Patent ID: 7957164
Filing Date: 2011-06-07
Classification: H02M,Y02B

Abstract:
1. A power device for supplying an electric power to a load in which an electrostatic capacity discontinuously changes, the power device comprising: a converter part for converting an AC voltage to a DC voltage; an inverter part that has a switching element and a circulating current diode connected in parallel with the switching element and converts the DC voltage outputted from the converter part to an AC voltage; a transformer that has a first inductance forming a series resonance circuit with the electrostatic capacity of a load and converts the AC voltage outputted from the inverter part; and a second inductance connected to an output part of the inverter part, wherein the second inductance is connected in parallel with the transformer, wherein the second inductance is connected in parallel with the inverter part, and wherein the value of the second inductance is set so that when the switching element is turned on to apply a backward voltage to the circulating current diode, and a direction of a current supplied to the transformer is the same as a forward direction of the circulating current diode, then an absolute value of the current supplied to the second inductance is to be larger than an absolute value of the current supplied to the transformer.