PGLESS VECTOR CONTROLLER FOR AC MOTOR

摘要

PROBLEM TO BE SOLVED: To stabilize the operation at low speed and regeneration even in an induction motor of very small slip frequency, in PGless vector control.

SOLUTION: A velocity command control circuit 37 uses a value larger in absolute value by a given value than the velocity command value ωr* instructed by a command generator 34 as the velocity command value ωr* to be inputted into a speed control unit 31 in case that an AC motor 2 is at low speed and it has detected that the codes of the velocity command value ωr* and a torque current command value Iq* are different from each other. Accordingly, by the velocity command value ωr* automatically becoming a large value at low speed and regeneration, the operation frequency rises, and the operation at low speed and regeneration can be stabilized even in the induction motor which is very small in slip frequency.

COPYRIGHT: (C)2004,JPO