| 摘要 |
PURPOSE: To prevent oscillation in output current from an inverter without limiting an output frequency of the inverter, by using a PWM signal generating nit for feeding a PWM signal to the inverter after an output frequency as an output from a frequency setting unit and an output command from an output command value setting unit are entered. CONSTITUTION: A current oscillation detecting unit 12 judges whether oscillation in output current is caused or not on the basis of an inverter output current fed through a second signal line 15. a signal of judgment is entered in an output voltage command value setting unit 11 through a first signal line 14. The output voltage command value setting unit 11 receives a frequency (f), a signal of oscillation or non-oscillation through the first signal line 14 and the inverter output current through the second signal line 15 so that an output voltage command (V) can be generated from these factors. After that, a PWM signal (Vabc ) is generated through the PWM signal generating unit 7 on the basis of the output voltage command (V) and the output frequency (f) and fed to an inverter 4. |
