| 摘要 |
PURPOSE:To make the control possible with a minimum power consumption, by constituting a magnetic field by permanent magnets and an auxiliary field winding, and controlling the field current to be flowed into the auxiliary field winding in the required torque region corresponding to a load so that the loss at the motor becomes minimum. CONSTITUTION:A speed command 1 and the signal from a sensor 18, which senses the speed of a drum 14 driven by a motor 6, are input to a comparator 2, and a torque command value 2a is input to an armature-current-command device 21. The armature-current command 21a is input to an armature-circuit phase shifter 3. The magnetic field of the DC motor is constituted by an auxiliary field winding 13' and permanent magnets 22. In the case a contactor 7 is closed, and when a current Ia is flowed in an armature 6 due to the voltage generated by thyristor bridges 5 and 5' which have received signals 3a and 3b from the phase shifter 3, the motor is driven by the magnetic fluxes from the permanent magnets 22. If the torque command 2a is large, the conduction signal is obtained in a thyristor 12 via a field-current-command device 9 and a field-circuit phase shifter 10, and a specified current is flowed in an auxiliary field winding 13'. |
