| 摘要 |
PROBLEM TO BE SOLVED: To lower the switching frequency of an inverter and lessen the switching loss, to suppress heat generation by forcedly switching the pulse mode into another pulse mode one stage lower than before, under such a situation that the train speed is balanced. SOLUTION: With the electric car, the pulse mode of an inverter is set in multistages by pulse mode setting means 41a-41e, when driving a motor for drive of the train by an inverter of variable frequency variable voltage control. Now, when the train speed is balanced in such a situation while the train is going up an accent, a speed balance judging means Pf1 judges that the train speed is balanced, and based on this judgment result, the pulse mode forcedly switching means 44a-44b and 45a-45b forcedly switch the pulse modes set by the pulse mode setting means 41a-44d over to a pulse mode, one stage lower than before. |
