| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve backup by commercial power supply operation upon failure of an inverter in a refrigeration system mounting an inverter. <P>SOLUTION: The motor of a compressor driven through an inverter is an MS motor. Motor temperature being followed by the MS motor during operation at the commercial power supply frequency is sustained by a liquid ejection mechanism, and the current does not exceeds a predetermined limit level because of protective shut-down by a current sensor. When instant voltage drop is detected due to momentary service interruption, power supply to a compressor operating synchronously at the commercial power supply frequency is interrupted temporarily and the compressor is restarted after rotation of the compressor motor stopped completely thus preventing overcurrent. <P>COPYRIGHT: (C)2008,JPO&INPIT |
