FIG. 9 is a circuit diagram of a fourth embodiment according to the present invention for use with the implementing example shown in FIG. 8A or 8B. In the permanent-magnet synchronous motor driving and resistance control system 100c of the instant embodiment, a circuit diagram is similar to the circuit diagram of the embodiment shown in FIG. 4. As shown in the drawing, in addition to the stator windings 311 being connected through the first rectifier and filter circuit 641 of the resistance controller 64 to the charging circuit 71, the electricity generation winding 312 is also connected through a second rectifier and filter circuit 313 to the charging circuit 71.

Thus, when the permanent-magnet synchronous motor 3 is operating in the first operation mode (namely, the generator mode), the electricity generation winding 312 simultaneously generates a backward charging voltage that is fed through the second rectifier and filter circuit 313 to the charging circuit 71, and the charging circuit 71 then generates backward charging electrical energy supplied to the energy storage device 72. Meanwhile, the generation voltage generated by the stator windings 311 of the permanent-magnet synchronous motor 3 is fed through the first rectifier and filter circuit 641 to also supply to the charging circuit 71 to generate backward charging electrical energy for supplying to the energy storage device 72.