Dual active bridge converter, bidirectional DC conversion module and power supply device
By making adjacent transformers share non-winding post cores and winding the windings separately in a dual active bridge converter, the problem of large volume and weight of the magnetic components is solved, and more efficient energy conversion and loss reduction is achieved.
Patent Information
- Application Number
- CN202411393460.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2025-01-10
AI Technical Summary
The weight and volume of magnetic components in bidirectional DC-DC converters limit the lightweight, compactness and high efficiency development of the equipment.
By making adjacent transformers share non-winding post cores in a dual active bridge converter, and winding the primary winding and the secondary winding separately, the coupling is reduced and the leakage inductance is increased to replace the energy storage inductance, and the energy storage inductance is reduced. Use of inductive cores.
The volume and weight of the magnetic parts are significantly reduced, and the losses of the windings and cores are reduced, achieving more efficient energy conversion.
Smart Images
Figure CN119296929A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of high-power power electronic magnetic integration, and in particular to a dual active bridge converter, a bidirectional direct current conversion module and a power supply device. Background Art
[0002] With the increasing power consumption, bidirectional DC-DC converters play an increasingly important role in the modern electrical field due to their simple structure, high efficiency and bidirectional energy flow. Among them, magnetic components are key components of bidirectional DC-DC converters, which can realize the mutual conversion of electrical energy and magnetic energy to ensure the reliability and safety of the converter. They are heavy and large in size. According to statistics, the weight and volume of magnetic components are generally 20%-30% of the total weight and volume of the converter. This restricts the development of bidirectional DC-DC converters towards light weight, small size, high power density and high efficiency.
[0003] In some cases, for an N-phase dual active bridge converter, N inductors and N transformers are required. If a discrete magnetic design is adopted, 2*N magnetic components are required, which seriously violates the original intention of high efficiency and high power density. Summary of the invention
[0004] The present disclosure provides a dual active bridge converter, a bidirectional DC conversion module and a power supply device to solve the problem that magnetic components of a multi-phase dual active bridge converter are heavy and have a large volume.
[0005] In a first aspect, the present disclosure provides a dual active bridge converter, comprising a multi-phase transformer arranged and spliced in sequence, each phase transformer comprising a first winding column core, a second winding column core, a first non-winding column core, a second non-winding column core, a primary winding and a secondary winding; wherein the first winding column core, the first non-winding column core, the second winding column core and the second non-winding column core in each phase transformer are connected end to end, and the positions of the first winding column core and the second winding column core are opposite, and in two adjacent transformers, the first non-winding column core of the latter transformer and the second non-winding column core of the previous transformer are the same core, the primary winding in each phase transformer is wound on the first winding column core in the phase transformer, and the secondary winding in each phase transformer is wound on the second winding column core in the phase transformer.
[0006] In an exemplary embodiment, transformers of adjacent phases share a common non-wound-leg core.
[0007] In an exemplary embodiment, the winding directions of the primary winding and the secondary winding in the same phase transformer are consistent.
[0008] In an exemplary embodiment, air gaps are present inside the first winding leg magnetic core and the second winding leg magnetic core in each phase transformer.
[0009] In an exemplary embodiment, the winding directions of the primary windings and the secondary windings in all phase transformers are the same.
[0010] In an exemplary embodiment, the first winding leg magnetic core, the second winding leg magnetic core, the first non-winding leg magnetic core and the second non-winding leg magnetic core in each phase transformer are all strip-shaped magnetic cores.
[0011] In an exemplary embodiment, the first winding leg core, the first non-winding leg core, the second winding leg core, and the second non-winding leg core in each phase transformer are connected end to end to form a rectangular structure.
[0012] In an exemplary embodiment, the material used for the primary winding and the secondary winding includes at least one of copper foil, copper wire, aluminum wire and paper insulation tape.
[0013] In an exemplary embodiment, the first wound-leg magnetic core, the second wound-leg magnetic core, the first non-wound-leg magnetic core, and the second non-wound-leg magnetic core are all made of ferrite magnetic material.
[0014] In a second aspect, the present disclosure provides a bidirectional DC conversion module, comprising the dual active bridge converter described in the first aspect.
[0015] In a third aspect, the present disclosure provides a power supply device, comprising an input end, a voltage converter and an output end, wherein the voltage converter is the bidirectional DC conversion module described in the first aspect.
[0016] The dual active bridge converter provided by the present disclosure reduces the coupling between the primary winding and the secondary winding in the transformer by making adjacent transformers share the same non-winding column magnetic core and winding the primary winding and the secondary winding in each phase transformer separately, increases the leakage inductance of the transformer, and realizes the work of replacing the energy storage inductor with the leakage inductance of the transformer, thereby reducing the inductor magnetic core, and then significantly reducing the volume and weight of the magnetic component. In addition, by using the leakage inductance of the transformer to replace the energy storage inductor, the inductor winding and the inductor magnetic core can be reduced invisibly, which is conducive to reducing the winding loss and magnetic core loss of the converter. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:
[0018] Figure 1 A schematic structural diagram of a dual active bridge converter provided in an embodiment of the present disclosure.
[0019] Figure 2 A side view of a dual active bridge converter provided in an embodiment of the present disclosure.
[0020] Figure 3 A top view of a dual active bridge converter provided in an embodiment of the present disclosure.
[0021] Figure 4 A schematic diagram of a dual active bridge converter provided in an embodiment of the present disclosure.
[0022] Figure 5 An analysis diagram of the first phase transformer of a dual active bridge converter and a distribution diagram of the magnetic field intensity in the core window provided in an embodiment of the present disclosure.
[0023] Figure 6 A schematic diagram of an equivalent magnetic circuit of a dual active bridge converter provided in an embodiment of the present disclosure.
[0024] In the drawings, the same reference numerals are used for the same components and the drawings are not drawn to scale. DETAILED DESCRIPTION
[0025] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, and to fully understand and implement how the present disclosure applies technical means to solve technical problems and achieve the corresponding technical effects, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only embodiments of a part of the present disclosure, not all of the embodiments. The embodiments of the present disclosure and the various features in the embodiments can be combined with each other without conflict, and the technical solutions formed are all within the scope of protection of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present disclosure.
[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.
[0027] Example
[0028] The disclosed embodiment provides a dual active bridge converter, including a multi-phase transformer arranged and spliced in sequence, each phase transformer including a first winding column core, a second winding column core, a first non-winding column core, a second non-winding column core, a primary winding and a secondary winding. The first winding column core, the first non-winding column core, the second winding column core and the second non-winding column core in each phase transformer are connected end to end, and the first winding column core and the second winding column core are opposite to each other. In two adjacent transformers, the first non-winding column core of the latter transformer and the second non-winding column core of the previous transformer are the same core. The primary winding in each phase transformer is wound on the first winding column core in the phase transformer, and the secondary winding in each phase transformer is wound on the second winding column core in the phase transformer.
[0029] Figure 4 A schematic diagram of a dual active bridge converter provided in an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the present disclosure enables adjacent transformers to share the same non-winding column magnetic core, and the primary winding and the secondary winding in each phase transformer are wound separately to reduce the coupling between the primary winding and the secondary winding, increase the leakage inductance of the transformer, thereby replacing the energy storage inductor with the leakage inductance of the transformer to reduce the inductor magnetic core, and then significantly reduce the volume of the magnetic component. In addition, by using the transformer leakage inductance to replace the energy storage inductor, the inductor winding and the inductor magnetic core can also be reduced invisibly, which is conducive to reducing the winding loss and magnetic core loss of the converter.
[0030] In an exemplary embodiment, the first wound-leg magnetic core, the second wound-leg magnetic core, the first non-wound-leg magnetic core, and the second non-wound-leg magnetic core are all made of ferrite magnetic material.
[0031] In an exemplary embodiment, the material used for the primary winding and the secondary winding includes at least one of copper foil, copper wire, aluminum wire and paper insulation tape.
[0032] In an exemplary embodiment, Figure 1 A schematic structural diagram of a dual active bridge converter provided in an embodiment of the present disclosure. Figure 2 A side view of a dual active bridge converter provided in an embodiment of the present disclosure. Figure 3 A top view of a dual active bridge converter provided in an embodiment of the present disclosure.
[0033] like Figure 1 , Figure 2 and Figure 3As shown, the dual active bridge converter includes N phase transformers arranged and spliced in sequence, wherein N is a positive integer greater than 1. The first winding column magnetic core, the second winding column magnetic core, the first non-winding column magnetic core and the second non-winding column magnetic core in each phase transformer are all strip magnetic cores. The first winding column magnetic core, the first non-winding column magnetic core, the second winding column magnetic core and the second non-winding column magnetic core in each phase transformer are connected end to end to form a rectangular structure.
[0034] The first phase transformer includes a first winding column core 1, a second winding column core 2, a first non-winding column core (i.e., a yoke) 2*N+1, a second non-winding column core 2*N+2, and a primary winding Np1 and a secondary winding Ns1. The second phase transformer includes a first winding column core 3, a second winding column core 4, a first non-winding column core 2*N+2, a second non-winding column core 2*N+3, and a primary winding Np2 and a secondary winding Ns2. The Nth phase transformer includes a first winding column core 2*N-1, a second winding column core 2*N, a first non-winding column core 3*N, a second non-winding column core 3*N+1, and a primary winding Npn and a secondary winding Nsn, where n=1,2,3......,N.
[0035] The primary winding Np1 in the first phase transformer is wound on the first winding post core 1, and the secondary winding Ns1 in the first phase transformer is wound on the second winding post core 2. The primary winding Np2 in the second phase transformer is wound on the first winding post core 3, and the secondary winding Ns2 in the first phase transformer is wound on the second winding post core 4. The primary winding Npn in the Nth phase transformer is wound on the first winding post core 2*N-1, and the secondary winding Nsn in the first phase transformer is wound on the second winding post core 2*N.
[0036] In an exemplary embodiment, the winding directions of the primary winding and the secondary winding in the same phase transformer are consistent.
[0037] In an exemplary embodiment, all windings (including primary windings and secondary windings) in an N-phase transformer have the same winding direction, and the current phases between the windings differ by 360° / n in sequence.
[0038] For example, Figure 1As shown, the same-name end of the primary winding Np1 of the first-phase transformer is A1, the opposite-name end of the primary winding Np1 of the first-phase transformer is B1, the same-name end of the secondary winding Ns1 of the first-phase transformer is C1, and the opposite-name end of the secondary winding Ns1 of the first-phase transformer is D1. The same-name end of the primary winding Np2 of the second-phase transformer is A2, the opposite-name end of the primary winding Np2 of the second-phase transformer is B2, the same-name end of the secondary winding Ns2 of the second-phase transformer is C2, and the opposite-name end of the secondary winding Ns2 of the second-phase transformer is D2. The same-name end of the primary winding Npn of the N-phase transformer is An, the opposite-name end of the primary winding Npn of the N-phase transformer is Bn, the same-name end of the secondary winding Nsn of the N-phase transformer is Cn, and the opposite-name end of the secondary winding Nsn of the N-phase transformer is Dn. Among them, the same-name terminal refers to the current input terminal, and the opposite-name terminal refers to the current output terminal. That is, the winding direction of the primary winding and the secondary winding in the same phase transformer is consistent, and the winding direction of all windings in the N-phase transformer is the same.
[0039] In an exemplary embodiment, there is an air gap inside the first winding leg magnetic core and the second winding leg magnetic core in each phase transformer. Figure 1 As shown, the first winding post magnetic core 1 and the second winding post magnetic core 2 in the first phase transformer both have air gaps inside. The first winding post magnetic core 3 and the second winding post magnetic core 4 in the second phase transformer both have air gaps inside. The first winding post magnetic core 2*N-1 and the second winding post magnetic core 2*N in the N-th phase transformer both have air gaps inside, and the entire N-phase transformer has 2*N air gaps.
[0040] Figure 5 An analysis diagram of the first phase transformer of a dual active bridge converter and a distribution diagram of the magnetic field intensity in the core window provided in an embodiment of the present disclosure. Figure 6 A schematic diagram of an equivalent magnetic circuit of a dual active bridge converter provided in an embodiment of the present disclosure.
[0041] like Figure 5 As shown, one phase transformer in the N-phase transformer is analyzed. Figure 5 The dotted box in is a loop. According to Ampere's loop law:
[0042] Hl=NI (1)
[0043] Where H is the magnetic field strength, l is the magnetic path length, N is the number of coil turns, and I is the current.
[0044] According to Ampere's loop law, the field intensity distribution in the core window can be obtained, and then the expression of the magnetic field energy can be obtained. Specifically, the leakage magnetic field energy expression of the primary winding is:
[0045]
[0046] The expression of leakage magnetic field energy of the secondary winding is:
[0047]
[0048] The leakage magnetic field energy expression between the primary winding and the secondary winding is:
[0049]
[0050] l Np is the average winding length of the primary winding in the depth direction, l air is the average length of the original secondary edge spacing in the depth direction, l Ns is the average winding length of the secondary winding in the depth direction. The height of the secondary winding in the core window is a, the height of the primary winding in the core window is c, and the spacing between the primary winding and the secondary winding is b. The width of the core window is lw, μ0 is the air permeability, Np is the number of turns of the primary winding, Ip is the current of the primary winding, Ns is the number of turns of the secondary winding, and Is is the current of the secondary winding.
[0051] The leakage magnetic field energy W in the core window m for:
[0052] W m =W p +W s +W air (5)
[0053] Due to the leakage magnetic field energy W in the core window m Equal to the leakage inductance energy W lk :
[0054]
[0055] Calculate the leakage inductance L k The expression is:
[0056]
[0057] According to Expression 7 and Figure 5 It can be seen that the primary winding and the secondary winding of the same phase transformer are wound on different winding pole cores. Since the magnetic field strength between the primary winding and the secondary winding is the largest, the magnetic field energy of the distance between the primary winding and the secondary winding can be increased by increasing the distance between the primary winding and the secondary winding, thereby increasing the leakage inductance stored in the air, so that the leakage inductance of the transformer replaces the energy storage inductance. Figure 6As shown in the figure, the winding direction of the primary winding and the secondary winding of the N-phase transformer is consistent. According to the right-hand screw rule, the winding direction of the magnetic flux is the same. The magnetic flux in the same phase transformer cancels each other, and the magnetic flux between the transformer phases flows to the low magnetic resistance (i.e. the magnetic resistance of the winding column Rm2), forming a loop flow to achieve a decoupling effect. At this point, the N-phase transformer and N inductors are magnetically integrated.
[0058] like Figure 6 As shown, the magnetic resistance of the side column is Rm1, the magnetic resistance of the winding column is Rm2, and the magnetic resistance of the decoupling column is Rm3, where Φ1 is the first phase magnetic flux, Φ2 is the second phase magnetic flux, Φ3 is the third phase magnetic flux, and ΦN is the Nth phase magnetic flux. The decoupling between phases forms a high magnetic resistance through the air gap on the winding column, and the side column has no air gap to form a low magnetic resistance. The magnetic flux generated by the primary winding Np1 will not flow through the primary winding Np2, the secondary winding Ns2, the primary winding Np3, the secondary winding Ns3, ..., the primary winding Npn, and the secondary winding Nsn. Similarly, the magnetic flux generated by the secondary winding Ns1 will not flow through the primary winding Np2, the secondary winding Ns2, the primary winding Np3, the secondary winding Ns3, ..., the primary winding Npn, and the secondary winding Nsn. By analogy, decoupling is formed between phases.
[0059] In one embodiment, the present disclosure provides a bidirectional DC conversion module, including the aforementioned dual active bridge converter.
[0060] In one embodiment, the present disclosure provides a power supply device, including an input end, a voltage converter and an output end, wherein the voltage converter is the aforementioned bidirectional DC conversion module.
[0061] The dual active bridge converter provided in this embodiment reduces the coupling between the primary winding and the secondary winding in the transformer by making adjacent transformers share the same non-winding column magnetic core and winding the primary winding and the secondary winding in each phase transformer separately, increases the leakage inductance of the transformer, and realizes the work of replacing the energy storage inductor with the leakage inductance of the transformer, thereby reducing the inductor magnetic core, and then significantly reducing the volume and weight of the magnetic component. In addition, by using the leakage inductance of the transformer to replace the energy storage inductor, the inductor winding and the inductor magnetic core can be reduced invisibly, which is conducive to reducing the winding loss and magnetic core loss of the converter. And when the transformer is wound, the winding direction of the primary winding and the secondary winding is consistent, and the magnetic flux forms a canceling effect. In particular, on the middle column of the two non-winding column magnetic cores, the magnetic flux between the phases is a canceling effect here. Therefore, the N-phase transformer forms a good decoupling effect.
[0062] Although the embodiments disclosed in the present disclosure are as above, the above contents are only embodiments adopted for facilitating the understanding of the present disclosure and are not intended to limit the present disclosure. Any technician in the technical field to which the present disclosure belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present disclosure, but the scope of patent protection of the present disclosure shall still be subject to the scope defined in the attached claims.
Claims
1. A dual active bridge converter, characterized in that: It includes a multi-phase transformer that is sequentially arranged and spliced, and each phase transformer includes a first winding column magnetic core, a second winding column magnetic core, a first non-winding column magnetic core, a second non-winding column magnetic core, a primary winding and a secondary winding; Among them, the first winding column core, the first non-winding column core, the second winding column core and the second non-winding column core in each phase transformer are connected end to end, and the positions of the first winding column core and the second winding column core are opposite. In two adjacent transformers, the first non-winding column core of the latter transformer and the second non-winding column core of the previous transformer are the same core. The primary winding in each phase transformer is wound on the first winding column core in the phase transformer, and the secondary winding in each phase transformer is wound on the second winding column core in the phase transformer.
2. The dual active bridge converter according to claim 1, characterized in that: The winding direction of the primary winding and the secondary winding in the same phase transformer is the same.
3. The dual active bridge converter according to claim 1, characterized in that: There is an air gap inside the first winding leg magnetic core and the second winding leg magnetic core in each phase transformer.
4. The dual active bridge converter according to claim 2, characterized in that: The winding direction of the primary and secondary windings in all phase transformers is the same.
5. The dual active bridge converter according to claim 1, characterized in that: The first winding column magnetic core, the second winding column magnetic core, the first non-winding column magnetic core and the second non-winding column magnetic core in each phase of the transformer are all bar-shaped magnetic cores.
6. The dual active bridge converter according to claim 5, characterized in that: The first winding column magnetic core, the first non-winding column magnetic core, the second winding column magnetic core and the second non-winding column magnetic core in each phase transformer are connected end to end to form a rectangular structure.
7. The dual active bridge converter according to claim 1, characterized in that: The material used for the primary winding and the secondary winding includes at least one of copper foil, copper wire, aluminum wire and paper insulating tape.
8. The dual active bridge converter according to claim 1, characterized in that: The first winding column magnetic core, the second winding column magnetic core, the first non-winding column magnetic core and the second non-winding column magnetic core are all made of ferrite magnetic material.
9. A bidirectional DC conversion module, characterized in that: It comprises the dual active bridge converter as claimed in any one of claims 1 to 8.
10. A power supply device, characterized in that: It comprises an input end, a voltage converter and an output end, wherein the voltage converter is a bidirectional DC conversion module as claimed in claim 9.