| 摘要 |
PROBLEM TO BE SOLVED: To control an over-voltage based on voltage unbalance depending on the difference of turning off timing of each element in view of preventing breakdown of elements on the occasion of forming each arm of a power converting circuit with serial connection of the voltage drive type elements. SOLUTION: In the case where each arm is formed of serial connection of two voltage drive type elements, since a voltage is applied only to voltage drive type element Q1 which is turned off earlier, for example, in an upper arm, when the over-voltage of Q1 is detected with the gate drive circuit GDU1, above problem can be solved by turning on again the element Q1. |
