| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent overheat of a capacitor prepared in parallel with a DC power supply on an input side of a DC/DC converter and of a reactor of the DC/DC converter. <P>SOLUTION: When a temperature Tw of a cooling liquid which cools the DC/DC converter is a set temperature T1 or below in a step S201, a value of a flag F1 is set to 0 in a step S202 and a frequency fc of a reference carrier is set to a high carrier frequency fh or a low carrier frequency fl on the basis of a temperature Tt of a power transistor. On the other hand, when a temperature Tw of the cooling liquid exceeds the set temperature T1 in the step S201, a value of the flag F1 is set to 1 in a step S203 and a frequency fc of the reference carrier is set to the high carrier frequency fh irrespective of a temperature Tt of the power transistor, thereby use of the low carrier frequency fl is inhibited. <P>COPYRIGHT: (C)2009,JPO&INPIT |
