| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the operation efficiency of a motor from dropping excessively due to the increase of the current ripple of each phase of currents estimated from the detected value of the current on the DC side of an inverter. <P>SOLUTION: A PWM signal generator 24 computes the current duration being the duration of each phase current Iu, Iv, and Iw at a DC link current IDC in single carrier cycle fc, and acquires the minimum current duration from the current duration of every phase current Iu, Iv and Iw. It sets a value, which is obtained by subtracting the duration of the minimum current from the specified time according to the detection stability time required for the actual detection state by a current sensor 14b on DC side to reach its specified stable state, as the phase difference of a three-phase carrier signal. <P>COPYRIGHT: (C)2007,JPO&INPIT |
