DC-DC converter and charging pile
By employing switching circuits, LC resonant circuits, and transformer modules in the DC-DC converter, and utilizing a design with the same magnetic core winding, the problem of uneven current distribution caused by differences in transformer parameters is solved, thereby improving the stability of the converter and reducing costs.
Patent Information
- Application Number
- CN202422395923.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2034-09-29
AI Technical Summary
In existing DC-DC converters, the difference in transformer parameters between the two DC-DC power conversion circuits leads to uneven current distribution in the rectifier circuit, affecting the stability of the converter.
By employing a switching circuit, an LC resonant circuit, and a transformer module, and by winding the secondary winding of the transformer on the same magnetic core, the current distribution of the rectifier circuit is made uniform, thereby improving the stability of the converter.
This achieves uniform current distribution in the rectifier circuit, improving the stability of the DC-DC converter and reducing costs.
Smart Images
Figure CN223942596U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power supply technology, and in particular to a DC-DC converter and a charging pile. Background Technology
[0002] A direct current to direct current (DCDC) converter can convert DC power into DC power of different voltages.
[0003] To increase the output voltage of a DC-DC converter, related technologies connect two DC-DC power conversion circuits in parallel. In the first DC-DC power conversion circuit, the first transformer is connected to the first rectifier circuit, and in the second DC-DC power conversion circuit, the second transformer is connected to the second rectifier circuit. However, the parameters of the first and second transformers differ, resulting in uneven current distribution between them. This, in turn, leads to uneven current distribution between the first and second rectifier circuits, reducing the stability of the DC-DC converter. Utility Model Content
[0004] Based on the above problems, this application provides a DC-DC converter and a charging pile, wherein the current of the first rectifier circuit and the second rectifier circuit is evenly distributed, thereby improving the stability of the DC-DC converter.
[0005] This embodiment discloses the following technical solution:
[0006] In a first aspect, embodiments of this application provide a DC-DC converter, including: a switching circuit, an LC resonant circuit, a transformer module, a first rectifier circuit, and a second rectifier circuit;
[0007] A transformer module includes a primary winding, a first secondary winding, and a second secondary winding;
[0008] The first end of the switching circuit is used to connect to the DC side, and the second end of the switching circuit is connected to the primary winding of the transformer module through the LC resonant circuit. The first secondary winding of the transformer module is connected to the first rectifier circuit, and the second secondary winding of the transformer module is connected to the second rectifier circuit.
[0009] Optionally, when the DC-DC converter is applied to a three-phase system, the switching circuit includes a three-phase switching circuit, the LC resonant circuit includes a first LC resonant circuit, a second LC resonant circuit, and a third LC resonant circuit, the transformer module includes a first transformer module, a second transformer module, and a third transformer module, the first rectifier circuit includes a first three-phase rectifier circuit, and the second rectifier circuit includes a second three-phase rectifier circuit; wherein, the first LC resonant circuit corresponds to the first transformer module, the second LC resonant circuit corresponds to the second transformer module, and the third LC resonant circuit corresponds to the third transformer module.
[0010] Optionally, the first transformer module includes a first transformer, the second transformer module includes a second transformer, and the third transformer module includes a third transformer;
[0011] The first LC resonant circuit and the primary winding of the first transformer are connected in series to form the first LLC resonant circuit; the second LC resonant circuit and the primary winding of the second transformer are connected in series to form the second LLC resonant circuit; and the third LC resonant circuit and the primary winding of the third transformer are connected in series to form the third LLC resonant circuit.
[0012] The primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a triangular or star configuration.
[0013] Optionally, the first secondary winding of the first transformer, the first secondary winding of the second transformer, and the first secondary winding of the third transformer are connected in a delta configuration and connected to the first three-phase rectifier circuit, and the second secondary windings of the first transformer, the second secondary winding of the second transformer, and the second secondary winding of the third transformer are connected in a delta configuration and connected to the second three-phase rectifier circuit; or, the first secondary winding of the first transformer, the first secondary winding of the second transformer, and the first secondary winding of the third transformer are connected in a star configuration and connected to the first three-phase rectifier circuit, and the second secondary windings of the first transformer, the second secondary winding of the second transformer, and the second secondary winding of the third transformer are connected in a star configuration and connected to the second three-phase rectifier circuit.
[0014] Optionally, the first transformer module includes the fourth and fifth transformers, the second transformer module includes the sixth and seventh transformers, and the third transformer module includes the eighth and ninth transformers.
[0015] The first LC resonant circuit, the primary winding of the fourth transformer, and the primary winding of the fifth transformer are connected in series to form the fourth LLC resonant circuit. The second LC resonant circuit, the primary winding of the sixth transformer, and the primary winding of the seventh transformer are connected in series to form the fifth LLC resonant circuit. The third LC resonant circuit, the primary winding of the eighth transformer, and the primary winding of the ninth transformer are connected in series to form the sixth LLC resonant circuit.
[0016] Optionally, the primary sides of the fourth LLC resonant circuit, the fifth LLC resonant circuit, and the sixth LLC resonant circuit are connected in a triangular or star configuration.
[0017] Optionally, the first secondary winding of the fourth transformer and the first secondary winding of the fifth transformer are connected in parallel to form a first parallel winding; the second secondary winding of the fourth transformer and the second secondary winding of the fifth transformer are connected in parallel to form a second parallel winding; the first secondary winding of the sixth transformer and the first secondary winding of the seventh transformer are connected in parallel to form a third parallel winding; the second secondary winding of the sixth transformer and the second secondary winding of the seventh transformer are connected in parallel to form a fourth parallel winding; the first secondary winding of the eighth transformer and the first secondary winding of the ninth transformer are connected in parallel to form a fifth parallel winding; and the second secondary winding of the eighth transformer and the second secondary winding of the ninth transformer are connected in parallel to form a sixth parallel winding. The first, third, and fifth parallel windings are connected to a first three-phase rectifier circuit, and the second, fourth, and sixth parallel windings are connected to a second three-phase rectifier circuit.
[0018] Optionally, the first parallel winding, the third parallel winding, and the fifth parallel winding are connected in a delta configuration and connected to the first three-phase rectifier circuit, and the second parallel winding, the fourth parallel winding, and the sixth parallel winding are connected in a delta configuration and connected to the second three-phase rectifier circuit; or, the first parallel winding, the third parallel winding, and the fifth parallel winding are connected in a star configuration and connected to the first three-phase rectifier circuit, and the second parallel winding, the fourth parallel winding, and the sixth parallel winding are connected in a star configuration and connected to the second three-phase rectifier circuit.
[0019] Optionally, it also includes: a power switching circuit;
[0020] The input terminal of the power switching circuit is connected to the output terminal of the first rectifier circuit and the output terminal of the second rectifier circuit.
[0021] A power switching circuit is used to connect the first rectifier circuit and the second rectifier circuit in series or in parallel.
[0022] Secondly, embodiments of this application provide a charging pile, including: an AC / DC power conversion circuit and a DC / DC converter as described in any embodiment of the first aspect;
[0023] The DC side of the AC-DC power conversion circuit is connected to the first terminal of the DC-DC converter, and the second terminal of the DC-DC converter is used to connect to the device to be charged.
[0024] When two DC-DC power conversion circuits are connected in parallel, the transformer parameters in the two circuits differ, leading to uneven current distribution between the first and second rectifier circuits. To address this, this application provides a DC-DC converter comprising: a switching circuit, an LC resonant circuit, a transformer module, a first rectifier circuit, and a second rectifier circuit. The transformer module includes a primary winding, a first secondary winding, and a second secondary winding. The first terminal of the switching circuit is connected to the DC side, and the second terminal is connected to the primary winding of the transformer module via the LC resonant circuit. The first secondary winding of the transformer module is connected to the first rectifier circuit, and the second secondary winding is connected to the second rectifier circuit. In this embodiment, the first secondary winding of the transformer is connected to the first rectifier circuit, and the second secondary winding is connected to the second rectifier circuit. The first and second secondary windings are wound on the same magnetic core, resulting in a more even current distribution between the first and second rectifier circuits and improving the stability of the DC-DC converter. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of a DC-DC converter provided in this embodiment;
[0027] Figure 2 This is a schematic diagram of another DC-DC converter provided in this embodiment;
[0028] Figure 3 This is a schematic diagram of the connection of the primary side of a transformer provided in this embodiment;
[0029] Figure 4 This is a schematic diagram of the connection of the secondary side of a transformer provided in this embodiment;
[0030] Figure 5 This is another schematic diagram of the primary side connection of a transformer provided in an embodiment of this application;
[0031] Figure 6 This is another schematic diagram of the connection of the secondary side of a transformer provided in an embodiment of this application;
[0032] Figure 7 A schematic diagram of another DC-DC converter provided in the embodiments of this application;
[0033] Figure 8This is a schematic diagram of a charging pile provided in an embodiment of this application. Detailed Implementation
[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0035] The terms "first" and "second," etc., used in the specification and claims of this utility model are used to distinguish different objects, not to describe a specific order of objects. For example, "first rectifier circuit data" and "second rectifier circuit," etc., are used to distinguish different rectifier circuits, not to describe a specific order of rectifier circuits.
[0036] In this embodiment, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this embodiment should not be construed as being better or more advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.
[0037] In the description of this embodiment, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.
[0038] See Figure 1 The figure is a schematic diagram of the structure of a DC-DC converter provided in an embodiment of this application.
[0039] like Figure 1 As shown, the DC-DC converter 100 includes: a switching circuit 110, an LC resonant circuit 120, a transformer module 130, a first rectifier circuit 140, and a second rectifier circuit 150.
[0040] A transformer module includes a primary winding, a first secondary winding, and a second secondary winding;
[0041] The first end of the switching circuit 110 is used to connect the DC+ and DC- sides. The second end of the switching circuit 110 is connected to the primary winding of the transformer module 130 through the LC resonant circuit 120. The first secondary winding of the transformer module 130 is connected to the first rectifier circuit 140, and the second secondary winding of the transformer module 130 is connected to the second rectifier circuit 150.
[0042] The number of turns in the first secondary winding is the same as the number of turns in the second secondary winding.
[0043] In this embodiment, the first secondary winding of the transformer connected to the first rectifier circuit and the second secondary winding connected to the second rectifier circuit are wound on the same magnetic core, which makes the current in the first rectifier circuit and the second rectifier circuit evenly distributed, improving the stability of the DC-DC converter. Furthermore, this embodiment uses only one transformer, reducing the cost of the DC-DC converter.
[0044] It should be understood that if the first rectifier circuit and the second rectifier circuit do not have equal current, it will cause some components to be overloaded, thereby shortening their service life and affecting the stability of the DC-DC converter.
[0045] This application does not specifically limit the application scenario of the DC-DC converter. For example, the DC-DC converter can be applied to single-phase or three-phase scenarios. When the DC-DC converter is applied to a single-phase scenario, its corresponding structural diagram can be found again. Figure 1 Based on the foregoing, DC-DC converters for single-phase applications will not be discussed further here. When a DC-DC converter is applied to a three-phase scenario, its corresponding structural diagram is shown below. Figure 2 As shown.
[0046] exist Figure 2 In the circuit, the switching circuit 110 includes a three-phase switching circuit, the LC resonant circuit 120 includes a first LC resonant circuit, a second LC resonant circuit, and a third LC resonant circuit, the transformer module 130 includes a first transformer module 1301, a second transformer module 1302, and a third transformer module 1303, the first rectifier circuit 140 includes a first three-phase rectifier circuit, and the second rectifier circuit 150 includes a second three-phase rectifier circuit; wherein, the first LC resonant circuit corresponds to the first transformer module 1301, the second LC resonant circuit corresponds to the second transformer module 1302, and the third LC resonant circuit corresponds to the third transformer module 1303.
[0047] The embodiments of this application do not specifically limit the structure of the first three-phase rectifier circuit and the second three-phase rectifier circuit. For example, the first three-phase rectifier circuit and the second three-phase rectifier circuit can be any one of a three-phase half-wave controlled rectifier circuit, a three-phase bridge fully controlled rectifier circuit, and a three-phase controlled rectifier circuit.
[0048] The embodiments of this application do not specifically limit the structure of the LC resonant circuit. For example, the LC resonant circuit can be composed of a capacitor and an inductor connected in series, or it can be composed of a capacitor and an inductor connected in parallel.
[0049] The embodiments of this application do not specifically limit the structure of the three-phase switching circuit. For example, the three-phase switching circuit can be a three-phase two-level bridge circuit or a three-phase three-level bridge circuit.
[0050] In one possible implementation, the first transformer module includes a transformer, for example, the first transformer module includes a first transformer T1, the second transformer module includes a second transformer T2, and the third transformer module includes a third transformer T3. The first LC resonant circuit and the primary winding Np1 of the first transformer T1 form a first LLC resonant circuit; the second LC resonant circuit and the primary winding Np2 of the second transformer T2 form a second LLC resonant circuit; and the third LC resonant circuit and the primary winding Np3 of the third transformer T3 form a third LLC resonant circuit.
[0051] The embodiments of this application do not specifically limit the connection relationship between the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit. For example, the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected by a star connection or a delta connection.
[0052] like Figure 3 As shown in (a), the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a star configuration. The first LLC resonant circuit includes a primary winding Np1 of a first capacitor C1, a first inductor L1, and a T1 connected in series (the first end of the first capacitor C1 is connected to the three-phase switching circuit, the second end of the first capacitor C1 is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is connected to the first end of Np1); the second LLC resonant circuit includes a primary winding Np2 of a second capacitor C2, a second inductor L2, and a T2 connected in series (the first end of the second capacitor C2 is connected to the three-phase switching circuit, the second end of the second capacitor C2 is connected to the first end of the second inductor L2, and the second end of the second inductor L2 is connected to the first end of Np2); the third LLC resonant circuit includes a primary winding Np3 of a third capacitor C3, a third inductor L3, and a T3 connected in series (the first end of the third capacitor C3 is connected to the three-phase switching circuit, the second end of the third capacitor C3 is connected to the first end of the third inductor L3, and the second end of the third inductor L3 is connected to the first end of Np3), and the second ends of Np1, Np2, and Np3 are connected together.
[0053] In this embodiment, the primary windings of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a star configuration, which can reduce the voltage across the primary winding and reduce the number of turns in the primary winding to reduce the size of the transformer.
[0054] like Figure 3As shown in (b), the primary windings of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a delta configuration. The first LLC resonant circuit includes the primary winding Np1 of a first capacitor C1, a first inductor L1, and T1 connected in series (the first terminal of the first capacitor C1 is connected to the three-phase switching circuit, the second terminal of the first capacitor C1 is connected to the first terminal of the first inductor L1, and the second terminal of the first inductor L1 is connected to the first terminal of Np1). The second LLC resonant circuit includes the primary winding Np2 of a second capacitor C2, a second inductor L2, and T2 connected in series (the first terminal of the second capacitor C2 is connected to the three-phase switching circuit, and the second terminal of the second capacitor C2 is connected to the first terminal of the second inductor L2). One end of the circuit consists of the second end of the second inductor L2 connected to the first end of Np2; the third LLC resonant circuit includes the third capacitor C3, the third inductor L3 and the primary winding Np3 of T3 connected in series (the first end of the third capacitor C3 is connected to the three-phase switching circuit, the second end of the third capacitor C3 is connected to the first end of the third inductor L3, and the second end of the third inductor L3 is connected to the first end of Np3); the second end of Np1 is connected to the first end of the second capacitor C2, the second end of Np2 is connected to the first end of the third capacitor C3, and the second end of Np3 is connected to the first end of the first capacitor C1.
[0055] In this embodiment, the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a delta configuration. If one of the first transformer T1, the second transformer T2, and the third transformer T3 fails or is disabled, the other two transformers will continue to provide power of equal capacity, thereby improving the fault resistance of the DC-DC converter.
[0056] The embodiments of this application do not specifically limit the connection relationship between the first secondary winding NsA1 and the second secondary winding NsB1 of the first transformer T1, the first secondary winding NsA2 and the second secondary winding NsB2 of the second transformer T2, and the first secondary winding NsA3 and the second secondary winding NsB3 of the third transformer T3. For example, NsA1, NsA2 and NsA3 are connected in a star configuration, and NsB1, NsB2 and NsB3 are connected in a star configuration, or NsA1, NsA2 and NsA3 are connected in a delta configuration, and NsB1, NsB2 and NsB3 are connected in a delta configuration.
[0057] like Figure 4As shown in (a), NsA1, NsA2, and NsA3 are connected in a star configuration, as are NsB1, NsB2, and NsB3. Specifically, the first terminals of NsA1, NsA2, and NsA3 are all connected to a first three-phase rectifier circuit, and the second terminals of NsA1, NsA2, and NsA3 are connected together. Similarly, the first terminals of NsB1, NsB2, and NsB3 are all connected to a second three-phase rectifier circuit, and the second terminals of NsB1, NsB2, and NsB3 are connected together.
[0058] In this embodiment, NsA1, NsA2, and NsA3 are connected in a star configuration, and NsB1, NsB2, and NsB3 are also connected in a star configuration. This can reduce the voltage across the first and second secondary windings, and reduce the number of turns in the first and second secondary windings to decrease the size of the transformer.
[0059] like Figure 4 As shown in (b), NsA1, NsA2, and NsA3 are connected in a delta configuration, as are NsB1, NsB2, and NsB3. Specifically, the first terminals of NsA1, NsA2, and NsA3 are all connected to the first three-phase rectifier circuit; the second terminal of NsA1 is connected to the first terminal of NsA2; the second terminal of NsA2 is connected to the first terminal of NsA3; and the second terminal of NsA3 is connected to the first terminal of NsA1. Similarly, the first terminals of NsB1, NsB2, and NsB3 are all connected to the second three-phase rectifier circuit; the second terminal of NsB1 is connected to the first terminal of NsB2; the second terminal of NsB2 is connected to the first terminal of NsB3; and the second terminal of NsB3 is connected to the first terminal of NsB1.
[0060] In this embodiment, NsA1, NsA2, and NsA3 are connected in a triangle, and NsB1, NsB2, and NsB3 are also connected in a triangle. If one of the first transformer T1, the second transformer T2, and the third transformer T3 fails or is disabled, the remaining two transformers will continue to provide power of equal capacity, thereby improving the fault resistance of the DC-DC converter.
[0061] As mentioned above, Figure 3 Figure (a) illustrates a schematic diagram showing the star-shaped connection between the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit. Figure 3 Figure (b) illustrates a schematic diagram showing the triangular connection between the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit. Figure 4Figure (a) illustrates a star-shaped connection between NsA1, NsA2, and NsA3, and a star-shaped connection between NsB1, NsB2, and NsB3. Figure 4 (b) in the diagram describes the triangular connections between NsA1, NsA2 and NsA3, and the triangular connections between NsB1, NsB2 and NsB3.
[0062] The DC-DC converter in this embodiment can... Figure 3 The two transformer primary connection methods in (a) and (b) are related to Figure 4 Combining the two transformer secondary connection methods (a) and (b) in the diagram, we obtain the following four transformer primary and secondary connection methods: The first method, Figure 3 (a) and Figure 4 In combination (a), the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a star configuration, NsA1, NsA2, and NsA3 are connected in a star configuration, and NsB1, NsB2, and NsB3 are connected in a star configuration; the second type, Figure 3 (a) and Figure 4 In combination (b), the primary sides of the first, second, and third LLC resonant circuits are connected in a star configuration, NsA1, NsA2, and NsA3 are connected in a triangle configuration, and NsB1, NsB2, and NsB3 are connected in a triangle configuration; the third type... Figure 3 (b) and Figure 4 In combination (a), the primary sides of the first, second, and third LLC resonant circuits are connected in a triangle, NsA1, NsA2, and NsA3 are connected in a star configuration, and NsB1, NsB2, and NsB3 are also connected in a star configuration; the fourth type... Figure 3 (b) and Figure 4 In combination (b) of the above, the primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a triangle, NsA1, NsA2, and NsA3 are connected in a triangle, and NsB1, NsB2, and NsB3 are connected in a triangle. Through these various connection methods of the primary and secondary sides of the transformer, the DC-DC converter described in this embodiment can be applied to various scenarios, increasing the applicability of the DC-DC converter.
[0063] In one possible implementation, the first transformer module includes two transformers, for example, the first transformer module includes a fourth transformer T4 and a fifth transformer T5; the second transformer module includes a sixth transformer T6 and a seventh transformer T7; and the third transformer module includes an eighth transformer T8 and a ninth transformer T9. The first LC resonant circuit, the primary winding Np4 of the fourth transformer T4, and the primary winding Np5 of the fifth transformer T5 form the fourth LLC resonant circuit; the second LC resonant circuit, the primary winding Np6 of the sixth transformer T6, and the primary winding Np7 of the seventh transformer T7 form the fifth LLC resonant circuit; and the third LC resonant circuit, the primary winding Np8 of the eighth transformer T8, and the primary winding Np9 of the ninth transformer T9 form the sixth LLC resonant circuit.
[0064] In this embodiment, each phase voltage corresponds to two transformers, which provides better heat dissipation performance compared to a single transformer.
[0065] like Figure 5 As shown in (a), the fourth LLC resonant circuit, the fifth LLC resonant circuit, and the sixth LLC resonant circuit are connected in a star configuration. The fourth LLC resonant circuit includes a fourth capacitor C4, a fourth inductor L4, the primary winding Np4 of T4, and the primary winding Np5 of T5 connected in series (the first terminal of the fourth capacitor C4 is connected to the three-phase switching circuit, the second terminal of the fourth capacitor C4 is connected to the first terminal of the fourth inductor L4, the second terminal of the fourth inductor L4 is connected to the first terminal of Np4, and the second terminal of Np4 is connected to the first terminal of Np5). The fifth LLC resonant circuit includes a fifth capacitor C5, a fifth inductor L5, the primary winding Np6 of T6, and the primary winding Np7 of T7 connected in series (the first terminal of the fifth capacitor C5 is connected to the three-phase switching circuit, the second terminal of the fifth capacitor C5 is connected to the first terminal of Np5, the second terminal of the fifth inductor L4 is connected to the first terminal of Np5, and the second terminal of Np4 is connected to the first terminal of Np5). The second terminal of the fifth inductor L5 is connected to the first terminal of the fifth inductor L5, the second terminal of the fifth inductor L5 is connected to the first terminal of Np6, and the second terminal of Np6 is connected to the first terminal of Np7. The sixth LLC resonant circuit includes the sixth capacitor C6, the sixth inductor L6, the primary winding Np8 of T8 and the primary winding Np9 of T9 connected in series (the first terminal of the sixth capacitor C6 is connected to the three-phase switching circuit, the second terminal of the sixth capacitor C6 is connected to the first terminal of the sixth inductor L6, the second terminal of the sixth inductor L6 is connected to the first terminal of Np8, and the second terminal of Np8 is connected to the first terminal of Np9). The second terminals of Np5, Np7 and Np9 are connected together.
[0066] In this embodiment, the primary windings of the fourth LLC resonant circuit, the fifth LLC resonant circuit, and the sixth LLC resonant circuit are connected in a star configuration, which can reduce the voltage across the primary winding and reduce the number of turns in the primary winding to reduce the size of the transformer.
[0067] like Figure 5As shown in (b), the fourth, fifth, and sixth LLC resonant circuits are connected in a delta configuration. The fourth LLC resonant circuit includes a fourth capacitor C4, a fourth inductor L4, the primary winding Np4 of T4, and the primary winding Np5 of T5 connected in series (the first terminal of the fourth capacitor C4 is connected to the three-phase switching circuit, the second terminal of the fourth capacitor C4 is connected to the first terminal of the fourth inductor L4, the second terminal of the fourth inductor L4 is connected to the first terminal of Np4, and the second terminal of Np4 is connected to the first terminal of Np5). The fifth LLC resonant circuit includes a fifth capacitor C5, a fifth inductor L5, the primary winding Np6 of T6, and the primary winding Np7 of T7 connected in series (the first terminal of the fifth capacitor C5 is connected to the three-phase switching circuit, and the second terminal of the fifth capacitor C5 is connected to the first terminal of the fifth inductor L5). The second terminal of the fifth inductor L5 is connected to the first terminal of Np6, and the second terminal of Np6 is connected to the first terminal of Np7. The sixth LLC resonant circuit includes the sixth capacitor C6, the sixth inductor L6, the primary winding Np8 of T8, and the primary winding Np9 of T9, all connected in series (the first terminal of the sixth capacitor C6 is connected to the three-phase switching circuit, the second terminal of the sixth capacitor C6 is connected to the first terminal of the sixth inductor L6, the second terminal of the sixth inductor L6 is connected to the first terminal of Np8, and the second terminal of Np8 is connected to the first terminal of Np9). The second terminal of Np5 is connected to the first terminal of the fifth capacitor C5, the second terminal of Np7 is connected to the first terminal of the sixth capacitor C6, and the second terminal of Np9 is connected to the first terminal of the fourth capacitor C4.
[0068] The primary sides of the fourth, fifth, and sixth LLC resonant circuits are connected in a delta configuration. If one set of transformers fails or becomes disabled, the other two sets of transformers will continue to provide power of equal capacity, thus improving the fault tolerance of the DC-DC converter.
[0069] In this embodiment, the first secondary winding of the fourth transformer and the first secondary winding of the fifth transformer are connected in parallel to form a first parallel winding; the second secondary winding of the fourth transformer and the second secondary winding of the fifth transformer are connected in parallel to form a second parallel winding; the first secondary winding of the sixth transformer and the first secondary winding of the seventh transformer are connected in parallel to form a third parallel winding; the second secondary winding of the sixth transformer and the second secondary winding of the seventh transformer are connected in parallel to form a fourth parallel winding; the first secondary winding of the eighth transformer and the first secondary winding of the ninth transformer are connected in parallel to form a fifth parallel winding; and the second secondary winding of the eighth transformer and the second secondary winding of the ninth transformer are connected in parallel to form a sixth parallel winding. The first, third, and fifth parallel windings are connected to a first three-phase rectifier circuit, and the second, fourth, and sixth parallel windings are connected to a second three-phase rectifier circuit.
[0070] This application does not specifically limit the first secondary winding NsA4 and the second secondary winding NsB4 of the fourth transformer T4, the first secondary winding NsA5 and the second secondary winding NsB5 of the fifth transformer T5, the first secondary winding NsA6 and the second secondary winding NsB6 of the sixth transformer T6, the first secondary winding NsA7 and the second secondary winding NsB7 of the seventh transformer T7, the first secondary winding NsA8 and the second secondary winding NsB8 of the eighth transformer T8, or the first secondary winding NsA9 of the ninth transformer T9. The connection relationship between the second secondary winding NsB9 is as follows: for example, NsA4, NsA5, NsA6, NsA7, NsA8 and NsA9 are connected in a star configuration, and NsB4, NsB5, NsB6, NsB7, NsB8 and NsB9 are connected in a star configuration; or, NsA4, NsA5, NsA6, NsA7, NsA8 and NsA9 are connected in a delta configuration, and NsB4, NsB5, NsB6, NsB7, NsB8 and NsB9 are connected in a delta configuration.
[0071] like Figure 6 As shown in (a), NsA4 and NsA5 are connected in parallel (i.e., the first parallel winding), NsA6 and NsA7 are connected in parallel (i.e., the third parallel winding), NsA8 and NsA9 are connected in parallel (i.e., the fifth parallel winding), NsB4 and NsB5 are connected in parallel (i.e., the second parallel winding), NsB6 and NsB7 are connected in parallel (i.e., the fourth parallel winding), and NsB8 and NsB9 are connected in parallel (i.e., the sixth parallel winding). The first, third, and fifth parallel windings are connected to the first three-phase rectifier circuit through a star connection, and the second, fourth, and sixth parallel windings are connected to the second three-phase rectifier circuit through a star connection. Specifically, the first end of NsA4 is connected to the first end of NsA5, the second end of NsA4 is connected to the second end of NsA5, the first end of NsA6 is connected to the first end of NsA7, the second end of NsA6 is connected to the second end of NsA7, the first end of NsA8 is connected to the first end of NsA9, and the second end of NsA8 is connected to the second end of NsA9; the first end of NsB4 is connected to the first end of NsB5, the second end of NsB4 is connected to the second end of NsB5, the first end of NsB6 is connected to the first end of NsB7, and the second end of NsB6 is connected to the first end of NsB7. Two terminals: the first terminal of NsB8 is connected to the first terminal of NsB9, and the second terminal of NsB8 is connected to the second terminal of NsB9; the second terminal of NsA5 is connected to the second terminal of NsA6, the second terminal of NsB5 is connected to the second terminal of NsB6, the second terminal of NsA7 is connected to the second terminal of NsA8, and the second terminal of NsB7 is connected to the second terminal of NsB8; the first terminals of NsA5, NsA6, and NsA8 are connected to the first three-phase rectifier circuit, and the first terminals of NsB5, NsB7, and NsB8 are connected to the second three-phase rectifier circuit.
[0072] In this embodiment, NsA4 and NsA5 are connected in parallel (i.e., the first parallel winding), NsA6 and NsA7 are connected in parallel (i.e., the third parallel winding), NsA8 and NsA9 are connected in parallel (i.e., the fifth parallel winding), NsB4 and NsB5 are connected in parallel (i.e., the second parallel winding), NsB6 and NsB7 are connected in parallel (i.e., the fourth parallel winding), and NsB8 and NsB9 are connected in parallel (i.e., the sixth parallel winding). The first, third, and fifth parallel windings are connected in a star configuration, and the second, fourth, and sixth parallel windings are connected in a star configuration. This reduces the voltage across the first and second secondary windings, and reduces the number of turns in the first and second secondary windings to decrease the transformer's size.
[0073] like Figure 6 As shown in (b), NsA4 and NsA5 are connected in parallel (i.e., the first parallel winding), NsA6 and NsA7 are connected in parallel (i.e., the third parallel winding), NsA8 and NsA9 are connected in parallel (i.e., the fifth parallel winding), NsB4 and NsB5 are connected in parallel (i.e., the second parallel winding), NsB6 and NsB7 are connected in parallel (i.e., the fourth parallel winding), and NsB8 and NsB9 are connected in parallel (i.e., the sixth parallel winding). The first, third, and fifth parallel windings are connected to the first three-phase rectifier circuit through a delta connection, and the second, fourth, and sixth parallel windings are connected to the second three-phase rectifier circuit through a delta connection. Specifically, the first end of NsA4 is connected to the first end of NsA5, the second end of NsA4 is connected to the second end of NsA5, the first end of NsA6 is connected to the first end of NsA7, the second end of NsA6 is connected to the second end of NsA7, the first end of NsA8 is connected to the first end of NsA9, and the second end of NsA8 is connected to the second end of NsA9; the first end of NsB4 is connected to the first end of NsB5, the second end of NsB4 is connected to the second end of NsB5, the first end of NsB6 is connected to the first end of NsB7, the second end of NsB6 is connected to the second end of NsB7, and the first end of NsB8 is connected to the first end of NsB9. At one end, the second end of NsB8 is connected to the second end of NsB9; the first end of NsA5 is connected to the second end of NsA8, the second end of NsA5 is connected to the first end of NsA6, the first end of NsB5 is connected to the second end of NsB8, the second end of NsB5 is connected to the first end of NsB6, the second end of NsA7 is connected to the first end of NsA8, and the second end of NsB7 is connected to the first end of NsB8; the first ends of NsA5, NsA6, and NsA8 are connected to the first three-phase rectifier circuit, and the first ends of NsB7, NsB8, and NsB9 are connected to the second three-phase rectifier circuit.
[0074] In this embodiment, NsA4 and NsA5 are connected in parallel (i.e., the first parallel winding), NsA6 and NsA7 are connected in parallel (i.e., the third parallel winding), NsA8 and NsA9 are connected in parallel (i.e., the fifth parallel winding), NsB4 and NsB5 are connected in parallel (i.e., the second parallel winding), NsB6 and NsB7 are connected in parallel (i.e., the fourth parallel winding), and NsB8 and NsB9 are connected in parallel (i.e., the sixth parallel winding). The first, third, and fifth parallel windings are connected in a delta configuration, and the second, fourth, and sixth parallel windings are connected in a delta configuration. If one of the fourth transformer T4, fifth transformer T5, sixth transformer T6, seventh transformer T7, eighth transformer T8, and ninth transformer T9 fails or is disabled, the remaining transformers will continue to provide power of equal capacity, thereby improving the fault resistance capability of the DC-DC converter.
[0075] Figure 5 Figure (a) illustrates a schematic diagram showing the star-shaped connection between the primary sides of the fourth, fifth, and sixth LLC resonant circuits. Figure 5 (b) in the diagram describes a schematic diagram showing the triangular connection between the primary sides of the fourth, fifth, and sixth LLC resonant circuits. Figure 6 Figure (a) illustrates a star-shaped connection between NsA4, NsA5, NsA6, NsA7, NsA8, and NsA9, and a star-shaped connection between NsB4, NsB5, NsB6, NsB7, NsB8, and NsB9. Figure 4 (b) in the diagram describes a triangular connection between NsA4, NsA5, NsA6, NsA7, NsA8 and NsA9, and a triangular connection between NsB4, NsB5, NsB6, NsB7, NsB8 and NsB9.
[0076] The DC-DC converter in this embodiment can... Figure 5 The two transformer primary connection methods in (a) and (b) are related to Figure 6 Combining the two transformer secondary connection methods (a) and (b) in the diagram, we obtain the following four transformer primary and secondary connection methods: The first method, Figure 5 (a) and Figure 6 In combination (a), the primary sides of the fourth, fifth, and sixth LLC resonant circuits are connected in a star configuration, NsA4, NsA5, NsA6, NsA7, NsA8, and NsA9 are connected in a star configuration, and NsB4, NsB5, NsB6, NsB7, NsB8, and NsB9 are connected in a star configuration; the second type, Figure 5 (a) and Figure 6In combination (b), the primary sides of the fourth, fifth, and sixth LLC resonant circuits are connected in a star configuration, meaning NsA4, NsA5, NsA6, NsA7, NsA8, and NsA9 are connected in a triangle configuration, and NsB4, NsB5, NsB6, NsB7, NsB8, and NsB9 are also connected in a triangle configuration; the third type, Figure 5 (b) and Figure 6 In combination (a), the primary sides of the fourth, fifth, and sixth LLC resonant circuits are connected in a triangular configuration, NsA4, NsA5, NsA6, NsA7, NsA8, and NsA9 are connected in a star configuration, and NsB4, NsB5, NsB6, NsB7, NsB8, and NsB9 are also connected in a star configuration; the fourth type, Figure 5 (b) and Figure 6 In combination (b) of the above, the primary sides of the fourth, fifth, and sixth LLC resonant circuits are connected in a triangle, NsA4, NsA5, NsA6, NsA7, NsA8, and NsA9 are connected in a triangle, and NsB4, NsB5, NsB6, NsB7, NsB8, and NsB9 are connected in a triangle. Through these various connection methods of the transformer's primary and secondary sides, the DC-DC converter described in this embodiment can be applied to various scenarios, increasing the applicability of the DC-DC converter.
[0077] To expand the voltage output range of the DC-DC converter, this application also provides a DC-DC converter. Its structural schematic diagram is shown below. Figure 7 As shown, the DC-DC converter also includes a power switching circuit 160; the input terminal of the power switching circuit 160 is connected to the output terminal of the first rectifier circuit 140 and the output terminal of the second rectifier circuit 150; the power switching circuit 160 is used to connect the first rectifier circuit 140 and the second rectifier circuit 150 in series or in parallel.
[0078] When the first rectifier circuit 140 and the second rectifier circuit 150 are connected in parallel, the positive output terminal of the first rectifier circuit 140 is connected to the positive output terminal of the second rectifier circuit 150, and the negative output terminal of the first rectifier circuit 140 is connected to the negative output terminal of the second rectifier circuit 150; when the first rectifier circuit 140 and the second rectifier circuit 150 are connected in series, the positive output terminal of the first rectifier circuit 140 is connected to the negative output terminal of the second rectifier circuit 150, and the negative output terminal of the first rectifier circuit 140 is connected to the positive output terminal of the second rectifier circuit 150.
[0079] In this embodiment, the first rectifier circuit and the second rectifier circuit are connected in series or in parallel through a power switching circuit, thereby expanding the voltage output range of the DC-DC converter.
[0080] In addition, this application embodiment also provides a charging pile, the structural schematic diagram of which is shown below. Figure 8 As shown.
[0081] like Figure 8 As shown, the charging pile includes: an AC / DC power conversion circuit 200 and a DC / DC converter 100 in any of the aforementioned embodiments; wherein, the DC side of the AC / DC power conversion circuit is connected to the first end of the DC / DC converter, and the second end of the DC / DC converter is used to connect to the device to be charged.
[0082] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments. In particular, the charging pile embodiment is basically similar to the DC-DC converter embodiment, so the description is relatively simple, and the relevant parts can be referred to the description of the DC-DC converter.
[0083] The above description is merely one specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A DC-DC converter, characterized in that, include: The system includes a switching circuit, an LC resonant circuit, a transformer module, a first rectifier circuit, and a second rectifier circuit; the transformer module includes a primary winding, a first secondary winding, and a second secondary winding. The first end of the switching circuit is used to connect to the DC side, and the second end of the switching circuit is connected to the primary winding of the transformer module through the LC resonant circuit. The first secondary winding of the transformer module is connected to the first rectifier circuit, and the second secondary winding of the transformer module is connected to the second rectifier circuit. When the DC-DC converter is applied to a three-phase system, the switching circuit includes a three-phase switching circuit, the LC resonant circuit includes a first LC resonant circuit, a second LC resonant circuit, and a third LC resonant circuit, the transformer module includes a first transformer module, a second transformer module, and a third transformer module, the first rectifier circuit includes a first three-phase rectifier circuit, and the second rectifier circuit includes a second three-phase rectifier circuit; wherein, the first LC resonant circuit corresponds to the first transformer module, the second LC resonant circuit corresponds to the second transformer module, and the third LC resonant circuit corresponds to the third transformer module.
2. The DC-DC converter according to claim 1, characterized in that, The first transformer module includes a first transformer, the second transformer module includes a second transformer, and the third transformer module includes a third transformer; The first LC resonant circuit and the primary winding of the first transformer are connected in series to form a first LLC resonant circuit; the second LC resonant circuit and the primary winding of the second transformer are connected in series to form a second LLC resonant circuit; and the third LC resonant circuit and the primary winding of the third transformer are connected in series to form a third LLC resonant circuit. The primary sides of the first LLC resonant circuit, the second LLC resonant circuit, and the third LLC resonant circuit are connected in a triangular or star configuration.
3. The DC-DC converter according to claim 2, characterized in that, The first secondary winding of the first transformer, the first secondary winding of the second transformer, and the first secondary winding of the third transformer are connected in a delta configuration and connected to the first three-phase rectifier circuit. The second secondary winding of the first transformer, the second secondary winding of the second transformer, and the second secondary winding of the third transformer are connected in a delta configuration and connected to the second three-phase rectifier circuit. Alternatively, the first secondary winding of the first transformer, the first secondary winding of the second transformer, and the first secondary winding of the third transformer are connected in a star configuration and connected to the first three-phase rectifier circuit, and the second secondary winding of the first transformer, the second secondary winding of the second transformer, and the second secondary winding of the third transformer are connected in a star configuration and connected to the second three-phase rectifier circuit.
4. The DC-DC converter according to claim 1, characterized in that, The first transformer module includes a fourth transformer and a fifth transformer, the second transformer module includes a sixth transformer and a seventh transformer, and the third transformer module includes an eighth transformer and a ninth transformer; The first LC resonant circuit, the primary winding of the fourth transformer, and the primary winding of the fifth transformer are connected in series to form the fourth LLC resonant circuit; the second LC resonant circuit, the primary winding of the sixth transformer, and the primary winding of the seventh transformer are connected in series to form the fifth LLC resonant circuit; and the third LC resonant circuit, the primary winding of the eighth transformer, and the primary winding of the ninth transformer are connected in series to form the sixth LLC resonant circuit.
5. The DC-DC converter according to claim 4, characterized in that, The primary sides of the fourth LLC resonant circuit, the fifth LLC resonant circuit, and the sixth LLC resonant circuit are connected in a triangular or star configuration.
6. The DC-DC converter according to claim 5, characterized in that, The first secondary winding of the fourth transformer and the first secondary winding of the fifth transformer are connected in parallel to form a first parallel winding; the second secondary winding of the fourth transformer and the second secondary winding of the fifth transformer are connected in parallel to form a second parallel winding; the first secondary winding of the sixth transformer and the first secondary winding of the seventh transformer are connected in parallel to form a third parallel winding; the second secondary winding of the sixth transformer and the second secondary winding of the seventh transformer are connected in parallel to form a fourth parallel winding; the first secondary winding of the eighth transformer and the first secondary winding of the ninth transformer are connected in parallel to form a fifth parallel winding; and the second secondary winding of the eighth transformer and the second secondary winding of the ninth transformer are connected in parallel to form a sixth parallel winding. The first parallel winding, the third parallel winding, and the fifth parallel winding are connected to the first three-phase rectifier circuit, and the second parallel winding, the fourth parallel winding, and the sixth parallel winding are connected to the second three-phase rectifier circuit.
7. The DC-DC converter according to claim 6, characterized in that, The first parallel winding, the third parallel winding, and the fifth parallel winding are connected in a delta configuration and connected to the first three-phase rectifier circuit, and the second parallel winding, the fourth parallel winding, and the sixth parallel winding are connected in a delta configuration and connected to the second three-phase rectifier circuit. Alternatively, the first parallel winding, the third parallel winding, and the fifth parallel winding are connected in a star configuration and connected to the first three-phase rectifier circuit, and the second parallel winding, the fourth parallel winding, and the sixth parallel winding are connected in a star configuration and connected to the second three-phase rectifier circuit.
8. The DC-DC converter according to any one of claims 1-7, characterized in that, Also includes: Power switching circuit; The input terminal of the power switching circuit is connected to the output terminal of the first rectifier circuit and the output terminal of the second rectifier circuit; The power switching circuit is used to connect the first rectifier circuit and the second rectifier circuit in series or in parallel.
9. A charging pile, characterized in that, include: An AC-DC power conversion circuit and a DC-DC converter as described in any one of claims 1-8; The DC side of the AC-DC power conversion circuit is connected to the first terminal of the DC-DC converter, and the second terminal of the DC-DC converter is used to connect to the device to be charged.