| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor drive system employing a diode converter in which primary voltage saturation of a motor caused by sudden load applied thereto during occurrence of the biting of a rolling mill is avoided, and unstable control or trip of an inverter affected by the voltage saturation is prevented. <P>SOLUTION: A motor drive system comprises: a motor 11; a diode converter 22 which is DC power for an inverter; a motor control device 23 which performs variable speed control of the motor 11 using the inverter, and performs control for weakening magnetic field; a primary voltage detection unit 13 which detects primary voltage outputted by the motor control device 23; a modulation rate variation detection unit which detects a timing of variation and the variation amount when it is predicted that requested modulation rate of the inverter is varied; and a correction voltage unit 25 which calculates a variation amount of the primary voltage on the basis of the variation amount of the modulation rate detected by the modulation rate variation detection unit. The motor control device 23 calculates a d-axis field current suppression amount to perform the control for weakening magnetic field on the basis of the primary voltage and the variation amount thereof. <P>COPYRIGHT: (C)2013,JPO&INPIT |
