| 摘要 |
PROBLEM TO BE SOLVED: To avoid conversion of turn-on relaxation circuit energy into heat through a simple method. SOLUTION: The circuit and method are for relaxing turn-on of the interruptible power switch of a three-point converter. A turn-on mitigation circuits are formed at upper and lower bridge branches, respectively, and this circuit is provided with a turn-on mitigation choke coil, an overvoltage limiting capacitor, and an auxiliary switch comprising, for example, an interruptible power switch and an anti-parallel diode. To prevent energy conversion into heat, these elements are switched so that rectification is performed when the main switch of the interruptible power switch is turned off. The switching timing of the interruptible power switch is appropriately controlled and thereby charge adjustment is accomplished in the overvoltage limiting capacitor for a long time. |
