| 摘要 |
PURPOSE:To obtain the current control method, of an AC servomotor, wherein, when a d-q conversion is utilized and a voltage instruction is saturated, the shift of a phase is prevented. CONSTITUTION:A d-q conversion is performed (9), and a d-phase instruction voltage Vd is found by a current controller 5d in such a way that a d-phase current Id in the direction of a magnetic flux formed by a field system becomes 0. In addition, a q-phase perpendilcular to a d-axis finds a q-phase voltage instruction Vq while a current loop processing operation is performed (5q) by a q-phase current computed by using a torque instruction as an instruction value. When the composite vector of the voltage instructions Vd, Vq exceeds a clamp value, components of a d-phase and the q-phase in which the phase of the composite vector is the same and whose magnitude corresponds to the vector of the clamp value are used respectively as voltage instructions. During an acceleration operation, a saturation processing operation which rewrites the integrated value of the q-phase to be small is performed. During a deceleration operation, a saturation operation which rewrites both the d-phase and the q-phase to be small is performed. Even when a clamp processing operation is performed, a phase is not changed surely. |
