SOFT SWITCHING ACTIVE SNUBBER

摘要

A soft switching device (50) for electric power switching applications includes a switching element (52) and a soft switching active snubber (60). The soft switching active snubber (60) includes a capacitor (64), a rectifier (62) and a soft switching active reset circuit (70). The capacitor (64) connects in series with the rectifier (62) and both of which connects across the switching element (52). The soft switching active reset circuit (70) connected across the rectifier (62) as well as the capacitor (64), is responsive to a reset signal for active resetting of the capacitor (64) within the normal switching cycle of the switching element (52). Energy absorbed by the capacitor (64) is recovered to the input voltage source or to the load. This occurs contemporaneous with the power switching operation of the switching element (52). With the active snubber (60), soft switching is provided for both the switching element (52) and a snubber switch (72) within the active reset circuit (70), for an efficient and reliable circuit operation. The active snubber (60) also allows additional controls for implementing an intelligent soft switching device (50). The soft switching device (50) is a complete self-contained circuit. Its operation does not depend on any external circuit components. It can be used as an efficient, reliable, versatile and intelligent power switch in any kind of power switching applications. The active snubber (60) and soft switching device (50) introduce a new type of standard component for power electronics. They can be used in series or in parallel. The active snubber (60) can also provide stress relief for a diode, a switching circuit and a mechanical switch.