| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that when insulation failure, etc. occurs between an on-vehicle high voltage system such as a motor generator 10 and the car body, common mode noise increases, so that if the noise is superposed on a PWM signal SV which has had information on input voltage Vin superposed thereon, a DC-DC converter CNV is forced into stopping. <P>SOLUTION: In a PWM processing unit 32, the carrier frequency of a PWM signal SV is made to be a frequency f1 when an input voltage Vin is within an allowable range, or made to be a frequency f2 when out of the allowable range. In a control unit 40, when, although the PWM signal SV is a signal at the frequency f1, an input voltage obtained by decoding the PWM signal SV falls outside the allowable range, a Duty value D of a main switching element Q1 is limited to a fixed value, and, while so doing, voltage conversion processing is continued. <P>COPYRIGHT: (C)2013,JPO&INPIT |
