To provide an inverter controller for driving an induction motor which controller is of small size, light weight, and low cost.
In the inverter controller, a reference value for direct-current voltage is divided by a detected value of direct-current voltage to derive a correction coefficient of PN voltage. A command value of motor voltage obtained from a motor voltage command generating means is multiplied by the correction coefficient of PN voltage which is the output value of a PN voltage correcting means to correct the command value of motor voltage and generate a corrected command value of motor voltage. When a correction coefficient of PN voltage is derived, the inverter controller is provided with two modes: a first mode in which 1 is set for the correction coefficient of PN voltage, and used in the case that the detected value of direct-current voltage is equal to or higher than the reference value for direct-current voltage; and a second mode in which the value obtained by dividing the reference value for direct-current voltage by the detected value of direct-current voltage is set for the same.
KAWACHI MITSUO
SUGIMOTO TOSHIHIRO
Masahiro Ishino
Kawabata Junichi
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