Patent ID: 7411802
Filing Date: 2008-08-12
Classification: H02J,H02M,Y02E

Abstract:
1. A method of converting a direct current voltage of a source of direct current voltage into an alternating current voltage at a frequency through a bridge circuit comprising four switching elements (V 1 -V 4 ) and four free-wheeling elements (D 1 -D 4 ), said four switching elements (V 1 , V 2 , V 3 and V 4 ) being gated in such a way, that one corresponding switching element (V 1 , V 3 ) of a first bridge half is gated at at a mains frequency and one corresponding switching element (V 2 , V 4 ) of a second bridge half is gated at a high clock rate, a direct current voltage circuit, an alternating current voltage circuit and a plurality of free-wheeling phases being provided, characterized in that the alternating current voltage circuit is decoupled from the direct current voltage circuit during the free-wheeling phases by means of the switching element (V 2 ) or (V 4 ) and an additional switching element (V 5 ) disposed in the direct current voltage circuit which defines a commutation circuit, a free-wheeling current flowing through one of said free-wheeling elements (D 1 , D 3 ) of the first bridge half in said bridge circuit when in the decoupled state, in that the four switching elements (V in that the additional switching element (V in that the switching elements (V in that harmonics are reduced in the alternating current voltage circuit through at least one reactor.