Power unit for electric vehicle

A power unit for an electric vehicle, the power unit comprising:

• a first power source connected between a first node and a second node;
• a first switch connected between the second node and a third node;
• a second power source connected between the third node and a fourth node;
• a second switch connected between the first node and the third node;
• a DC-DC converter connected to the second node;
• and
• a switching unit switching between a first connected condition, a second connected condition, and a third connected condition,
• wherein the DC-DC converter changes an electric potential of the second node by making the second node connectable to the fourth node or the third node, and
• an output electric power obtained from between the first node and the fourth node is supplied to an electric motor, and
• wherein:
• in the first connected condition, the first node is connected with the third node by opening the first switch and closing the second switch,
• in the second connected condition, the second node is connected with the third node by closing the first switch and opening the second switch,
• in the third connected condition, the third node is disconnected from the first node and the second node by opening the first switch and opening the second switch, and
• the switching unit switches between the first connected condition and the second connected condition via the third connected condition.