electrical antriebsverfahren and graph with continuous change in velocity and rigid mechanical characteristics

摘要

1,197,648. Control of synchronous motors. MINISTRY OF MACHINE BUILDING INDUSTRY. 12 Feb., 1968 [13 Feb., 1967], No. 6832/68. Heading H2J. [Also in Divisions G2-G3] The armature 3 of a synchronous motor B is supplied with constant amplitude pulses of variable mark/space ratio from a frequency converter A comprising an A.C./D.C. converter 1 and a thyristor inverter 2 controlled by converters 5, 6 which respectively determine the frequency and width of the output pulses from the inverter. The converter 5 is in turn controlled by the output of a comparator 7 fed with signals representative of the actual pulse frequency and a reference frequency corresponding to the desired motor speed. The converter 6 is controlled by a comparator 8 fed with signals representative of the measured load angle of the motor and a reference load angle, such that random variations of load torque are damped out. Periodic variations in load torque are compensated by a cyclic programmer or function generator 11 which produces a signal whose period is determined by the actual motor speed and whose shape, amplitude and phase are predetermined in accordance with the operating conditions of the motor to provide optimum control. The output from programmer 11 is fed to a circuit 10 which combines this signal with three other signals respectively representative of:- (1) A reference excitation current for the field winding 4 of the motor. (2) The output of a transducer 12 fed from a comparator 13 providing an error signal in accordance with the variation from a set value of the A.C. voltage supplying the converter 1. (3) The output of a transducer 14 fed from a comparator 15 providing an error signal in accordance with the variation from a set value of the temperature of the motor winding. The output of combining circuit 10 controls an amplifier 9 supplying excitation current to the field winding 4. The converters 5, 6 respectively control the firing and extinguishing of the thyristors in the inverter 2.