| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide power conversion equipment which reduces the peak level of noise sufficiently by reducing irregularities formed in the spectra of higher harmonics of a carrier frequency, in temporally changing the value of the carrier frequency discretely. <P>SOLUTION: In the power conversion equipment, which converts input power into a three-phase AC by a PWM inverter 2, a controller 5, which controls the PWM inverter 2, includes a carrier frequency changer 10, which temporally changes the frequency of carrier waves in PWM control discretely and periodically, and a carrier output part 11, which outputs carriers to PWM comparators 8a, 8b, and 8c. The carrier frequency changer 10 determines the variable range of the carrier frequency so that the frequency spectra of the higher harmonics in each degree of carriers may continue, in a desired frequency band. <P>COPYRIGHT: (C)2010,JPO&INPIT |
