| 摘要 |
PURPOSE:To accurately control the speed in a wide range by stepwisely switching the exciting frequency of a resolver for detecting a speed in reponse to the speed. CONSTITUTION:A resolver 12 is excited by a resolver exciter 13, the period T of a detection signal of the resolver 12 is measured by a speed detector 14, the value T corresponding to the rotor speed N of a synchronous motor 11 is detected, a resolver 15 is excited by a resolver exciter 16, the excitation signal of the resolver 15 and the phase difference theta of a detection signal are measured by a rotating angle detector 17 to detect a field pole position theta of the motor 11. Further, a microprocessor 18 outputs a 2-phase current command through D/A converter 19, 20 on the basis of outputs from the resolvers 12, 15 to a current controller 21, and outputs a coded excitation switching signal to a resolver exciter 13 to switch the exciting frequency of the resolver 12. |
