| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a voltage converter for an electrical vehicle that performs step up and down and a current control technique for preventing overheating that is suitable for a voltage converter using a chip in which switching elements and diodes connected in inverse-parallel are mounted in one substrate.SOLUTION: A voltage converter has two chips, and each chip has a temperature sensor for measuring the temperature of the chip. A current upper limit value is associated with each of measurement temperatures of the two temperature sensors in advance. A controller determines a duty ratio (D) so that current flowing in a reactor is not more than smaller one of the current upper limit value corresponding to one measurement temperature and the current upper limit value corresponding to the other measurement temperature. The controller stores two sets of the current upper limit value corresponding to the measurement temperature of the one temperature sensor and the current upper limit value corresponding to the measurement temperature of the other temperature sensor, and switches the current upper limit values of the two sets according to the direction of the current flowing in the reactor.</p> |
