Parallel-connected resonant converter circuit and controlling method thereof

Abstract

The configurations of a parallel-connected resonant converter circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.

1 . A parallel-connected resonant converter circuit, comprising:
 a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.   
   
   
       2 . A circuit according to  claim 1  further comprising a DC power source having a positive and a negative terminals, an output capacitor, and a plurality of input capacitors, each of the plurality of input capacitors has a first and a second terminals and is electrically parallel-connected to the two input terminals of a corresponding one of the plurality of resonant converters, wherein the output capacitor is electrically parallel-connected to the two output terminals of each the resonant converter, and the series-connected resonant converters are connected in paralleled with the DC power source at the positive and the negative terminals. 
   
   
       3 . A circuit according to  claim 1 , wherein each the resonant converter is one of a series resonant DC/DC converter and a parallel resonant DC/DC converter. 
   
   
       4 . A circuit according to  claim 3 , wherein the series resonant DC/DC converter is an LLC series resonant DC/DC converter. 
   
   
       5 . A circuit according to  claim 3 , wherein the parallel resonant DC/DC converter is an LCC parallel resonant DC/DC converter. 
   
   
       6 . A circuit according to  claim 1 , wherein the plurality of resonant converters are operating at substantially the same frequency. 
   
   
       7 . A circuit according to  claim 1 , wherein the plurality of resonant converters are operating under an interleaved mode. 
   
   
       8 . A parallel-connected resonant converter circuit, comprising:
 a first resonant converter having two input terminals and two output terminals; and   a second resonant converter having two input terminals and two output terminals, wherein the two input terminals of the second resonant converter are electrically series-connected with the two input terminals of the first resonant converter, and the two output terminals of the second resonant converter are electrically parallel-connected with the two output terminals of the first resonant converter.   
   
   
       9 . A circuit according to  claim 8  further comprising a DC power source having a positive and a negative terminals, an output capacitor and a first and a second input capacitors, wherein the first and the second input capacitors are electrically parallel-connected with the two input terminals of the first and the second resonant converters respectively, the output capacitor is electrically parallel-connected with the two output terminals of the first and the second resonant converters, each of the first and the second input capacitors has a first and a second terminals, the first terminal of the first input capacitor is coupled to the positive terminal, the second terminal of the first input capacitor is coupled to the first terminal of the second input capacitor, and the second terminal of the second input capacitor is coupled to the negative terminal. 
   
   
       10 . A circuit according to  claim 8 , wherein the first and the second resonant converters are operating under an interleaved mode. 
   
   
       11 . A circuit according to  claim 8 , wherein each of the first and the second resonant converters is an LLC series resonant DC/DC converter. 
   
   
       12 . A circuit according to  claim 11 , wherein the first and the second resonant converters operate with 90° phase shifted. 
   
   
       13 . A circuit according to  claim 8 , wherein the first and the second resonant converters are operating at substantially the same frequency. 
   
   
       14 . A controlling method for a parallel-connected resonant converter circuit, wherein the circuit comprises a plurality of resonant converters, each of which has two input terminals and two output terminals, all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected, comprising steps of:
 (a) causing an input current flowing through the two input terminals of a specific one of the plurality of resonant converters to rise when an output current flowing through the two output terminals of the specific resonant converter rises;   (b) causing an input voltage across the two input terminals of the specific resonant converter to decrease when the input current flowing through the two input terminals of the specific resonant converter rises;   (c) causing an input voltage across the two input terminals of at least one of the remaining ones of the plurality of resonant converters to rise when the input voltage across the two input terminals of the specific resonant converter decreases;   (d) causing an output current flowing through the two output terminals of at least one of the remaining resonant converter to rise when the input voltage across the two input terminals of at least one of the remaining resonant converter rises; and   (e) reaching the balance between the specific resonant converter and at least one of the remaining of resonant converters when a ratio between the output current flowing through the two output terminals of the specific resonant converter and the output current flowing through the at least one of the remaining resonant converters equals to a ratio between a reciprocal of a DC voltage gain of the specific resonant converter and a reciprocal of a DC voltage gain of the at least one of the remaining resonant converter.   
   
   
       15 . A method according to  claim 14 , wherein the plurality of resonant converters comprise a first and a second resonant converters, the specific resonant converter is the first resonant converter and the remaining one is the second resonant converter. 
   
   
       16 . A method according to  claim 14 , wherein the plurality of resonant converters are operating under an interleaved mode. 
   
   
       17 . A method according to  claim 14 , wherein the plurality of resonant converters are operating at substantially the same frequency.