| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect that a lock occurs in a compressor without using the neutral electric potential of a motor, and to detect the lock position. <P>SOLUTION: An inverter is controlled to apply the harmonic voltage to a motor, and the stop position is detected from the current locus. The inverter is controlled and the motor is DC-excited to rotate the motor in the forward direction by the electric angle of 90°. The inverter is controlled to apply the harmonic voltage again to the motor, and the stop position is detected from the current locus. It is determined whether or not the lock occurs based on whether or not the difference between the first and second stop positions is not more than a predetermined threshold. <P>COPYRIGHT: (C)2004,JPO |
