| 摘要 |
PURPOSE:To obtain the torque detecting device at low cost by a method wherein a DC current detector, a rotational angle speed detector for motor and an inverter DC voltage detector are employed, and two operational amplifiers and a multiplier are combined together to the above detectors. CONSTITUTION:The induction motor 15 is driven by a converter 12 and a current type inverter device containing an inverter 14. Then, the inverter DC voltage detected by a detector 17 is passed through a spike voltage cutting circuit 18, and a DC current is detected by a detector 19, the resistance drop component caused by a stator and a rotor is subtracted using a subtracting machine 21, and the result is given to a dividing machine 24 through the intermediary of a multiplier 22. On the other hand, torque tau0 is obtained by forming an arithmetic operation applying the output of a rotating angle speed detector 16 to a dividing machine 24 through the intermediary of a multiplier 22. Accordingly, the torque can be detected by merely providing two circuits with the multiplier on the detector already installed, and the circuit for the device can be largely simplified. |
