| 摘要 |
PROBLEM TO BE SOLVED: To obtain an inverter control apparatus by which the rated voltage of a lifting motor is increased up to a power-supply voltage and by which the costs of the lifting motor and of an inverter for drive are lowered, by a method wherein, even when the DC voltage of a main circuit is lowered due to a change in the power-supply voltage, the output voltage waveform of the inverter is not distorted. SOLUTION: The required DC voltage, of a main circuit, which is computed by a required-DC-voltage computing part 22 on the basis of a voltage instruction to be outputted from a current regulator(ACR) 17, and an actual DC voltage which is detected by a voltage detector 20 are compared by a comparison part 23, and their difference Δv is computed. Then, when the DC voltage of the main circuit becomes lower than the required DC voltage, the correction amount ΔΦof a magnetic-flux instruction Φo according to the difference Δv is computed by a magnetic-flux-correction-amount computing part 24, the magnetic-flux instruction Φo is corrected, an exciting current is adjusted downward, and the output voltage of an inverter is lowered so that a voltage waveform is not distorted. |
