| 摘要 |
PROBLEM TO BE SOLVED: To provide a system which has current control with excellent stability in regenerating, in an A.C. motor controller which always requires a compact size and highly efficient drive. SOLUTION: A vector phase θc is calculated, by a voltage/current phase difference calculating circuit 19, from both the voltage command value and primary current of an A.C. motor. This is inputted into the second voltage command circuit 20 and second voltage command value of d-axis and q-axis is calculated, using the vector phase θc and current deviation of d-axis and q-axis. By correcting the voltage command value on the basis of this value, the stability of a current control system is improved. As a result, stable current control can be obtained even in regenerating and field weakening control in the control of the A.C. motor. It is thus possible to provide a compact A.C. motor which can always conduct highly efficient driving. This A.C. motor controller is effective, especially for a crane (hoist) which uses power running/ regeneration, and for an electric car which must drive downhill for a long time. |
