| 摘要 |
PURPOSE:To eliminate the need for a semiconductor switch having high breakdown voltage by connecting a voltage clamp circuit, comprising a clamp diode and a clamp capacitor, in parallel with a snubber capacitor. CONSTITUTION:This snubber energy recovering circuit is different from a conventional circuit in that a positive pole side voltage clamp circuit 31, comprising a clamp capacitor(CC) 31C and a clamp diode(CD) 31D, is connected in parallel with a snubber capacitor(SC) 8C. A third energy recovery circuit 42, comprising a third recovery diode 42D and a third recovery reactor 42L, is inserted between the CC 31C and the negative pole side of a DC power supply 2. A negative pole side voltage clamp circuit 41, comprising a CC 41C and a CD 41D, is connected in parallel with an SC 9C. A fourth energy recovery circuit 32. comprising a fourth recovery diode 32D and a fourth recovery reactor 32L, is inserted between the CC 41C and the positive pole side of the DC power supply 2. When the voltage of the SC 9C exceeds that of the CC 41C, the CD 41D is conducted and the voltage of a semiconductor switch 4 is restricted to the same level as that of the CC 41C. |
