| 摘要 |
PURPOSE:To eliminate variation in measured values of output current due to impedance unbalance by calculating an amount of voltage drop due to unbalance of main circuit impedance for each phase and correcting each phase voltage command value on the basis of said calculated amounts. CONSTITUTION:A computing element 26 is provided for the purpose of calculating values of amplitude and phase resulting from current feedback from torque current feedback and flux current feedback outputted from a three phase-two phase converter 25. Said current feedback amplitude value is inputted to impedance correction circuits 48-50. Likewise, said current feedback phase value from the computing element 26 is added to a flux position signal being an output of integrator 43 and inputted to the impedance correction circuits 48-50. Further, a primary frequency is also inputted to the impedance correction circuits 48-50 and an amount of voltage drop due to impedance unbalance is calculated on the basis of said respective input values.
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