the neutral point, a first potential line connected to one end of a row of the serially connected batteries, and a second potential line connected to an opposite end of the row of the serially connected batteries, such that a DC power plus side is provided between the first potential line and the neutral point and a DC power minus side is provided between the second potential line and the neutral point; and a three-level inverter for converting direct-current power supplied from the DC power source via the three-level power line into three-phase alternating-current power supplied to the electric motor, said alternating-current power having a sine waveform where zero points of the sine waveform correspond to the neutral point of the DC power source, the three-level inverter comprising three switching rows arranged in parallel between the first potential line and the second potential line.