Star-connected five-phase power converter and charging equipment

Abstract

The utility model discloses a star-connected five-phase power converter and charging equipment, first input ends of primary sides of transformers in a first five-phase transformer are respectively connected with output ends of corresponding first five-phase chopper circuits through corresponding resonance circuits, and second input ends of the primary sides of the transformers in the first five-phase transformer are mutually connected; the second output ends of the secondary sides of the transformers in the first five-phase transformer are mutually connected, and the first output ends of the secondary sides of the transformers in the first five-phase transformer are connected with the input ends of the corresponding first five-phase rectifying circuits; the output end of the first five-phase rectification circuit is connected with the input end of the filter circuit, and the output end of the filter circuit is connected with a load, so that a technology of connecting a plurality of power tubes in parallel is not used, and the problem of non-uniform current failure caused by parallel connection can be reduced; according to the utility model, the generation of ripple voltage and ripple current can be greatly reduced through the star-connected five-phase power converter.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and particularly to a star-connected five-phase power converter and a charging device. Background Art

[0002] In the application of new energy charging piles, the core component of high-power DC charging piles is the power converter. The common DC-DC topologies in power converters mainly include half-bridge, full-bridge, three-phase and other structures; the half-bridge, full-bridge, three-phase and other structures are further divided into two-level, three-level, primary series / parallel, secondary series / parallel and other methods according to different design ideas.

[0003] With the market's requirement for increasing the output power of power converters and the requirement for the quality of output voltage ripple and current ripple, the general solution is to solve it by adding an output filter. This solution cannot meet the market's requirements for high power density and low cost. However, in the design of power converters, reducing ripple, lowering costs, and improving reliability are directions that need continuous optimization. Utility Model Content

[0004] The main purpose of this application is to provide a star-connected five-phase power converter and a charging device, aiming to solve the technical problem that the power converter in the existing technology needs further optimization in reducing ripple, lowering costs, and improving reliability.

[0005] To achieve the above object, this application provides a star-connected five-phase power converter, including: a filter circuit, a first five-phase chopper circuit, a resonant circuit, a first five-phase transformer, and a first five-phase rectifier circuit; the first input terminals of the primaries of the transformers in the first five-phase transformer are respectively connected to the output terminals of the corresponding first five-phase chopper circuits through the corresponding resonant circuits, and the second input terminals of the primaries of the transformers in the first five-phase transformer are connected to each other; the second output terminals of the secondaries of the transformers in the first five-phase transformer are connected to each other, and the first output terminals of the secondaries of the transformers in the first five-phase transformer are connected to the input terminals of the corresponding first five-phase rectifier circuits; the output terminal of the first five-phase rectifier circuit is connected to the input terminal of the filter circuit, and the output terminal of the filter circuit is connected to the load.

[0006] Optionally, the first five-phase chopper circuit includes a three-level five-phase chopper circuit or a two-level five-phase chopper circuit.

[0007] Optionally, the two-level five-phase chopper circuit has a first common input terminal, a second common input terminal, and five output terminals; wherein, the two-level five-phase chopper circuit includes five parallel-connected first switch branches, and the first switch branch includes a first switch tube and a second switch tube; the first ends of the first switch tubes are connected to each other to form the first common input terminal of the two-level five-phase chopper circuit, and the second ends of the second switch tubes are connected to each other to form the second common input terminal of the two-level five-phase chopper circuit; in the same first switch branch, the second end of the first switch tube is connected to the first input terminal of the second switch tube to form an output terminal of the two-level five-phase chopper circuit, and the control terminals of the first switch tube and the second switch tube are both connected to the control circuit.

[0008] Optionally, the three-level five-phase chopper circuit has a first common input terminal, a second common input terminal, a third common input terminal, and five output terminals; wherein, the three-level five-phase chopper circuit includes five parallel-connected second switch branches, and the second switch branch includes a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a first power semiconductor device, and a second power semiconductor device; wherein, in the same second switch branch, the third switch tube, the fourth switch tube, the fifth switch tube, and the sixth switch tube are connected in series in sequence, the first ends of the first switch tubes are connected to each other to form the first common input terminal of the three-level five-phase chopper circuit, and the second ends of the sixth switch tubes are connected to each other to form the second common input terminal of the three-level five-phase chopper circuit; the second pole of the first power semiconductor device is connected to the first pole of the second power semiconductor device, the first pole of the first power semiconductor device is connected in series between the third switch tube and the fourth switch tube, the second pole of the second power semiconductor device is connected in series between the fifth switch tube and the sixth switch tube, and the connection of the second pole of the first power semiconductor device and the first pole of the second power semiconductor device forms the third common input terminal of the three-level five-phase chopper circuit; the connection of the fourth switch tube and the fifth switch tube forms an output terminal of the three-level five-phase chopper circuit, and the control terminals of the third switch tube, the fourth switch tube, the fifth switch tube, and the sixth switch tube are all connected to the control circuit.

[0009] Optionally, the first five-phase transformer includes a first transformer to a fifth transformer. The primary sides of the first transformer to the fifth transformer each have a first input terminal and a second input terminal, and the secondary sides of the first transformer to the fifth transformer each have a first output terminal and a second output terminal. The first input terminals of the first transformer to the fifth transformer in the first five-phase transformer are respectively connected to the output terminals of the first five-phase chopper circuit through a resonance circuit, and the second input terminals of the first transformer to the fifth transformer in the first five-phase transformer are connected to each other. The second output terminals of the first five-phase transformer are connected to each other, and the first output terminal of the first five-phase transformer is connected to the input terminal of the first five-phase rectifier circuit. Or, the second input terminals of the first transformer to the fifth transformer in the first five-phase transformer are connected, the second output terminals of the first transformer to the fifth transformer in the first five-phase transformer are connected to the first output terminal of the next transformer, and the first output terminal of the first five-phase transformer is connected to the input terminal of the first five-phase rectifier circuit.

[0010] Optionally, the resonance circuit includes a plurality of series / parallel inductance circuits and capacitance circuits.

[0011] Optionally, the first five-phase rectifier circuit has five input terminals, a first common output terminal, and a second common output terminal. The first five-phase rectifier circuit includes: five parallel rectifier branches, and each rectifier branch includes a first power semiconductor device and a second power semiconductor device. The first ends of the first power semiconductor devices in each parallel rectifier branch are connected to form the first common output terminal, and the second ends of the second power semiconductor devices in each parallel rectifier branch are connected to form the second common output terminal. The first end of the first power semiconductor device is connected to the first common output terminal of the first five-phase rectifier circuit, the second end of the second power semiconductor device is connected to the second common output terminal of the first five-phase rectifier circuit, and the first power semiconductor device and the second power semiconductor device in each rectifier branch are connected to form an input terminal of the first five-phase rectifier circuit.

[0012] Optionally, the filter circuit includes: a differential-mode inductor, the first end of which is connected to the first common output terminal of the first five-phase rectifier circuit; a first filter branch, the first end of which is connected to the second end of the differential-mode inductor, and the second end of which is connected to the second common output terminal of the first five-phase rectifier circuit; a common-mode inductor, including a first winding and a second winding, the first end of the first winding and the first end of the second winding are respectively connected to the first end and the second end of the first capacitor branch; a second filter branch, the first end and the second end of which are respectively connected to the second end of the first winding of the common-mode inductor and the second end of the second winding of the common-mode inductor.

[0013] Optionally, the star-connected five-phase power converter further includes a second five-phase chopper circuit, a second five-phase transformer, and a second five-phase rectifier circuit that are adjacent to the first five-phase chopper circuit, the first five-phase transformer, and the first five-phase rectifier circuit respectively; wherein, each first five-phase chopper circuit and each second five-phase chopper circuit are connected in parallel; or the second common input terminal of the first five-phase chopper circuit is connected to the first common input terminal of the second five-phase chopper circuit; the first input terminals of the primary sides of the transformers of the first five-phase transformer are respectively connected to the output terminals of the corresponding first five-phase chopper circuits through corresponding resonant circuits, the second input terminals of the primary sides of the transformers of the first five-phase transformer are respectively connected to the first input terminals of the primary sides of the corresponding second five-phase transformers, and the second input terminals of the primary sides of the transformers of each second five-phase transformer are respectively connected to the output terminals of the corresponding second five-phase chopper circuits; the second output terminals of the secondary sides of the transformers of the first five-phase transformer are all connected to each other, and the second output terminals of the secondary sides of the transformers of the second five-phase transformer are all connected to each other; and the first output terminals of each transformer of the second five-phase transformer are connected to the input terminals of the corresponding second five-phase rectifier circuit; or, the second output terminals of the secondary sides of the transformers of the first five-phase transformer are connected to the first output terminals of the secondary sides of the next-stage transformers, and the second output terminal of the last transformer is connected to the first output terminal of the first transformer; the second output terminals of the secondary sides of the transformers of the second five-phase transformer are connected to the first output terminals of the secondary sides of the next-stage transformers, and the second output terminal of the last transformer is connected to the first output terminal of the first transformer; and the first output terminals of each transformer of the second five-phase transformer are connected to the input terminals of the corresponding second five-phase rectifier circuit; the output terminals of the first five-phase rectifier circuit and the output terminals of the second five-phase rectifier circuit are connected in parallel and are both connected to the input terminal of the filter circuit, and the output terminal of the filter circuit is connected to the load.

[0014] Optionally, the star-connected five-phase power converter further includes a plurality of input filter capacitors and a plurality of output filter capacitors; the input filter capacitors are connected in parallel between the first common input terminal and the second common input terminal of the first five-phase chopper circuit, and another input filter capacitor is connected in parallel between the first common input terminal and the second common input terminal of the second five-phase chopper circuit; the output filter capacitors are connected in parallel between the first common output terminal and the second common output terminal of the first five-phase rectifier circuit, and another output filter capacitor is connected in parallel between the first common output terminal and the second common output terminal of the second five-phase rectifier circuit.

[0015] To solve the above technical problems, an embodiment of the present application further provides a charging device, including a star-connected five-phase power converter.

[0016] To achieve the above object, the present application further provides a charging device, including a star-connected five-phase power converter.

[0017] A five-phase power converter with star connection and a charging device proposed in an embodiment of the present application. The first common input terminals and the second common input terminals of each first five-phase chopper circuit and each second five-phase chopper circuit are all connected in parallel, or the second common input terminal of the first five-phase chopper circuit and the first common input terminal of the second five-phase chopper circuit of each conversion unit are cascaded in sequence; the second input terminals of the primary sides of the transformers of the first five-phase transformer of each conversion unit are connected to the first input terminals of the primary sides of the transformers of the second five-phase transformer, and the first input terminals of the primary sides of the transformers of the first five-phase transformer are respectively connected to the output terminals of the first five-phase chopper circuit through each resonance circuit, and the second input terminals of the primary sides of the transformers of the second five-phase transformer are respectively connected to the output terminals of the second five-phase chopper circuit; the secondary sides of the transformers of the first five-phase transformer of each conversion unit and the secondary sides of the transformers of the second five-phase transformer are all connected in a pentagon or star connection, and the first output terminals of the transformers of the first five-phase transformer and the input terminals of the first five-phase rectifier circuit are respectively connected, and the first output terminals of the transformers of the second five-phase transformer and the input terminals of the second five-phase rectifier circuit are respectively connected; the first common output terminal and the second common output terminal after the parallel connection of the first five-phase rectifier circuit and the second five-phase rectifier circuit of each conversion unit are respectively connected to the first input terminal and the second input terminal of the filter circuit, and the two output terminals of the filter circuit of the present utility model are connected to the load, so that the technology of parallel connection of multiple power tubes can be not used, the problem of uneven current failure caused by parallel connection can be reduced, the star-connected five-phase power converter of the present utility model can greatly reduce the generation of ripple voltage and ripple current, the ripple voltage generated by the H bridge is reduced by more than 50%, the technology of parallel connection of multiple power tubes is not used, the problem of uneven current failure caused by parallel connection can be reduced, and topological series-parallel expansion can be carried out, and it is easy to realize a larger power converter. Description of the Drawings

[0018] Figure 1 It is a structural block diagram of a series star-connected five-phase power converter provided by an embodiment of the present application;

[0019] Figure 2 It is a structural block diagram of a parallel star-connected five-phase power converter provided by an embodiment of the present application;

[0020] Figure 3 It is a structural block diagram of a two-level star-connected five-phase power converter provided by an embodiment of the present application;

[0021] Figure 4 It is a structural block diagram of a three-level star-connected five-phase power converter provided by an embodiment of the present application;

[0022] Figure 5 It is a structural diagram of a chopper circuit of a two-level star five-phase converter provided by an embodiment of the present application;

[0023] Figure 6 The structure diagram of the three-level star-connected five-phase converter chopper circuit provided by an embodiment of the present application;

[0024] Figure 7 The structure diagram of the five-phase transformer with a star-connected primary side and a star-connected secondary side provided by an embodiment of the present application;

[0025] Figure 8 The structure diagram of the five-phase transformer with a star-connected primary side and a pentagon-connected secondary side provided by an embodiment of the present application;

[0026] Figure 9 The structure diagram of the rectifier circuit provided by an embodiment of the present application;

[0027] Figure 10 The structure diagram of the filter circuit provided by an embodiment of the present application.

[0028] The implementation, functional features and advantages of the present application will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0029] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] It should be noted that the first, second, etc. sequences in the embodiments of the present application are determined in sequence according to the flow direction of the power supply current.

[0031] Figure 1 The structure block diagram of the series star-connected five-phase power converter provided by an embodiment of the present application, Figure 2 The structure block diagram of the parallel star-connected five-phase power converter provided by an embodiment of the present application, Figure 3 The structure block diagram of the two-level star-connected five-phase power converter provided by an embodiment of the present application, Figure 4 The structure block diagram of the star-connected three-level star-connected five-phase power converter provided by an embodiment of the present application, referring to Figures 1 - 4 , the star-connected five-phase power converter may include: a filter circuit 600, a first five-phase chopper circuit 201, a resonant circuit 202, a first five-phase transformer 203, and a first five-phase rectifier circuit 204; the first input ends of the primaries of the transformers in the first five-phase transformer 203 are respectively connected to the output ends of the corresponding first five-phase chopper circuits 201 through the corresponding resonant circuits 202, and the second input ends of the primaries of the transformers in the first five-phase transformer 203 are connected to each other; the second output ends of the secondaries of the transformers in the first five-phase transformer 203 are connected to each other, and the first output ends of the secondaries of the transformers in the first five-phase transformer 203 and the input ends of the corresponding first five-phase rectifier circuits 204 are connected; the output end of the first five-phase rectifier circuit 204 is connected to the input end of the filter circuit 600, and the output end of the filter circuit 600 is connected to the load.

[0032] It should be understood that all the number of levels input by the multi-level five-phase chopper circuit are within the scope included in the embodiments of the present invention, and no specific limitation is made here.

[0033] In the embodiments of the present application, the first five-phase chopper circuit 201 may include a three-level five-phase chopper circuit or a two-level five-phase chopper circuit. It should be noted that the first five-phase chopper circuit 201 is either all three-level five-phase chopper circuits or all two-level five-phase chopper circuits.

[0034] Figure 5 The structural diagram of the two-level star-connected five-phase converter chopper circuit provided by an embodiment of the present application is shown in Figure 5 As shown, in the embodiments of the present application, the two-level five-phase chopper circuit has a first common input terminal, a second common input terminal, and five output terminals; wherein, the two-level five-phase chopper circuit includes five parallel first switch branches, and the first switch branch includes a first switch tube Q1 and a second switch tube Q2; the first ends of the first switch tubes Q1 are connected to each other to form the first common input terminal of the two-level five-phase chopper circuit, and the second ends of the second switch tubes Q2 are connected to each other to form the second common input terminal of the two-level five-phase chopper circuit; in the same first switch branch, the second end of the first switch tube Q1 is connected to the first input terminal of the second switch tube Q2 to form an output terminal of the two-level five-phase chopper circuit, and the control terminals of the first switch tube Q1 and the second switch tube Q2 are both connected to the control circuit.

[0035] It should be noted that the control circuit has nothing to do with the technical problems to be solved by the present invention, so it is not shown in the figure.

[0036] Specifically, the first switch tube Q1 and the second switch tube Q2 may be one of a triode, Si MOS, SiC MOS, and IGBT.

[0037] Exemplarily, the five-phase power converter based on the two-level star connection is shown in Figure 5 As shown, among them, five parallel first switch branches form five-phase bridge arms, and the control timings between every two adjacent phase bridge arms differ by 72°.

[0038] Figure 6 The structural diagram of the three-level star-connected five-phase converter chopper circuit provided by an embodiment of the present application is shown in Figure 6As shown, in the embodiment of the present application, the three-level five-phase chopper circuit has a first common input terminal, a second common input terminal, a third common input terminal, and five output terminals; among them, the three-level five-phase chopper circuit includes five parallel second switch branches, and the second switch branch includes a third switch tube Q3, a fourth switch tube Q4, a fifth switch tube Q5, and a sixth switch tube Q6, as well as a first power semiconductor device D1 and a second power semiconductor device D2; among them, in the same second switch branch, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, and the sixth switch tube Q6 are connected in series in sequence. The first ends of each third switch tube are connected to each other to form the first common input terminal of the three-level five-phase chopper circuit, and the second ends of each sixth switch tube Q6 are connected to each other to form the second common input terminal of the three-level five-phase chopper circuit; the second pole of the first power semiconductor device D1 is connected to the first pole of the second power semiconductor device. The first pole of the first power semiconductor device D1 is connected in series between the third switch tube Q3 and the fourth switch tube Q4, and the second pole of the second power semiconductor device D2 is connected in series between the fifth switch tube Q5 and the sixth switch tube Q6. The second pole of the first power semiconductor device D1 and the first pole of the second power semiconductor device D2 are connected to form the third common input terminal of the three-level five-phase chopper circuit; the fourth switch tube Q4 and the fifth switch tube Q5 are connected to form the output terminal of the three-level five-phase chopper circuit, and the control terminals of the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, and the sixth switch tube Q6 are all connected to the control circuit.

[0039] It should be noted that the series connection of the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, and the sixth switch tube Q6 in sequence means that the second end of the third switch tube Q3 is connected to the first end of the fourth switch tube Q4, the second end of the fourth switch tube Q4 is connected to the first end of the fifth switch tube Q5, and the second end of the fifth switch tube Q5 is connected to the first end of the sixth switch tube Q6. Figure 6Among them, the third switching transistor Q3 in the first second switching branch is Q3-1, the third switching transistor Q3 in the second second switching branch is Q3-2, the third switching transistor Q3 in the third second switching branch is Q3-3, the third switching transistor Q3 in the fourth second switching branch is Q3-4, and the third switching transistor Q3 in the fifth second switching branch is Q3-5. The same applies to the other fourth switching transistor Q4, fifth switching transistor Q5, and sixth switching transistor Q6, which will not be elaborated here. Similarly, the first power semiconductor device in the first second switching branch is D1-1, the first power semiconductor device in the second second switching branch is D1-2, the first power semiconductor device in the third second switching branch is D1-3, the first power semiconductor device in the fourth second switching branch is D1-4, and the first power semiconductor device in the fifth second switching branch is D1-5. The same applies to the other first power semiconductor devices and second power semiconductor devices, which will not be elaborated here.

[0040] Exemplarily, a five-phase power converter based on a three-level star connection is as Figure 6 shown, where five parallel second switching branches form the fifth phase arm, and the control timing between every two adjacent phase arms differs by 72°.

[0041] Exemplarily, the third switching transistor Q3, fourth switching transistor Q4, fifth switching transistor Q5, and sixth switching transistor Q6 can be one or more of an NPN-type triode, PNP-type triode, Si MOS (silicon MOSFET), SiC MOS (silicon carbide MOSFET), or IGBT insulated gate bipolar transistor. The first power semiconductor device D1 and the second power semiconductor device D2 can be one or more of a diode, triode, SiMOS, SiCMOS, or IGBT. In addition, it should be noted that when the power semiconductor device is a diode, the cathode of the diode is the first pole, and the anode of the diode is the second pole.

[0042] In the embodiment of the present application, the first five-phase transformer 203 may include a first transformer T1 to a fifth transformer T5. The primary sides of the first transformer T1 to the fifth transformer T5 each have a first input terminal and a second input terminal, and the secondary sides of the first transformer T1 to the fifth transformer T5 each have a first output terminal and a second output terminal. The respective first input terminals of the first transformer T1 to the fifth transformer T5 in the first five-phase transformer 203 are each connected to the respective output terminals of the first five-phase chopper circuit 201 through a resonance circuit 202, and the respective second input terminals of the first transformer T1 to the fifth transformer T5 in the first five-phase transformer 203 are connected to each other. The respective second output terminals of the first transformer T1 to the fifth transformer T5 in the first five-phase transformer 203 are connected to each other.

[0043] Figure 7 The structure diagram of a five-phase transformer with a star-connected primary side and a star-connected secondary side provided by an embodiment of the present application is as follows Figure 7 shown. Specifically, when the primary sides of the first transformer T1 to the fifth transformer T5 are star-connected and the secondary sides are star-connected, the second input terminals of the first transformer T1 to the fifth transformer T5 are connected to each other, and the second output terminals of the first transformer T1 to the fifth transformer T5 are connected to each other.

[0044] Figure 8 The structure diagram of a five-phase transformer with a star-connected primary side and a pentagon-connected secondary side provided by an embodiment of the present application is as follows Figure 8 shown. When the primary sides of the first transformer T1 to the fifth transformer T5 are star-connected and the secondary sides are pentagon-connected, the second input terminals of the first transformer T1 to the fifth transformer T5 are connected to each other, and the second output terminals of the first transformer T1 to the fifth transformer T5 are connected to the first output terminal of the next transformer, and the second output terminal of the last transformer is connected to the first output terminal of the first transformer.

[0045] Referring to Figure 3 and Figure 4 , in the embodiment of the present application, the resonant circuit 202 may include a plurality of inductive circuits and capacitive circuits connected in series / parallel. Specifically, the resonant circuit 202 includes at least one inductor and one capacitor; in addition to the LC circuit composed of one inductor and one capacitor in the resonant circuit, there is also a resonant circuit composed of one inductor and two capacitors, a resonant circuit composed of two inductors and capacitors; when there are a plurality of inductors and a plurality of capacitors forming a resonant circuit, the inductors and capacitors can be combined in series and parallel manners; Figure 3 and Figure 4 The resonant circuits 202 shown are both composed of an inductor and a capacitor connected in series.

[0046] In the embodiment of the present application, the first five-phase rectifier circuit 204 has five input terminals, a first common output terminal and a second common output terminal; the first five-phase rectifier circuit 204 may include five parallel rectifier branches, and each rectifier branch includes a third power semiconductor device D3 and a fourth power semiconductor device D4; the first ends of the third power semiconductor devices D3 in each parallel rectifier branch are connected to form the first common output terminal, and the second ends of the fourth power semiconductor devices D4 in each parallel rectifier branch are connected to form the second common output terminal; the first end of the third power semiconductor device D3 is connected to the first common output terminal of the first five-phase rectifier circuit 204, the second end of the fourth power semiconductor device D4 is connected to the second common output terminal of the first five-phase rectifier circuit 204, and the third power semiconductor devices D3 and the fourth power semiconductor devices D4 in each rectifier branch are connected to form an input terminal of the first five-phase rectifier circuit 204.

[0047] In the figure, the third power semiconductor device in the first rectifier branch is D3-1, the third power semiconductor device in the second rectifier branch is D3-2, the third power semiconductor device in the third rectifier branch is D3-3, the third power semiconductor device in the fourth rectifier branch is D3-4, and the third power semiconductor device in the fifth rectifier branch is D3-5. The fourth power semiconductor device is similar and will not be elaborated here.

[0048] Figure 9 This is the structural diagram of the rectifier circuit provided by an embodiment of the present application. Refer to Figure 9 , where the third power semiconductor device D3 to the fourth power semiconductor device D4 can be one of a diode, a triode, a SiMOS, a SiCMOS, and an IGBT. Specifically, when the power semiconductor device is a diode, the cathode of the diode is the first pole, and the anode of the diode is the second pole.

[0049] In an embodiment of the present application, the star-connected five-phase power converter may further include a second five-phase chopper circuit 301, a second five-phase transformer 303, and a second five-phase rectifier circuit 304 that are adjacent to the first five-phase chopper circuit 201, the first five-phase transformer 203, and the first five-phase rectifier circuit 204, respectively; wherein, each of the first five-phase chopper circuits 201 and each of the second five-phase chopper circuits 301 are connected in parallel; or the second common input terminal of the first five-phase chopper circuit 201 is connected to the first common input terminal of the second five-phase chopper circuit 301; the first input terminals of the primary windings of each transformer of the first five-phase transformer 203 are respectively connected to the output terminals of the corresponding first five-phase chopper circuit 201 through corresponding resonant circuits 202, the second input terminals of the primary windings of each transformer of the first five-phase transformer 203 are respectively connected to the first input terminals of the primary windings of the corresponding second five-phase transformer 303, and the second input terminals of the primary windings of each transformer of each second five-phase transformer 303 are respectively connected to the output terminals of the corresponding second five-phase chopper circuit 301; the second output terminals of the secondary windings of each transformer of the first five-phase transformer 203 are all connected to each other, and the second output terminals of the secondary windings of each transformer of the second five-phase transformer 303 are all connected to each other; and the first output terminal of each transformer of the second five-phase transformer 303 is connected to the input terminal of the corresponding second five-phase rectifier circuit 304; or, the second output terminals of the secondary windings of each transformer of the first five-phase transformer 203 are connected to the first output terminals of the secondary windings of the next-stage transformer, and the second output terminal of the last transformer is connected to the first output terminal of the first transformer; the second output terminals of the secondary windings of each transformer of the second five-phase transformer 303 are connected to the first output terminals of the secondary windings of the next-stage transformer, and the second output terminal of the last transformer is connected to the first output terminal of the first transformer; and the first output terminal of each transformer of the second five-phase transformer 303 is connected to the input terminal of the corresponding second five-phase rectifier circuit 304; the output terminals of the first five-phase rectifier circuit 204 and the output terminals of the second five-phase rectifier circuit 304 are connected in parallel and are all connected to the input terminal of the filter circuit 600, and the output terminal of the filter circuit 600 is connected to the load.

[0050] The star connection naturally provides a neutral point, which can be used for grounding to provide electrical safety, or for load balancing, helping to reduce voltage fluctuations caused by load changes, and can reduce the influence of certain specific harmonics, especially zero-sequence harmonics. The star connection allows independent control of each phase, which helps to achieve load balancing. The star connection provides a simple and effective way to provide independent power supplies for polyphase loads. Therefore, adopting a star connection method in the primary side of the star-connected five-phase power converter has the above advantages.

[0051] Taking the two-level star-connected five-phase power converter as an example for illustrative description, the two-level star-connected five-phase power converter may include five structures.

[0052] Reference Figure 1, the first structure: Each first five-phase chopper circuit 201 and each second five-phase chopper circuit 301 are connected in parallel. That is, the first common input terminals of each first five-phase chopper circuit 201 and the first common input terminals of each second five-phase chopper circuit 301 are both connected to one end of the DC input power supply, and the second common input terminals of each first five-phase chopper circuit 201 and the second common input terminals of each second five-phase chopper circuit 301 are both connected to the other end of the DC input power supply. Both the first five-phase chopper circuit 201 and the second five-phase chopper circuit 301 include multiple output terminals. In the same conversion unit, the first input terminals of the primary sides of each transformer of the first five-phase transformer 203 are respectively connected to the output terminals of the first five-phase chopper circuit 201 through a resonance circuit 202, and the second input terminals of the primary sides of each transformer of the first five-phase transformer 203 are respectively connected to the first input terminals of the primary sides of the corresponding transformers of the second five-phase transformer 303; the secondary sides of each transformer of the first five-phase transformer 203 and the secondary sides of each transformer of the second five-phase transformer 303 are both star-connected, and the first output terminals of each transformer of the first five-phase transformer 203 are respectively connected to the input terminals of the first five-phase rectifier circuit 204. The first output terminals of each transformer of the second five-phase transformer 303 are respectively connected to the input terminals of the second five-phase rectifier circuit 304.

[0053] The difference between the second structure and the first structure is that the secondary side of the transformer is connected in a pentagon connection.

[0054] Reference Figure 2 , the difference between the third structure and the first structure is that the second common input terminals of the first five-phase chopper circuits 201 and the first common input terminals of the second five-phase chopper circuits 301 of each conversion unit are cascaded in sequence.

[0055] The difference between the fourth structure and the third structure is that the secondary side of the transformer is in a pentagon connection.

[0056] Taking a three-level star-connected five-phase power converter as an example, reference Figure 4 , in this figure, the secondary side and the primary side of the transformer are both star-connected. The power supply circuit 100 has three output terminals, and both the first five-phase chopper circuit 201 and the second five-phase chopper circuit 301 have three input terminals. Among them, two input terminals in the first five-phase chopper circuit 201 or the second five-phase chopper circuit 301 are correspondingly connected to two output terminals of the power supply circuit 100, and the third input terminal of the first five-phase chopper circuit 201 or the second five-phase chopper circuit 301 is connected to the third output terminal of the power supply circuit 100.

[0057] According to the principle of the topology itself, the technical embodiment of the present application greatly reduces the generation of ripple voltage and ripple current, and the ripple voltage generated by the H-bridge is reduced by more than 50%; the technology of parallel connection of multiple power tubes is not used, which can reduce the problem of uneven current sharing failure caused by parallel connection; based on the embodiment of the application, topology-level series and parallel expansion is carried out, and it is easy to realize the design of a larger power converter.

[0058] Figure 10 The structural diagram of the filter circuit provided by an embodiment of the present application is shown in Figure 10 、 Figure 3 、 Figure 4 In the embodiment of the present application, the filter circuit 600 may include a differential-mode inductor L1, a first filter branch, a common-mode inductor L2, and a second filter branch. Among them, the first end of the differential-mode inductor L1 is connected to the first common output terminal of the five-phase rectifier circuit; the first filter branch includes: a first capacitor C1, a third capacitor C3, and a fourth capacitor C4. Among them, one end of the first capacitor C1 is connected to the second end of the differential-mode inductor L1, and the other end of the first capacitor C1 is connected to the second common output terminal of the five-phase rectifier circuit; one end of the fourth capacitor C4 is grounded, and the other end is connected to the second common output terminal of the five-phase rectifier circuit; one end of the third capacitor C3 is connected to the second end of the differential-mode inductor L1, and the other end is grounded; the common-mode inductor L2 includes a first winding and a second winding, and the first ends of the first winding and the second winding are respectively connected to the first end and the second end of the first capacitor branch; the second filter branch includes: a second capacitor C2, a fifth capacitor C5, and a sixth capacitor C6. Among them, the two ends of the second capacitor C2 are respectively connected to the second end of the first winding and the second end of the second winding of the common-mode inductor L2 in correspondence; one end of the fifth capacitor C5 is connected to the second end of the first winding of the common-mode inductor L2, and the other end is grounded; one end of the sixth capacitor C6 is connected to the second end of the second winding of the common-mode inductor L2, and the other end is grounded. It should be understood that the second ends of the first winding and the second winding of the common-mode inductor L2 are used as the two output terminals of the filter circuit 600 and are connected to the load.

[0059] Shown in Figure 1 and Figure 2 In the embodiment of the present application, the star-connected five-phase power converter further includes an input filter capacitor 800 and an output filter capacitor 900. The input filter capacitor 800 is connected in parallel between the first common input terminal and the second common input terminal of the first five-phase chopper circuit 201, and another input filter capacitor 800 is connected in parallel between the first common input terminal and the second common input terminal of the second five-phase chopper circuit 301; the output filter capacitor 900 is connected in parallel between the first common output terminal and the second common output terminal of the first five-phase rectifier circuit 204, and another output filter capacitor 900 is connected in parallel between the first common output terminal and the second common output terminal of the second five-phase rectifier circuit 304.

[0060] Based on the above embodiments, the present application further provides a charging device, including a five-phase power converter connected in a star configuration.

[0061] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A star-connected five-phase power converter, characterized in that: include: A filter circuit (600), a first five-phase chopper circuit (201), a resonant circuit (202), a first five-phase transformer (203) and a first five-phase rectifier circuit (204); The first input end of the primary side of each transformer in the first five-phase transformer (203) is connected to the output end of the corresponding first five-phase chopper circuit (201) through the corresponding resonant circuit (202), and the second input ends of the primary sides of each transformer in the first five-phase transformer (203) are connected to each other; the second output ends of the secondary sides of each transformer in the first five-phase transformer (203) are connected to each other, and the first output end of the secondary side of each transformer in the first five-phase transformer (203) is connected to the input end of the corresponding first five-phase rectifier circuit (204); The output end of the first five-phase rectifier circuit (204) is connected to the input end of the filter circuit (600), and the output end of the filter circuit (600) is connected to a load.

2. The star-connected five-phase power converter according to claim 1, characterized in that: The first five-phase chopper circuit (201) comprises a three-level five-phase chopper circuit (702) or a two-level five-phase chopper circuit (701).

3. The star-connected five-phase power converter according to claim 2, characterized in that: The two-level five-phase chopper circuit (701) has a first common input terminal, a second common input terminal and five output terminals; The two-level five-phase chopper circuit (701) comprises five first switch branches connected in parallel, and the first switch branch comprises a first switch tube and a second switch tube; The first ends of the first switch tubes are connected to each other to form a first common input end of the two-level five-phase chopper circuit (701), and the second ends of the second switch tubes are connected to each other to form a second common input end of the two-level five-phase chopper circuit (701); In the same first switch branch, the second end of the first switch tube is connected to the first input end of the second switch tube to form an output end of the two-level five-phase chopper circuit (701), and the control ends of the first switch tube and the second switch tube are both connected to a control circuit.

4. The star-connected five-phase power converter according to claim 3, characterized in that: The three-level five-phase chopper circuit (702) has a first common input terminal, a second common input terminal, a third common input terminal and five output terminals; The three-level five-phase chopper circuit (702) comprises five second switch branches connected in parallel, wherein the second switch branch comprises a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube, and a first power semiconductor device and a second power semiconductor device; Wherein, in the same second switch branch, the third switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are connected in series in sequence, the first ends of the first switch tubes are connected to each other to form a first common input end of the three-level five-phase chopper circuit (702), and the second ends of the sixth switch tubes are connected to each other to form a second common input end of the three-level five-phase chopper circuit (702); The second pole of the first power semiconductor device is connected to the first pole of the second power semiconductor device, the first pole of the first power semiconductor device is connected in series between the third switch tube and the fourth switch tube, the second pole of the second power semiconductor device is connected in series between the fifth switch tube and the sixth switch tube, and the second pole of the first power semiconductor device and the first pole of the second power semiconductor device are connected to form a third common input terminal of the three-level five-phase chopper circuit (702); The fourth switch tube and the fifth switch tube are connected to form the output end of the three-level five-phase chopper circuit (702), and the control ends of the third switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are all connected to the control circuit.

5. The star-connected five-phase power converter according to claim 4, characterized in that: The first five-phase transformer (203) comprises a first transformer to a fifth transformer, wherein the primary sides of the first transformer to the fifth transformer each have a first input terminal and a second input terminal, and the secondary sides of the first transformer to the fifth transformer each have a first output terminal and a second output terminal; The first input ends of the first transformer to the fifth transformer in the first five-phase transformer (203) are respectively connected to the output ends of the first five-phase chopper circuit (201) via the resonant circuit (202), and the second input ends of the first transformer to the fifth transformer in the first five-phase transformer (203) are respectively connected to each other; The second output ends of the first five-phase transformer (203) are connected to each other, and the first output end of the first five-phase transformer (203) is connected to the input end of the first five-phase rectifier circuit (204); Alternatively, the second input ends of the first transformer to the fifth transformer of the first five-phase transformer (203) are respectively connected, the second output ends of the first transformer to the fifth transformer of the first five-phase transformer (203) are respectively connected to the first output end of the next transformer, and the first output end of the first five-phase transformer (203) is connected to the input end of the first five-phase rectifier circuit (204).

6. The star-connected five-phase power converter according to claim 5, characterized in that: The resonant circuit (202) includes a plurality of series / parallel inductance circuits and capacitance circuits.

7. The star-connected five-phase power converter according to claim 5, characterized in that: The first five-phase rectifier circuit (204) has five input terminals, a first common output terminal and a second common output terminal; the first five-phase rectifier circuit (204) comprises: five parallel rectifier branches, the rectifier branches comprising a first power semiconductor device and a second power semiconductor device; The first ends of the first power semiconductor devices in the parallel rectifier branches are connected to form a first common output end, and the second ends of the second power semiconductor devices in the parallel rectifier branches are connected to form a second common output end; The first end of the first power semiconductor device is connected to the first common output end of the first five-phase rectifier circuit (204), the second end of the second power semiconductor device is connected to the second common output end of the first five-phase rectifier circuit (204), and the first power semiconductor device and the second power semiconductor device of each rectifier branch are connected to form an input end of the first five-phase rectifier circuit (204).

8. The star-connected five-phase power converter according to claim 7, characterized in that: The filtering circuit (600) comprises: A differential mode inductor, a first end of which is connected to a first common output end of the first five-phase rectifier circuit (204); A first filtering branch, a first end of which is connected to the second end of the differential mode inductor, and a second end of which is connected to the second common output end of the first five-phase rectifying circuit (204); The common mode inductor comprises a first winding and a second winding, wherein a first end of the first winding and a first end of the second winding are respectively connected to a first end and a second end of a first capacitor branch; The second filtering branch has a first end and a second end connected to the second end of the first winding of the common-mode inductor and the second end of the second winding of the common-mode inductor respectively.

9. The star-connected five-phase power converter according to any one of claims 1 to 8, characterized in that: The star-connected five-phase power converter further comprises a second five-phase chopper circuit (301), a second five-phase transformer (303) and a second five-phase rectifier circuit (304) respectively adjacent to the first five-phase chopper circuit (201), the first five-phase transformer (203) and the first five-phase rectifier circuit (204); Wherein, each of the first five-phase chopper circuits (201) and each of the second five-phase chopper circuits (301) are connected in parallel; or the second common input terminal of the first five-phase chopper circuit (201) is connected to the first common input terminal of the second five-phase chopper circuit (301); The first input end of each transformer primary side of the first five-phase transformer (203) is connected to the corresponding output end of the first five-phase chopper circuit (201) through the corresponding resonant circuit (202), the second input end of each transformer primary side of the first five-phase transformer (203) is connected to the corresponding first input end of each transformer primary side of the second five-phase transformer (303), and the second input end of each transformer primary side of each second five-phase transformer (303) is connected to the corresponding output end of the second five-phase chopper circuit (301); The second output ends of the secondary sides of the first five-phase transformer (203) are connected to each other, and the second output ends of the secondary sides of the second five-phase transformer (303) are connected to each other; and the first output end of each transformer of the second five-phase transformer (303) is connected to the input end of the corresponding second five-phase rectifier circuit (304); Alternatively, the second output end of each transformer secondary side of the first five-phase transformer (203) is connected to the first output end of the transformer secondary side of the next stage, and the second output end of the last transformer is connected to the first output end of the first transformer; the second output end of each transformer secondary side of the second five-phase transformer (303) is connected to the first output end of the transformer secondary side of the next stage, and the second output end of the last transformer is connected to the first output end of the first transformer; and the first output end of each transformer of the second five-phase transformer (303) is connected to the input end of the corresponding second five-phase rectifier circuit (304); The output end of the first five-phase rectifier circuit (204) and the output end of the second five-phase rectifier circuit (304) are connected in parallel and are both connected to the input end of the filter circuit (600), and the output end of the filter circuit (600) is connected to a load.

10. The star-connected five-phase power converter according to claim 9, characterized in that: The star-connected five-phase power converter further comprises a plurality of input filter capacitors (800) and a plurality of output filter capacitors (900); The input filter capacitor (800) is connected in parallel between the first common input terminal and the second common input terminal of the first five-phase chopper circuit (201), and another input filter capacitor (800) is connected in parallel between the first common input terminal and the second common input terminal of the second five-phase chopper circuit (301); The output filter capacitor (900) is connected in parallel between the first common output terminal and the second common output terminal of the first five-phase rectifier circuit (204), and another output filter capacitor (900) is connected in parallel between the first common output terminal and the second common output terminal of the second five-phase rectifier circuit (304).

11. A charging device, characterized in that: A star-connected five-phase power converter comprising any one of claims 1-10.

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