| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power conversion device capable of surely detecting an open phase of a multiphase AC power supply irrespective of whether an operation load is heavy or light, and suppressing manufacturing costs required for the detection. <P>SOLUTION: A power conversion device comprises: a rectification unit 2 which rectifies AC of a three-phase AC power supply 1 to DC; a smoothing unit 3 which smooths a pulsating flow rectified by the rectification unit 2; an inverter unit 3 which converts the DC smoothed by the smoothing unit 3 to AC; and an open-phase detection unit 7 which detects a loss of any phase of the three-phase AC power supply 1. The open-phase detection unit 7 detects a ripple voltage included in an output voltage of the smoothing unit 2, compares the ripple voltage with a reference value, and outputs the comparison result. The open-phase detection unit 7 detects electric power supplied to a load 6 connected to the inverter unit 4 and changes (corrects) the reference value used to compare the ripple voltage according to the detected electric power. <P>COPYRIGHT: (C)2013,JPO&INPIT |
