| 摘要 |
PROBLEM TO BE SOLVED: To shorten the time for detecting phase unbalance. SOLUTION: This control device feeds variable frequency and variable voltage AC power to be outputted from a power converter 13 to control drive induction motors 14 to 17. The device is provided with current detecting means 18 to 25, which detects the phase currents of the induction motors 14 to 17, torque calculating circuits 29 to 32, which vector calculate the torques of the induction motors 14 to 17 from command voltages and phase currents with respect to the induction motors 14 to 17, and an unbalance detecting means 42, which outputs an unbalance detection signal, when the calculated torque exceeds a predetermined set value. |
