Inverter control apparatus

摘要

An inverter control apparatus includes a current detector for detecting currents of two phases from among output currents of an inverter that drives an induction motor, a current coordinate converter for converting currents detected by the current detector to a torque current component and an exciting current component, a computing device for computing the output frequency of the inverter corrected on the basis of a discrepancy proportional to the difference between an exciting current set value and an exciting current by using the torque current component and the exciting current component obtained by the current coordinate converter and for computing a torque voltage component and an exciting voltage component of the output voltage in synchronization with this output frequency, a voltage coordinate converter for converting the torque voltage component and the exciting voltage component computed by the computing device to a three-phase AC voltage of the output frequency of the inverter, and a PWM controller for generating switching control signals of the inverter on the basis of the three-phase AC voltage obtained by the voltage coordinate converter.