| 摘要 |
It is an object of the invention to provide an inverter apparatus capable of instantaneously limiting a current to prevent the breakdown of a device and operating an electric motor efficiently and stably. The invention provides an inverter apparatus for carrying out a PWM modulation to output a voltage based on a voltage command vector obtained from a frequency command value Fref and a voltage command value calculated from the frequency command value by a V/f operation 7, comprising current detecting means 12a for detecting a current vector having a magnitude Il of a current and a current phase &thetas;i, voltage limitation value calculating means 15 for calculating a voltage limitation value DELTA V which is proportional to an excess when the magnitude of the current exceeds a current limitation value Imax, voltage limitation vector calculating means 16 for converting the voltage limitation value into voltage limitation vectors DELTA Vq and DELTA Vd based on the current phase, voltage correcting means 17 for adding the voltage limitation vector to the voltage command vector, and acceleration correcting means 11 for correcting an acceleration command of a frequency based on the voltage limitation value and the current phase. <IMAGE> |
