Patent ID: 8542467
Filing Date: 2013-09-24
Classification: H02M

Abstract:
1. A switching device comprising: a plurality of semiconductor switching elements coupled in series, each of the plurality of semiconductor switching elements including a free wheel diode; a smoothing capacitor coupled in parallel with a direct current power source and the plurality of semiconductor switching elements, the smoothing capacitor smoothing an output of the direct current power source and supplying the smoothed output to the plurality of semiconductor switching elements; and a snubber circuit coupled between a first connecting point and a second connecting point in parallel with the plurality of semiconductor switching elements, wherein an inductance of a first channel provided from the first connecting point to the second connecting point through the smoothing capacitor is equal to or more than 10 times as large as an inductance of a second channel including the plurality of semiconductor switching elements and the snubber circuit so as to reduce a power dissipation associated with a recovery current of the free wheel diode.