Motor drive device for determining cause of DC link voltage fluctuation

摘要

Problem to be solved: to realize a motor driving device capable of easily and accurately determining the cause of a drastic drop or increase in the DC link voltage.The motor driving apparatus 1 includesA rectifier 11 which converts AC power on the AC input side into DC power and outputs it to a DC linkAn inverse converter 12 for converting DC power of DC link to AC power for motor driveA DC link voltage detector 13 for detecting a DC link voltage andAn input current detecting section 14 for detecting an input current to the rectifier 11 andA DC link voltage comparator 15 compares the DC link voltage with each of the first and second voltage thresholdsA current comparator 16 compares the input current and the current thresholdIf the DC link voltage is lower than the first voltage threshold or the DC link voltage is high, the second voltage threshold is highIf the input current is lower than the current threshold, it is determined that the first abnormality has occurred.If the input current is equal to or greater than the current threshold, the abnormality detection unit 17 determines that the second abnormality has occurred.Diagram