| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the capability and reliability of a harmonic restraint circuit by realizing suppression of switching unbalance. <P>SOLUTION: The harmonic restraint circuit comprises a circuit for rectifying the AC voltage from an AC power supply into a DC voltage, a capacitor for smoothing the rectified DC bus voltage, a reactor connected with each phase of the AC power supply, a means for short-circuiting the AC power supply through the reactor, a means for detecting the voltage of the AC power supply, and a means for controlling the short circuit means to perform short circuit operation in a switching pattern generated through internal operation only once or several times per half period of the AC power supply at a timing determined with reference to a power supply signal from the power supply voltage detecting means wherein the internal operation frequency fc of the control means is set equal to 2k (k: a positive integer) times of the AC power supply frequency fs. <P>COPYRIGHT: (C)2004,JPO |
