As another example of the power module 110, at least one of the cooling unit 120, the drive substrate 160, and the protective member 180 may be deleted from the power module 110. The electric power conversion device 5 may not have the smoothing capacitor C2. The capacitor C1 may be arranged outside the protective member 180. The structure of the cooling unit 120 may not be limited to the example described above. A part of the semiconductor device 20 forming the upper and lower arm circuit 10 may be inserted into the flow path 126 of the cooling unit 120 to be immersed in the refrigerant. In such a configuration, the capacitor C1 may be placed on the cooling unit 120 to be connected to the semiconductor device 20. In the case where the capacitor C1 is immersed in the refrigerant, it is possible to suppress the surge voltage while cooling the semiconductor device 20 from both sides.
(Motor Generator)