| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric motor control system for properly avoiding a dangerous state where a DC electric motor runs out of control due to the rapid decrease in a load in ACR (torque control) mode when the system is applied to a loading/unloading machine. SOLUTION: In a thyristor Leonard device, an ASR (speed control) control amplifier 10 has a function of current correction amplifier at ACR control when performing the drive and regeneration control of a DC electric motor. More specifically, a current setting is added to the output of a limiter 11 for limiting the output of the ASR control amplifier 10, and the difference between the addition result and the current detection is inputted to an ACR control amplifier 12. At ASR control, current is set to zero and a limit value is set to 150% of the normal limited value for both the drive and regeneration sides. At the ACR control, a current command is given for setting the ACR control to the basic control. The limit value at this time is set to zero and an arbitrary value for the zero and regeneration sides. Also, a limited speed is commanded by speed setting. |
