A three-phase LLC transformer current sharing circuit

Abstract

The utility model provides a three -phase LLC transformer current sharing circuit, including transformer module, the primary side resonance module of connection in the primary side of transformer module and parallelly connected rectification module in the secondary side of transformer module, the transformer module includes first transformer, second transformer, third transformer, first transformer includes first secondary winding and second secondary winding, second transformer includes third secondary winding and fourth secondary winding, third transformer includes fifth secondary winding and sixth secondary winding, rectification module includes first rectification unit and second rectification unit, the utility model discloses can prevent the phenomenon that two windings of transformer secondary side are not current -sharing by adjusting the connection of transformer secondary winding, and the transformer secondary winding is not current -sharing to the phenomenon that the self -induction of transformer secondary winding is not asymmetric.

Description

Technical Field

[0001] This utility model relates to the field of current sharing, and more specifically, to a current sharing circuit for a three-phase LLC transformer. Background Technology

[0002] In a three-phase LLC circuit, the primary and secondary sides are connected in a star configuration, and a single transformer has one winding on the primary side and two windings on the secondary side. Due to the winding method, one of the secondary windings of the transformer may have an excessively high self-inductance. In a three-phase LLCI circuit, if the self-inductance of the two secondary windings of a single transformer is unbalanced, it will lead to uneven current distribution between the two secondary windings. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a current sharing circuit for a three-phase LLC transformer, which can realize the current sharing of the secondary winding of the transformer, in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by this utility model to solve its technical problem is: to construct a three-phase LLC transformer current sharing circuit, including a transformer module, a primary resonant module connected to the primary side of the transformer module, and a rectifier module connected in parallel to the secondary side of the transformer module. The transformer module includes a first transformer, a second transformer, and a third transformer. The first transformer includes a first secondary winding and a second secondary winding. The second transformer includes a third secondary winding and a fourth secondary winding. The third transformer includes a fifth secondary winding and a sixth secondary winding. The rectifier module includes a first rectifier unit and a second rectifier unit; The first end of any one of the first secondary winding, the third secondary winding, and the fifth secondary winding is connected to the second rectifier unit, and the first end of the remaining windings of the first secondary winding, the third secondary winding, and the fifth secondary winding is connected to the first rectifier unit. The first end of any one of the second secondary winding, the fourth secondary winding, and the sixth secondary winding is connected to the first rectifier unit, and the first end of the remaining windings of the second secondary winding, the fourth secondary winding, and the sixth secondary winding is connected to the second rectifier unit. In the current sharing circuit of the three-phase LLC transformer described in this utility model, the first end of the first secondary winding is connected to the first end of the second rectifier unit, the first end of the second secondary winding is connected to the first end of the first rectifier unit, the first end of the third secondary winding is connected to the second end of the first rectifier unit, the first end of the fourth secondary winding is connected to the second end of the second rectifier unit, the first end of the fifth secondary winding is connected to the third end of the first rectifier unit, and the first end of the sixth secondary winding is connected to the third end of the second rectifier unit. The second end of the first secondary winding is connected to the second end of the fourth secondary winding and the second end of the sixth secondary winding; The second end of the second secondary winding is connected to the second end of the third secondary winding and the second end of the fifth secondary winding.

[0005] In the current sharing circuit of the three-phase LLC transformer described in this utility model, the first end of the first secondary winding is connected to the first end of the first rectifier unit, the first end of the second secondary winding is connected to the second end of the second rectifier unit, the first end of the third secondary winding is connected to the second end of the second rectifier unit, the first end of the fourth secondary winding is connected to the second end of the first rectifier unit, the first end of the fifth secondary winding is connected to the third end of the first rectifier unit, and the first end of the sixth secondary winding is connected to the third end of the second rectifier unit. The second end of the first secondary winding is connected to the second end of the fourth secondary winding and the second end of the fifth secondary winding; The second end of the second secondary winding is connected to the second end of the third secondary winding and the second end of the sixth secondary winding.

[0006] In the current sharing circuit of the three-phase LLC transformer described in this utility model, the first end of the first secondary winding is connected to the first end of the first rectifier unit, the first end of the second secondary winding is connected to the second end of the second rectifier unit, the first end of the third secondary winding is connected to the second end of the first rectifier unit, the first end of the fourth secondary winding is connected to the second end of the second rectifier unit, the first end of the fifth secondary winding is connected to the third end of the second rectifier unit, and the first end of the sixth secondary winding is connected to the third end of the first rectifier unit. The second end of the first secondary winding is connected to the second end of the third secondary winding and the second end of the sixth secondary winding; The second end of the second secondary winding is connected to the second end of the fourth secondary winding and the second end of the fifth secondary winding.

[0007] In the three-phase LLC transformer current sharing circuit described in this utility model, the first rectifier unit includes a first diode, a second diode, a third diode, a fourth diode, a fifth diode, and a sixth diode; The anode of the first diode and the cathode of the second diode are connected to the first terminal of the first rectifier unit; the anode of the third diode and the cathode of the fourth diode are connected to the second terminal of the first rectifier unit; and the anode of the fifth diode and the cathode of the sixth diode are connected to the third terminal of the first rectifier unit. The cathodes of the first diode, the third diode, and the fifth diode are connected to the positive output terminal; The cathodes of the second diode, the fourth diode, and the sixth diode are connected to the negative output terminal.

[0008] In the three-phase LLC transformer current sharing circuit described in this utility model, the first rectifier unit further includes a first output capacitor and a first output resistor; The first output capacitor and the first output resistor are connected in series between the positive output terminal and the negative output terminal.

[0009] In the three-phase LLC transformer current sharing circuit described in this utility model, the second rectifier unit includes a seventh diode, an eighth diode, a ninth diode, a tenth diode, an eleventh diode, and a twelfth diode; The anode of the seventh diode and the cathode of the eighth diode are connected to the first terminal of the second rectifier unit; the anode of the ninth diode and the cathode of the tenth diode are connected to the second terminal of the second rectifier unit; and the anode of the eleventh diode and the cathode of the twelfth diode are connected to the third terminal of the second rectifier unit. The cathodes of the seventh diode, the ninth diode, and the eleventh diode are connected to the positive output terminal. The cathodes of the eighth diode, the tenth diode, and the twelfth diode are connected to the negative output terminal.

[0010] In the three-phase LLC transformer current sharing circuit described in this utility model, the second rectifier unit further includes a second output capacitor and a second output resistor; The second output capacitor and the second output resistor are connected in series between the positive output terminal and the negative output terminal.

[0011] In the three-phase LLC transformer current sharing circuit of this utility model, the primary side resonant module includes a first switching network, a second switching network, a third switching network, a first resonant unit, a second resonant unit, and a third resonant unit; The first terminal of the first switch network, the second switch network, and the third switch network are respectively connected to the positive input terminal, and the second terminal is respectively connected to the negative input terminal. The output terminal of the first switching network is connected to the first terminal of the primary winding of the first transformer via the first resonant unit; The output of the second switching network is connected to the first end of the primary winding of the second transformer via the second resonant unit; The output terminal of the third switching network is connected to the first terminal of the primary winding of the third transformer via the third resonant unit; The second end of the primary winding of the first transformer is connected to the second end of the primary winding of the second transformer and the second end of the primary winding of the third transformer.

[0012] In the three-phase LLC transformer current sharing circuit described in this utility model, the first switch network, the second switch network and the third switch network each include a switch tube half-bridge; The first resonant unit, the second resonant unit, and the third resonant unit each include a resonant capacitor and a resonant inductor connected in series with each other.

[0013] The current-sharing circuit of the three-phase LLC transformer of this utility model is implemented in which the first end of any one of the first, third, and fifth secondary windings is connected to the second rectifier unit, and the first ends of the remaining windings of the first, third, and fifth secondary windings are connected to the first rectifier unit; the first end of any one of the second, fourth, and sixth secondary windings is connected to the first rectifier unit, and the first ends of the remaining windings of the second, fourth, and sixth secondary windings are connected to the second rectifier unit; by adjusting the connection method of the transformer's secondary windings, current sharing between the two secondary windings of the transformer is achieved, thereby preventing the phenomenon of uneven current sharing between the two secondary windings of the transformer caused by the self-inductance asymmetry of the transformer's secondary windings. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a schematic block diagram of a preferred embodiment of the current sharing circuit of a three-phase LLC transformer of this utility model; Figure 2 This is a circuit diagram of the first preferred embodiment of the three-phase LLC transformer current sharing circuit of this utility model; Figure 3 This is a circuit diagram of a second preferred embodiment of the three-phase LLC transformer current sharing circuit of this utility model; Figure 4This is a circuit diagram of the third preferred embodiment of the three-phase LLC transformer current sharing circuit of this utility model; Figure 5 yes Figure 2 The diagram shows the current sharing circuit of a three-phase LLC transformer. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] Figure 1 This is a schematic block diagram of a preferred embodiment of the current sharing circuit of a three-phase LLC transformer according to this utility model. Figure 1 As shown, the current-sharing circuit of the three-phase LLC transformer of this utility model includes a transformer module, a primary resonant module 100 connected to the primary side of the transformer module, and a rectifier module 200 connected in parallel to the secondary side of the transformer module. The transformer module includes a first transformer T1, a second transformer T2, and a third transformer T3. The first transformer T1 includes a first secondary winding T1_1 and a second secondary winding T1_2. The second transformer T2 includes a third secondary winding T2_1 and a fourth secondary winding T2_2. The third transformer T3 includes a fifth secondary winding T3_1 and a sixth secondary winding T3_2. The rectifier module 200 includes a first rectifier unit 210 and a second rectifier unit 220. The first end of any one of the first secondary winding T1_1, the third secondary winding T2_1, and the fifth secondary winding T3_1 is connected to the second rectifier unit 220, and the first ends of the remaining windings of the first secondary winding T1_1, the third secondary winding T2_1, and the fifth secondary winding T3_1 are connected to the second rectifier unit 220; the first end of any one of the second secondary winding T1_2, the fourth secondary winding T2_2, and the sixth secondary winding T3_2 is connected to the first rectifier unit 210, and the first ends of the remaining windings of the second secondary winding T1_2, the fourth secondary winding T2_2, and the sixth secondary winding T3_2 are connected to the second rectifier unit 220.

[0017] The current-sharing circuit of the three-phase LLC transformer of this utility model is implemented in which the first end of any one of the first, third, and fifth secondary windings is connected to the second rectifier unit, and the first ends of the remaining windings of the first, third, and fifth secondary windings are connected to the first rectifier unit; the first end of any one of the second, fourth, and sixth secondary windings is connected to the first rectifier unit, and the first ends of the remaining windings of the second, fourth, and sixth secondary windings are connected to the second rectifier unit; by adjusting the connection method of the transformer's secondary windings, current sharing between the two secondary windings of the transformer is achieved, thereby preventing the phenomenon of uneven current sharing between the two secondary windings of the transformer caused by the self-inductance asymmetry of the transformer's secondary windings.

[0018] In a preferred embodiment of this utility model, the primary-side resonant module 100 may include a first switching network, a second switching network, a third switching network, a first resonant unit, a second resonant unit, and a third resonant unit; the first ends of the first switching network, the second switching network, and the third switching network are respectively connected to the positive input terminal, and the second ends are respectively connected to the negative input terminal; the output end of the first switching network is connected to the first end of the primary winding of the first transformer T1 via the first resonant unit; the output end of the second switching network is connected to the first end of the primary winding of the second transformer T2 via the second resonant unit; the output end of the third switching network is connected to the first end of the primary winding of the third transformer T3 via the third resonant unit; the second end of the primary winding of the first transformer T1 is connected to the second end of the primary winding of the second transformer T2 and the second end of the primary winding of the third transformer T3. The first switching network, the second switching network, and the third switching network may each include a half-bridge and a full-bridge of switching transistors. The first resonant unit, the second resonant unit, and the third resonant unit each include a resonant capacitor and a resonant inductor connected in series.

[0019] In this invention, the first switch network, the second switch network, and the third switch network include, but are not limited to, bridge circuits, such as three-level full-bridge or phase-shifted full-bridge. The switching transistors used include, but are not limited to, Si MOS, IGBT, GaN MOS, and SiC MOS.

[0020] In a preferred embodiment of the present invention, the first rectifier unit 210 and the second rectifier unit 220 may include a switching transistor rectifier unit or a diode rectifier unit.

[0021] Figure 2 This is a circuit diagram of a first preferred embodiment of the three-phase LLC transformer current sharing circuit of this utility model. Combined with... Figures 1-2 As shown, the current-sharing circuit of the three-phase LLC transformer of this utility model includes a transformer module, a primary resonant module 100 connected to the primary side of the transformer module, and a rectifier module 200 connected in parallel to the secondary side of the transformer module. The transformer module includes a first transformer T1, a second transformer T2, and a third transformer T3. The first transformer T1 includes a first secondary winding T1_1 and a second secondary winding T1_2. The second transformer T2 includes a third secondary winding T2_1 and a fourth secondary winding T2_2. The third transformer T3 includes a fifth secondary winding T3_1 and a sixth secondary winding T3_2. The rectifier module 200 includes a first rectifier unit 210 and a second rectifier unit 220.

[0022] like Figure 2 As shown, the first end of the first secondary winding T1_1 is connected to the first end of the second rectifier unit 220, the first end of the second secondary winding T1_2 is connected to the first end of the first rectifier unit 210, the first end of the third secondary winding T2_1 is connected to the second end of the first rectifier unit 210, the first end of the fourth secondary winding T2_2 is connected to the second end of the second rectifier unit 220, the first end of the fifth secondary winding T3_1 is connected to the third end of the first rectifier unit 210, and the first end of the sixth secondary winding T3_2 is connected to the third end of the second rectifier unit 220; the second end of the first secondary winding T1_1 is connected to the second ends of the fourth secondary winding T2_2 and the sixth secondary winding T3_2; the second end of the second secondary winding T1_2 is connected to the second ends of the third secondary winding T2_1 and the fifth secondary winding T3_1.

[0023] like Figure 2 As shown, the first rectifier unit 210 includes diodes D1, D2, D3, D4, D5, and D6; the anode of diode D1 and the cathode of diode D2 are connected to the first terminal of the first rectifier unit 210, the anode of diode D3 and the cathode of diode D4 are connected to the second terminal of the first rectifier unit 210, and the anode of diode D5 and the cathode of diode D6 are connected to the third terminal of the first rectifier unit 210; the cathodes of diodes D1, D3, and D5 are connected to the positive output terminal; and the cathodes of diodes D2, D4, and D6 are connected to the negative output terminal. Further as... Figure 2 As shown, the first rectifier unit 210 further includes a first output capacitor and a first output resistor; the first output capacitor and the first output resistor are connected in series between the output positive terminal and the output negative terminal.

[0024] The second rectifier unit 220 includes diodes D7, D8, D9, D10, D11, and D12. The anode of diode D7 and the cathode of diode D8 are connected to the first terminal of the second rectifier unit 220; the anode of diode D9 and the cathode of diode D10 are connected to the second terminal of the second rectifier unit 220; and the anode of diode D11 and the cathode of diode D12 are connected to the third terminal of the second rectifier unit 220. The cathodes of diodes D7, D9, and D11 are connected to the positive output terminal; and the cathodes of diodes D8, D10, and D12 are connected to the negative output terminal. Further as... Figure 2 As shown, the second rectifier unit 220 further includes a second output capacitor and a second output resistor; the second output capacitor and the second output resistor are connected in series between the output positive terminal and the output negative terminal.

[0025] Further as Figure 2 As shown, the primary-side resonant module 100 includes a first switching network, a second switching network, a third switching network, a first resonant unit, a second resonant unit, and a third resonant unit. The first terminals of the first, second, and third switching networks are respectively connected to the positive input terminal, and their second terminals are respectively connected to the negative input terminal. The output terminal of the first switching network is connected to the first terminal of the primary winding of the first transformer T1 via the first resonant unit; the output terminal of the second switching network is connected to the first terminal of the primary winding of the second transformer T2 via the second resonant unit; the output terminal of the third switching network is connected to the first terminal of the primary winding of the third transformer T3 via the third resonant unit; the second terminal of the primary winding of the first transformer T1 is connected to the second terminal of the primary winding of the second transformer T2 and the second terminal of the primary winding of the third transformer T3. The first, second, and third switching networks each include a switching transistor half-bridge; the first, second, and third resonant units each include a resonant capacitor and a resonant inductor connected in series.

[0026] Figure 3 This is a circuit diagram of a second preferred embodiment of the current sharing circuit of the three-phase LLC transformer of this utility model. Figure 3 and Figure 2 The difference is that, Figure 2 The connection method of the first secondary winding T1_1 and the second secondary winding T1_2 of the first transformer T1 was adjusted. Figure 3 The connection methods of the third secondary winding T2_1 and the fourth secondary winding T2_2 of the second transformer T2 have been adjusted, so only the differences are explained below.

[0027] like Figure 3 As shown, the first end of the first secondary winding T1_1 is connected to the first end of the first rectifier unit 210; the first end of the second secondary winding T1_2 is connected to the second end of the second rectifier unit 220; the first end of the third secondary winding T2_1 is connected to the second end of the second rectifier unit 220; the first end of the fourth secondary winding T2_2 is connected to the second end of the first rectifier unit 210; the first end of the fifth secondary winding T3_1 is connected to the third end of the first rectifier unit 210; and the first end of the sixth secondary winding T3_2 is connected to the third end of the second rectifier unit 220. The second end of the first secondary winding T1_1 is connected to the second end of the fourth secondary winding T2_2 and the second end of the fifth secondary winding T3_1. The second end of the second secondary winding T1_2 is connected to the second end of the third secondary winding T2_1 and the second end of the sixth secondary winding T3_2.

[0028] Figure 4 This is a circuit diagram of the third preferred embodiment of the current sharing circuit of the three-phase LLC transformer of this utility model. Figure 4 and Figure 2 The difference is that, Figure 2 The connection method of the first secondary winding T1_1 and the second secondary winding T1_2 of the first transformer T1 was adjusted. Figure 4 The connection methods of the fifth secondary winding T3_1 and the sixth secondary winding T3_2 of the third transformer T3 have been adjusted, so only the differences are explained below.

[0029] like Figure 4 As shown, the first end of the first secondary winding T1_1 is connected to the first end of the first rectifier unit 210; the first end of the second secondary winding T1_2 is connected to the second end of the second rectifier unit 220; the first end of the third secondary winding T2_1 is connected to the second end of the first rectifier unit 210; the first end of the fourth secondary winding T2_2 is connected to the second end of the second rectifier unit 220; the first end of the fifth secondary winding T3_1 is connected to the third end of the second rectifier unit 220; and the first end of the sixth secondary winding T3_2 is connected to the third end of the first rectifier unit 210. The second end of the first secondary winding T1_1 is connected to the second end of the third secondary winding T2_1 and the second end of the sixth secondary winding T3_2. The second end of the second secondary winding T1_2 is connected to the second end of the fourth secondary winding T2_2 and the second end of the fifth secondary winding T3_1.

[0030] Figure 5 yes Figure 2 The diagram below shows the current sharing circuit of a three-phase LLC transformer. Figure 2 and 5 The principle of the current sharing circuit of the three-phase LLC transformer of this utility model is explained as follows. The current sharing circuit of the existing three-phase LLC transformer can achieve good balance of the three-phase current without the need for additional control by connecting the primary winding in series and the secondary winding in parallel. However, when the self-inductance of the two windings on the secondary side is asymmetrical (due to the winding method, the self-inductance of one of the secondary windings is too large), it will cause the two windings on the secondary side of the transformer to be unevenly current-sharing.

[0031] In principle, analyzing the relationship between transformer turns ratio and voltage, different turns ratios result in different voltages in the output windings. Connecting voltage sources of different voltages in parallel requires an additional internal circulating current to achieve voltage equality. The magnitude of this circulating current is related to the series inductance; that is, the larger the leakage inductance of the coil, the better the suppression of current unevenness caused by different turns ratios.

[0032] by Figure 2 For example, when the transformer winding method is fixed and the coupling coefficients of the two secondary windings are not equal, the currents of the two secondary windings will be not equal. In the existing technology, if the self-inductance of the first secondary winding T1_1 is greater than that of the second secondary winding T1_2, the self-inductance of the third secondary winding T2_1 is greater than that of the fourth secondary winding T2_2, the self-inductance of the fifth secondary winding T3_1 is greater than that of the sixth secondary winding T3_2, the self-inductances of the first secondary winding T1_1, the third secondary winding T2_1, and the fifth secondary winding T3_1 are equivalent, and the self-inductances of the second secondary winding T1_2, the fourth secondary winding T2_2, and the sixth secondary winding T3_2 are equivalent, then the current of the first secondary winding T1_1 is less than the current of the second secondary winding T1_2, the current of the third secondary winding T2_1 is less than the current of the fourth secondary winding T2_2, and the current of the fifth secondary winding T3_1 is less than the current of the sixth secondary winding T3_2.

[0033] At this time, adopt Figure 2 When connected in this way, the current is as follows Figure 5 As shown. Since the self-inductance of the second secondary winding T1_2, the fourth secondary winding T2_2, and the sixth secondary winding T3_2 are equivalent, the self-inductance of the current I2 of the second secondary winding T1_2 and the current I3 of the sixth secondary winding T3_2 are also equivalent, and their effective values ​​are the same. Furthermore, since the first secondary winding T1_1, the fourth secondary winding T2_2, and the sixth secondary winding T3_2 are connected, the phase difference between the current I1 of the first secondary winding T1_1, the current I2 of the second secondary winding T1_2, and the current I3 of the sixth secondary winding T3_2 is 120 degrees.

[0034] Assume I2=I3=I,

[0035] Therefore, the effective value of the current I1 is also I. The current I1 of the first secondary winding T1_1, the current I2 of the second secondary winding T1_2 and the current I3 of the sixth secondary winding T3_2 are 120 degrees out of phase and have the same effective value, so current sharing can be achieved.

[0036] against Figures 3-4 The embodiments shown are based on similar principles and will not be described in detail here.

[0037] Although this utility model has been described through specific embodiments, those skilled in the art should understand that various modifications and equivalent substitutions can be made to this utility model without departing from its scope. Furthermore, various modifications can be made to this utility model for specific situations or materials without departing from its scope. Therefore, this utility model is not limited to the specific embodiments disclosed, but should include all embodiments falling within the scope of the claims of this utility model.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A current sharing circuit for a three-phase LLC transformer, characterized in that, It includes a transformer module, a primary resonant module connected to the primary side of the transformer module, and a rectifier module connected in parallel to the secondary side of the transformer module. The transformer module includes a first transformer, a second transformer, and a third transformer. The first transformer includes a first secondary winding and a second secondary winding. The second transformer includes a third secondary winding and a fourth secondary winding. The third transformer includes a fifth secondary winding and a sixth secondary winding. The rectifier module includes a first rectifier unit and a second rectifier unit; The first end of any one of the first secondary winding, the third secondary winding, and the fifth secondary winding is connected to the second rectifier unit, and the first end of the remaining windings of the first secondary winding, the third secondary winding, and the fifth secondary winding is connected to the first rectifier unit. The first end of any one of the second secondary winding, the fourth secondary winding, and the sixth secondary winding is connected to the first rectifier unit, and the first end of the remaining windings of the second secondary winding, the fourth secondary winding, and the sixth secondary winding is connected to the second rectifier unit.

2. The three-phase LLC transformer current sharing circuit according to claim 1, characterized in that, The first end of the first secondary winding is connected to the first end of the second rectifier unit, the first end of the second secondary winding is connected to the first end of the first rectifier unit, the first end of the third secondary winding is connected to the second end of the first rectifier unit, the first end of the fourth secondary winding is connected to the second end of the second rectifier unit, the first end of the fifth secondary winding is connected to the third end of the first rectifier unit, and the first end of the sixth secondary winding is connected to the third end of the second rectifier unit. The second end of the first secondary winding is connected to the second end of the fourth secondary winding and the second end of the sixth secondary winding; The second end of the second secondary winding is connected to the second end of the third secondary winding and the second end of the fifth secondary winding.

3. The three-phase LLC transformer current sharing circuit according to claim 1, characterized in that, The first end of the first secondary winding is connected to the first end of the first rectifier unit, the first end of the second secondary winding is connected to the second end of the second rectifier unit, the first end of the third secondary winding is connected to the second end of the second rectifier unit, the first end of the fourth secondary winding is connected to the second end of the first rectifier unit, the first end of the fifth secondary winding is connected to the third end of the first rectifier unit, and the first end of the sixth secondary winding is connected to the third end of the second rectifier unit. The second end of the first secondary winding is connected to the second end of the fourth secondary winding and the second end of the fifth secondary winding; The second end of the second secondary winding is connected to the second end of the third secondary winding and the second end of the sixth secondary winding.

4. The three-phase LLC transformer current sharing circuit according to claim 1, characterized in that, The first end of the first secondary winding is connected to the first end of the first rectifier unit, the first end of the second secondary winding is connected to the second end of the second rectifier unit, the first end of the third secondary winding is connected to the second end of the first rectifier unit, the first end of the fourth secondary winding is connected to the second end of the second rectifier unit, the first end of the fifth secondary winding is connected to the third end of the second rectifier unit, and the first end of the sixth secondary winding is connected to the third end of the first rectifier unit. The second end of the first secondary winding is connected to the second end of the third secondary winding and the second end of the sixth secondary winding; The second end of the second secondary winding is connected to the second end of the fourth secondary winding and the second end of the fifth secondary winding.

5. The three-phase LLC transformer current sharing circuit according to any one of claims 1 to 4, characterized in that, The first rectifier unit includes a first diode, a second diode, a third diode, a fourth diode, a fifth diode, and a sixth diode; The anode of the first diode and the cathode of the second diode are connected to the first terminal of the first rectifier unit; the anode of the third diode and the cathode of the fourth diode are connected to the second terminal of the first rectifier unit; and the anode of the fifth diode and the cathode of the sixth diode are connected to the third terminal of the first rectifier unit. The cathodes of the first diode, the third diode, and the fifth diode are connected to the positive output terminal; The cathodes of the second diode, the fourth diode, and the sixth diode are connected to the negative output terminal.

6. The three-phase LLC transformer current sharing circuit according to claim 5, characterized in that, The first rectifier unit further includes a first output capacitor and a first output resistor; The first output capacitor and the first output resistor are connected in series between the positive output terminal and the negative output terminal.

7. The three-phase LLC transformer current sharing circuit according to any one of claims 1 to 4, characterized in that, The second rectifier unit includes a seventh diode, an eighth diode, a ninth diode, a tenth diode, an eleventh diode, and a twelfth diode; The anode of the seventh diode and the cathode of the eighth diode are connected to the first terminal of the second rectifier unit; the anode of the ninth diode and the cathode of the tenth diode are connected to the second terminal of the second rectifier unit; and the anode of the eleventh diode and the cathode of the twelfth diode are connected to the third terminal of the second rectifier unit. The cathodes of the seventh diode, the ninth diode, and the eleventh diode are connected to the positive output terminal. The cathodes of the eighth diode, the tenth diode, and the twelfth diode are connected to the negative output terminal.

8. The three-phase LLC transformer current sharing circuit according to claim 7, characterized in that, The second rectifier unit further includes a second output capacitor and a second output resistor; The second output capacitor and the second output resistor are connected in series between the positive output terminal and the negative output terminal.

9. The three-phase LLC transformer current sharing circuit according to any one of claims 1 to 4, characterized in that, The primary-side resonant module includes a first switching network, a second switching network, a third switching network, a first resonant unit, a second resonant unit, and a third resonant unit; The first terminal of the first switch network, the second switch network, and the third switch network are respectively connected to the positive input terminal, and the second terminal is respectively connected to the negative input terminal. The output terminal of the first switching network is connected to the first terminal of the primary winding of the first transformer via the first resonant unit; The output of the second switching network is connected to the first end of the primary winding of the second transformer via the second resonant unit; The output terminal of the third switching network is connected to the first terminal of the primary winding of the third transformer via the third resonant unit; The second end of the primary winding of the first transformer is connected to the second end of the primary winding of the second transformer and the second end of the primary winding of the third transformer.

10. The three-phase LLC transformer current sharing circuit according to claim 9, characterized in that, The first switch network, the second switch network, and the third switch network each include a switch transistor half-bridge; The first resonant unit, the second resonant unit, and the third resonant unit each include a resonant capacitor and a resonant inductor connected in series with each other.

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