| 摘要 |
PROBLEM TO BE SOLVED: To produce a thrust proportional to a thrust command by superposing a signal for compensating the variation in the thrust of a linear motor on the thrust command signal of linear motor and controlling the thrust of linear motor using the superposed signal thereby compensating for the effect of lowered thrust or reverse thrust. SOLUTION: The difference between a speed command signal 12 and the signal from a speed detector 11 is inputted to a speed controller 13. In response to the differential signal, the speed controller 13 produces an output signal for commanding the thrust of a linear motor. On the other hand, a signal corresponding to thrust reduction/reverse thrust of motor is operated by a compensator 14 which delivers an output signal to an adder 15. The adder 15 adds the outputs from speed controller 13 and compensator 14 and delivers an output signal to a current controller 16. An inverter 2 executes PWM control for controlling the output voltage and frequency thus controlling the current flowing through the linear motor. |
