| 摘要 |
PURPOSE:To realize a stable and high performance controller without disabling control and generating stall of motor even under a large variation of load by providing a phase controller for controlling the maximum value of a phase difference angle delta and thereby deciding the maximum phase difference angle deltamax to be limited depending on the characteristic of synchronous motor. CONSTITUTION:A phase limiter 20 outputs an angle delta' having completed limitation process of + or -deltamax relative to an output of a magnetic flux arithmetic unit 6. A current reference arithmetic unit 7 calculates current references i'd, i'q of the d and q axes from a torque current iT, and an output delta' of phase limiter using the following equations. i'd=-i'T.sindelta, i'q=iT.condelta. A value of deltamax is an ideal maximum value determined by various constants of motor and an overload characteristic and an internal phase different angle of motor never exceeds such maximum value under any condition. Therefore, a current phase determined by the equations (6), (7) can be instructed so that a torque current orthogonally crosses the calculated magnetic flux even under the maximum overload condition and thereby the maximum torque can be outputted. |
