Power converter circuit with ac output and at least one transformer

Abstract

A power converter circuit includes a synchronization circuit that is configured to generate at least one synchronization signal. A series circuit includes a number of converter units configured to output an output current. At least one of the converter units includes a transformer and is configured to generate an output current such that a frequency or a phase of the generated output current is dependent on the synchronization signal.

What is claimed is: 
     
         1 . A power converter circuit, comprising:
 a synchronization circuit configured to generate at least one synchronization signal; and   a series circuit comprising a plurality of converter units configured to output an output current;   wherein at least one of the plurality of converter units comprises a transformer and is configured to generate an output current such that a frequency or a phase of the generated output current is dependent on the synchronization signal.   
     
     
         2 . The power converter circuit of  claim 1 ,
 wherein the power converter circuit is configured to receive an external voltage; and   wherein the synchronization circuit is configured to generate the synchronization signal based on a voltage level of the external voltage.   
     
     
         3 . The power converter circuit of  claim 2 , wherein the synchronization circuit is configured to generate the synchronization signal such that there is a phase difference between the external voltage and the synchronization signal. 
     
     
         4 . The power converter circuit of  claim 3 , wherein the phase difference is substantially equal to zero. 
     
     
         5 . The power converter circuit of  claim 1 , wherein the at least one of the plurality of converter units comprises:
 a first converter configured to receive a direct voltage and to output a direct voltage; and   a second converter configured to receive the direct voltage output by the first converter and to generate the output current.   
     
     
         6 . The power converter circuit of  claim 5 , wherein the first converter comprises a topology selected from the group consisting of:
 a flyback converter topology;   a two-transistor forward (TTF) converter topology;   a phase-shift zero-voltage switching (PS ZVS) converter topology; and   an LLC converter topology.   
     
     
         7 . The power converter circuit of  claim 1 , wherein the at least one of the plurality of converter units comprises a converter configured to receive a direct voltage and to output a rectified current based on the synchronization signal. 
     
     
         8 . The power converter circuit of  claim 7 , wherein the at least one of the plurality of converter units further comprises an unfolding bridge configured to receive the rectified current and to generate the output current. 
     
     
         9 . The power converter circuit of  claim 7 , further comprising an unfolding bridge coupled to the series circuit. 
     
     
         10 . The power converter circuit of  claim 7 , wherein the converter comprises a topology selected from the group consisting of:
 a flyback converter topology;   a two-transistor forward (TTF) converter topology;   a phase-shift zero-voltage switching (PS ZVS) converter topology; and   an LLC converter topology.   
     
     
         11 . The power converter circuit of  claim 1 , wherein the plurality of converter units share one transformer. 
     
     
         12 . A method, comprising:
 generating a synchronization signal by a synchronization circuit;   outputting an output current by a series circuit that comprises a plurality of converter units, wherein at least one of the plurality of converter units comprises a transformer;   generating an output current by at least one of the plurality of converter units such that a frequency or a phase of the generated output current is dependent on the synchronization signal.   
     
     
         13 . The method of  claim 12 , further comprising receiving an external voltage, wherein the synchronization signal is generated based on a voltage level of the external voltage by the synchronization circuit. 
     
     
         14 . The method of  claim 13 , wherein the synchronization signal is generated such that there is a phase difference between the external voltage and the synchronization signal by the synchronization circuit. 
     
     
         15 . The method of  claim 14 , wherein the phase difference is substantially equal to zero. 
     
     
         16 . The method of  claim 12 , further comprising:
 receiving a direct voltage by a first converter in one of the plurality converter units;   outputting a direct voltage by the first converter; and   receiving the direct voltage from the first converter by a second converter in one of the plurality of converter units and generating the output current by the second converter.   
     
     
         17 . The method of  claim 16 , wherein the first converter comprises a topology selected from the group consisting of:
 a flyback converter topology;   a two-transistor forward (TTF) converter topology;   a phase-shift zero-voltage switching (PS ZVS) converter topology; and   an LLC converter topology.   
     
     
         18 . The method of  claim 12 , further comprising receiving a direct voltage and outputting a rectified current based on the synchronization signal by a converter in one of the plurality converter units. 
     
     
         19 . The method of  claim 18 , further comprising receiving the rectified current and generating the output current by an unfolding bridge. 
     
     
         20 . The method of  claim 19 , wherein the converter comprises a topology selected from the group consisting of:
 a flyback converter topology;   a two-transistor forward (TTF) converter topology;   a phase-shift zero-voltage switching (PS ZVS) converter topology; and   an LLC converter topology.   
     
     
         21 . The method of  claim 12 , wherein the plurality of converter units share one transformer.