| 摘要 |
PURPOSE:To control stably the entire region of load state by compensating the gain variation of a control system produced by the impedance change of a load circuit by means of a correction signal operating device. CONSTITUTION:Plural inverters are connected to the output side of a common converter and each inverter drives an induction motor individually. A DC voltage is inputted to the inverter via a main circuit contactor 23 and an input capacitor 22, the voltage is converted into a variable voltage/variable frequency and the result is fed to the said motor. In this case, a voltage feedback signal VFBK, a current feedback signal IFBK and an operating signal 6 representing the on/off state of the contactor 23 are inputted to a correction signal operating device 5 so as to operate the load resistance component of the converter and also the load capacitor component is operated from the capacitor 22. Then a function cancelling the main circuit transfer function is operated and the result is inputted to a gain correction signal 7 as a voltage controlling operator VC. |
