| 摘要 |
PROBLEM TO BE SOLVED: To prevent an uncontrollable condition for regeneration in a low speed range by limiting torque partial current at the maximum regeneratable torque. SOLUTION: In a speed sensor-less vector control method, he primary current of an induction motor 1 is detected to obtain the primary current detection value on the coordinate of a stator whose number of phase has been converted by a 3-phase-2- phase converter 14. The primary current detection value, the primary voltage command value of a motor on the stator coordinate, and a speed estimated value are inputted in one-dimensional magnetic flux observer. The secondary magnetic flux estimated value and the primary current estimated value in the stator coordinate are estimated, and a motor speed estimated value is calculated according to an adaptive adjusting expression for operating and estimating a speed Wr<ξ> of the motor 1, based on an estimated error signal obtained by comparing the primary current estimated value with the primary current detection value with a speed adaptive mechanism 7 to estimate the speed of the motor 1. A regenerative torque current limiter 10 is provided for a torque current command input part, and the limit value of the regenerative torque current limiter is called from a limiter table 11 to obtain operable torque partial current. |
