To smoothly and surely provide braking force until wheels are brought into a stopped state by suppressing the rotation of the wheels only through the control of a motor without requiring a friction braking device.

The device is provided: with an embedded permanent magnet field type synchronous motor IPM including a rotor having a permanent magnet and a stator capable of rotationally driving the rotor to couple the rotor to a wheel W; with a power accumulating portion BT for accumulating power to be supplied to the permanent magnet synchronous motor; with a conversion control means IV for controlling the rotation of the rotor by converting the power and exciting the stator; and with an in-phase excitation control means PEB for applying an exciting brake to the wheel W by exciting the stator by supplying power in the same phase as the excitation with respect to the stator in a rotating direction of the rotor, which corresponds to the control performed by the conversion control means, wherein the wheels are stopped by the exciting brake.