Power converter control for reducing EMI noise by temporally changing the PWM carrier frequency

摘要

PROBLEM TO BE SOLVED: To provide the controller and control method of a power converter in which noise level for a predetermined frequency band can be further reduced while reducing the noise level over a wide frequency band.;SOLUTION: In the controller 13 of an inverter system 1, a carrier frequency variable section 12 varies the frequency of a control signal based on a waveform varying periodically in a first frequency range fc1-fc2(fc1fc2) and in a second frequency range fc3-fc4(fc3fc4). The frequencies fc1 and fc4 are determined to be an integer n satisfying the following inequalities n×fc2≤fs-Δfs and fs+Δfs≤n×fc3 for a predetermined frequency band fs±Δfs, and satisfying the inequalities (n-1)×fc4≤n×fc2 and n×fc3≤(n+1)×fc1 for fc2 and fc3.;COPYRIGHT: (C)2008,JPO&INPIT