Patent ID: 8143824

Claim:
A regenerating braking system comprising: a synchronous motor with field coil excitation comprising a cylindrical stator coil, an inverter electrically connected to the stator coil, a battery electrically connected to the inverter, a rotor coil provided in an internal space of the stator coil, a two-way switch electrically connected to the rotor coil, and a capacitor electrically connected to the two-way switch; and a controller electrically connected to the inverter, the two-way switch, and the capacitor, wherein when the first differential calculus of acceleration of a load on the synchronous motor becomes negative, the controller stores regenerative power regenerated in the rotor coil from the stator coil, in the capacitor through the two-way switch, and wherein the controller supplies the regenerative power stored in the capacitor to the rotor coil through the two-way switch.