PHASE CURRENT DETECTION APPARATUS FOR INVERTER, INCLUDING RECTIFIER UNIT, SWITCHING UNIT, DETECTION UNIT, FILTER, ANALOG-DIGITAL CONVERTER, PHASE CURRENT AVERAGING UNIT, CONTROL UNIT, AND PULSE WIDTH MODULATION SIGNAL

摘要

PURPOSE: A phase current detection apparatus is provided to detect stable phase current regardless of the size of output voltage, by reading phase current and calculating averages for several times during zero voltage or effective voltage switching. CONSTITUTION: A phase current detection apparatus comprises a rectifier unit(10) for rectifying AC power; a switching unit(11) for taking, as an input, rectifying signal from the rectifier unit, and performing a switching operation by a pulse width modulation signal; a detection unit(12) for detecting the phase current output from the switching unit; a filter(13) for filtering the phase current detected by the detection unit; an analog-digital converter(14) for taking, as an input, phase current filtered by the filter, and converting the filtered phase current into a digital signal in accordance with a control signal; a phase current averaging unit(51) for averaging the digital signal output from the analog-digital converter; a control unit(15) for taking, as an input, signal output from the phase current averaging unit, outputting a control signal corresponding to the input signal, and outputting a control signal for synchronizing output of the analog-digital converter; and a pulse width modulation unit(16) for outputting a pulse width modulation signal for controlling switching of an inverter in accordance with the control signal output from the control unit.