POWER SUPPLY DRIVING SYSTEM

A power driving system for an electric vehicle with a motor includes plural battery boxes, a first DC bus, a second DC bus and a power converter. The first DC bus is electrically connected with the battery boxes for selectively receiving electric energy from the battery boxes. The second DC bus is electrically connected with the battery boxes for selectively receiving electric energy from the battery boxes. The power converter is connected between first DC bus and the second DC bus. After the power driving system is changed from a steady state power mode to a driving voltage switching mode, a driving voltage switching process is performed. By the power converter, a voltage of one of the first DC bus and the second DC bus in a steady state is used to adjust a voltage of the other of the first DC bus and the second DC bus.