| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a driving device for a railway vehicle for cold district which melts a coolant while preventing temperature rise of a switching element even when the coolant of a cooler is frozen, and has desired cooling performance without changing the size of the cooler.SOLUTION: When it is determined that a coolant of a cooler might be frozen, a current is sent to a switching element for a certain period of time to heat the switching element. Two kinds of sensors for measuring the temperature on a heat receiving part side and the temperature on a heat releasing part side are installed on the cooler. On the basis of the temperature on the heat receiving part side, the temperature on the heat releasing part side and heat quantity of the switching element obtained from a current, heat resistance of the entire cooler is calculated, and it is determined that the cooler is frozen if the value is equal to or higher than a constant value. When it is determined that the coolant is frozen, heat resistance of the cooler is calculated, and a warm-up operation is started. Moreover, a current to be sent to the switching element is calculated based on the calculated heat resistance, and the flowing current of the switching element is so controlled that it becomes equal to or lower than the calculated value during the warm-up operation.</p> |
