Inductor and power converter

Abstract

The embodiment of the utility model provides an inductor and a power converter comprising the inductor, and relates to the technical field of inductors. The inductor comprises a first magnetic core, a second magnetic core, a third magnetic core, a first winding and a second winding, the third magnetic core is located between the first magnetic core and the second magnetic core, and the magnetic conductivity of the first magnetic core and the magnetic conductivity of the second magnetic core are both larger than that of the third magnetic core; the first magnetic core and the third magnetic core define at least one first winding hole, and the first winding is wound on the first magnetic core; the second magnetic core and the third magnetic core encircle at least one second winding hole, and the second winding is wound on the second magnetic core.

Description

Technical Field

[0001] The present application relates to the technical field of inductors, and in particular to an inductor and a power converter. Background Art

[0002] The DC / DC converter uses the energy storage characteristics of the inductor to perform high-frequency switching through a controllable switch, storing the input electrical energy in the inductor. When the switch is disconnected, the electrical energy is released to the load to provide energy, which can be used for voltage boosting and voltage reduction.

[0003] Some high-power DC / DC converters usually use parallel technology, that is, multiple groups of DC / DC circuits work in parallel, where each group of DC / DC circuits contains an inductor, and each inductor works independently. When the number of DC / DC circuits in parallel is large, the number of inductors will also increase, resulting in higher equipment costs. Multiple inductors will also occupy a larger space, which is not conducive to reducing the size of the equipment, and the power density will also decrease. Utility Model Content

[0004] The present application provides an inductor and a power converter including the inductor, which can reduce the volume of the inductor, thereby reducing the volume of the power converter and improving the power density of the power converter.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect of the present application, an inductor is provided, which includes a first magnetic core, a second magnetic core and a third magnetic core, and a first winding and a second winding; the third magnetic core is located between the first magnetic core and the second magnetic core, and the magnetic permeability of the first magnetic core and the magnetic permeability of the second magnetic core are both greater than the magnetic permeability of the third magnetic core; the first winding is wound on the first magnetic core, and the second winding is wound on the second magnetic core.

[0007] The inductor of the present application is wound with at least two windings (a first winding and a second winding), and one inductor can realize the functions of at least two inductors. The third magnetic core is shared by the first magnetic core and the second magnetic core, which reduces the volume of the inductor and the area occupied by the board (circuit board), and can also reduce the manufacturing cost of the inductor. Since the magnetic permeability of the third magnetic core is relatively low (larger magnetic resistance), and the magnetic permeability of the first magnetic core and the second magnetic core is relatively high (smaller magnetic resistance), the magnetic flux is more likely to pass through the first magnetic core and the second magnetic core, and the third magnetic core is not easy to saturate. In this way, the volume of the third magnetic core can be made smaller. For example, the manufactured third magnetic core can be thinner or thinner, so that the distance between the first magnetic core and the second magnetic core is reduced, further reducing the volume of the inductor.

[0008] In addition, when the first winding and the second winding are loaded with current respectively, the direction of the current flow and the winding direction of the winding will affect the path of the magnetic flux. In one case, part of the magnetic flux generated by the first winding and part of the magnetic flux generated by the second winding cancel each other out on the first magnetic core and the second magnetic core. Since the magnetic flux is easier to flow through the first magnetic core and the second magnetic core, more magnetic flux cancels out on the first magnetic core and the second magnetic core, thereby reducing the peak-to-peak value of the inductor current, reducing the change in magnetic flux density, reducing the power loss on the inductor, and also reducing the power loss on some devices in the circuit, for example, reducing the power loss on the circuit switch device. In another case, the magnetic flux generated by the first winding and the magnetic flux generated by the second winding cancel each other out on the third magnetic core, making the magnetic flux of the third magnetic core smaller, making the third magnetic core less likely to saturate, and further reducing the volume of the third magnetic core.

[0009] By using the inductor of the present application, the path of the magnetic flux can be adjusted by adjusting the direction of current flow or the winding method of the first winding and the second winding (that is, adjusting which magnetic core the magnetic flux cancels and which magnetic core it superimposes), so as to obtain the desired effect. This can correspond to different product requirements, making the inductor of the present application more flexible in application and production.

[0010] In one embodiment of the present application, the first magnetic core includes a first magnetic column and a plurality of second magnetic columns, the first magnetic column extends along a first direction, the first magnetic column and the third magnetic core are arranged in a second direction, the first direction intersects with the second direction, and the plurality of second magnetic columns are arranged between the first magnetic column and the third magnetic core at intervals along the first direction, and each second magnetic column is connected to the first magnetic column.

[0011] The first magnetic column and the plurality of second magnetic columns form a first magnetic core, the first winding can be wound on the first magnetic column or the second magnetic column, and the space between two adjacent second magnetic columns is for the first winding to pass through. The first magnetic core composed of the first magnetic column and the second magnetic column according to the above design method, after being spliced ​​with the third magnetic core, is conducive to the flow of magnetic flux, so that the magnetic flux can form a loop on the first magnetic core and the third magnetic core, realizing a closed magnetic circuit.

[0012] In an embodiment of the present application, one end of each second magnetic column facing away from the first magnetic column is in contact with the third magnetic core.

[0013] Each second magnetic column is in contact with the third magnetic core, that is, there is no air gap between the second magnetic column and the third magnetic core, so that the magnetic resistance between the first magnetic core and the third magnetic core is reduced, which is conducive to the flow of magnetic flux between the first magnetic core and the third magnetic core, and is particularly conducive to the smooth flow of magnetic flux between the first magnetic core and the second magnetic core (because the magnetic flux needs to pass through the third magnetic core before flowing to the second magnetic core). For example, in the case where part of the magnetic flux generated by the first winding and part of the magnetic flux generated by the second winding cancel each other out on the first magnetic core and the second magnetic core, the lower magnetic resistance between the magnetic cores makes it easier for the magnetic flux to flow through the first magnetic core and the second magnetic core, and more magnetic flux can be canceled out on the first magnetic core and the second magnetic core, increasing the coupling between the first winding and the second winding, thereby reducing the peak-to-peak value of the inductor current and reducing the loss of the device.

[0014] In one embodiment of the present application, the second magnetic core includes a third magnetic column and a plurality of fourth magnetic columns, the third magnetic column extends along the first direction, the third magnetic column and the third magnetic core are arranged in the second direction, the plurality of fourth magnetic columns are distributed between the third magnetic column and the third magnetic core at intervals along the first direction, and each fourth magnetic column is connected to the third magnetic column.

[0015] The third magnetic column and a plurality of fourth magnetic columns form a second magnetic core, the second winding can be wound on the third magnetic column or the fourth magnetic column, and the space between two adjacent fourth magnetic columns is for the second winding to pass through. The second magnetic core composed of the third magnetic column and the fourth magnetic column according to the above design method, after being spliced ​​with the third magnetic core, is conducive to the flow of magnetic flux, so that the magnetic flux can form a loop, and realize a closed magnetic circuit.

[0016] In an embodiment of the present application, one end of each fourth magnetic column facing away from the third magnetic column is in contact with the third magnetic core.

[0017] Each fourth magnetic column is in contact with the third magnetic core, that is, on the basis that there is no air gap between the second magnetic column and the third magnetic core, there is no air gap between the fourth magnetic column and the third magnetic column, so that the magnetic resistance between the first magnetic core and the third magnetic core and the magnetic resistance between the second magnetic core and the third magnetic core are both small, and the magnetic flux is easier to flow between the first magnetic core and the second magnetic core. In the case where part of the magnetic flux generated by the first winding and part of the magnetic flux generated by the second winding cancel each other on the first magnetic core and the second magnetic core, more magnetic flux can be canceled on the first magnetic core and the second magnetic core, thereby reducing the peak-to-peak value of the inductor current and reducing the loss of the device.

[0018] In an embodiment of the present application, the number of the second magnetic pillars is the same as the number of the fourth magnetic pillars, and the plurality of second magnetic pillars and the plurality of fourth magnetic pillars are arranged on both sides of the third magnetic core in a one-to-one correspondence.

[0019] Multiple second magnetic columns and multiple fourth magnetic columns are arranged on both sides of the third magnetic core in a one-to-one correspondence. The magnetic flux can flow from the second magnetic column to the corresponding fourth magnetic column, and the magnetic flux can also flow from the fourth magnetic column to the corresponding second magnetic column, which is beneficial for the magnetic flux to flow between the first magnetic core and the second magnetic core, and also beneficial for the magnetic flux to form a loop.

[0020] In one embodiment of the present application, the multiple second magnetic columns include three second magnetic columns, the first winding is wound around one of the three second magnetic columns located in the middle, the multiple fourth magnetic columns include three fourth magnetic columns, and the second winding is wound around one of the three fourth magnetic columns located in the middle.

[0021] The first magnetic column and the three second magnetic columns form an E-type magnetic core, and the third magnetic column and the three fourth magnetic columns form an E-type magnetic core. The E-type magnetic core is relatively simple in terms of winding and assembly, has good heat dissipation effect, and can be used in a stacked manner. It is a widely used magnetic core. In addition, the E-type magnetic core is also easy to obtain, which reduces the production cost of the inductor. Through the above design method, the first magnetic core, the second magnetic core and the third magnetic core form an EIE-type inductor magnetic core, which is conducive to the assembly between the first magnetic core, the second magnetic core and the third magnetic core, and also facilitates the installation of the inductor on the equipment in the later stage.

[0022] In one embodiment of the present application, the third magnetic core has a first side and a second side back to back in the third direction, the first direction and the second direction are both perpendicular to the third direction, and both ends of the first winding and the second winding extend to the first side.

[0023] The first side and the second side are the two sides of the third magnetic core back to back, and are also the two sides of the first magnetic core and the two sides of the second magnetic core. The inductor needs to be installed on the circuit board. When installing the inductor, the circuit board can be located on the first side of the multiple magnetic cores, and both ends of the first winding and the second winding can be extended to the first side. Then, both ends of the first winding and the second winding are connected to the circuit board to complete the installation of the inductor.

[0024] According to a second aspect of the present application, a power converter is provided. The power converter includes an inductor and a plurality of bridge arms. The first winding and the second winding are each connected to at least one bridge arm.

[0025] The third magnetic core is shared by the first magnetic core and the second magnetic core, which reduces the volume of the inductor and the board (circuit board) area, and can also reduce the manufacturing cost of the inductor, thereby reducing the volume and cost of the power converter. When the partial magnetic flux generated by the first winding and the partial magnetic flux generated by the second winding cancel each other on the first magnetic core and the second magnetic core, the peak-to-peak value of the inductor current can be reduced, the loss of the inductor can be reduced, and the loss of some devices electrically connected to the inductor can be reduced, so that the efficiency of the power converter is improved. When the partial magnetic flux generated by the first winding and the partial magnetic flux generated by the second winding cancel each other on the third magnetic core, the third magnetic core is less likely to saturate, and the volume of the third magnetic core can be further reduced, making the volume of the inductor smaller, thereby further reducing the volume of the power converter.

[0026] In one embodiment of the present application, the end of the first winding that is closer to the third magnetic core is the current input end of the first winding, and the end of the second winding that is closer to the third magnetic core is the current input end of the second winding; or, the end of the first winding that is farther from the third magnetic core is the current input end of the first winding, and the end of the second winding that is farther from the third magnetic core is the current input end of the second winding.

[0027] The current input end of the first winding and the current input end of the second winding are both close to the third magnetic core, or are both far away from the third magnetic core, which is more in line with the design of the circuit board, is conducive to the layout and wiring of the circuit board, and is also convenient for connecting the two ends of the first winding and the two ends of the second winding to the circuit board.

[0028] In one embodiment of the present application, the winding direction of the first winding from one end closer to the third magnetic core to the other end is opposite to the winding direction of the second winding from one end closer to the third magnetic core to the other end.

[0029] According to the winding method of the first winding and the second winding, when the first winding and the second winding are respectively loaded with current, part of the magnetic flux generated by the first winding and part of the magnetic flux generated by the second winding will cancel each other out on the first magnetic core and the second magnetic core. Since the magnetic permeability of the first magnetic core and the second magnetic core is relatively large, the magnetic flux is more likely to flow through the first magnetic core and the second magnetic core, which makes more magnetic flux cancel out on the first magnetic core and the second magnetic core, thereby reducing the peak-to-peak value of the inductor current, reducing the power loss on the inductor, and also reducing the power loss on some devices in the circuit, for example, reducing the power loss when the switch device in the circuit is turned off. In addition, the magnetic flux of the first magnetic core and the second magnetic core is reduced, which also makes the first magnetic core and the second magnetic core less likely to saturate. The volume of the first magnetic core and the second magnetic core can be reduced during design and manufacturing, and the volume of the inductor is further reduced, which further reduces the volume of the power converter.

[0030] In one embodiment of the present application, the winding direction of the first winding from one end closer to the third magnetic core to the other end is the same as the winding direction of the second winding from one end closer to the third magnetic core to the other end.

[0031] According to the winding method of the first winding and the second winding, when the first winding and the second winding are respectively loaded with current, part of the magnetic flux generated by the first winding and part of the magnetic flux generated by the second winding cancel each other out on the third magnetic core, making the magnetic flux of the third magnetic core smaller and the third magnetic core less likely to saturate (the third magnetic core has a low magnetic permeability and is not likely to saturate in the first place). In this way, the volume of the third magnetic core can be further reduced during design and manufacturing, thereby reducing the volume of the entire inductor.

[0032] The power converter provided in the present application includes the above-mentioned inductor, so the power converter provided in the present application and the inductor of the above-mentioned technical solution can solve the same technical problem and have the same technical effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a power converter provided in an embodiment of the present application;

[0034] Figure 2 An H-bridge circuit diagram of a power converter provided in an embodiment of the present application;

[0035] Figure 3 A power factor correction circuit diagram of a power converter provided in an embodiment of the present application;

[0036] Figure 4 A schematic diagram of a partial structure of a power converter provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of a partial structure of an inductor provided in an embodiment of the present application;

[0038] Figure 6 A schematic diagram of the structure of the first magnetic core, the second magnetic core and the third magnetic core provided in an embodiment of the present application;

[0039] Figure 7 A diagram of a winding method of a first winding and a second winding provided in an embodiment of the present application;

[0040] Figure 8 A diagram of the variation of the inductor current provided in an embodiment of the present application;

[0041] Fig. 9 A diagram of another winding method for the first winding and the second winding provided in an embodiment of the present application.

[0042] Reference numerals:

[0043] 100-power converter;

[0044] 110-circuit board;

[0045] 120-Inductor;

[0046] 1-first magnetic core; 10-first winding hole; 11-first magnetic column; 12-second magnetic column;

[0047] 2-second magnetic core; 20-second winding hole; 21-third magnetic column; 22-fourth magnetic column;

[0048] 3-third magnetic core; 31-first side; 32-second side;

[0049] 4-First winding;

[0050] 5- Second winding;

[0051] 6-Mounting seat. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0053] In this application, the terms "first", "second", etc. are used only for descriptive purposes to distinguish one element from another element, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0054] In the present application, unless otherwise clearly specified or limited, "plurality" means two or more.

[0055] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] In the present application, unless otherwise clearly specified and limited, the term "coupling" should be understood in a broad sense. For example, "coupling" can be a direct electrical connection between two components, for example, two components are physically in contact and electrically conductive, and can also be understood as different components in a circuit structure being electrically connected through physical lines such as printed circuit board (PCB) copper foil or wires that can transmit electrical signals to transmit electrical signals; or, "coupling" can be an indirect electrical connection between two components through an intermediate medium; or, "coupling" can be an electrical connection between two components in an air / non-contact manner, for example, two components are electrically connected by capacitive coupling, inductive coupling or resistive coupling to transmit electrical signals.

[0057] In addition, in this application, the words "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0058] In the drawings of the embodiments of the present application, solid structures such as components and assemblies are represented by guide lines; hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with arrows.

[0059] A power converter 100 provided in an embodiment of the present application, for example, a DC / DC converter, can be used as a communication power supply of an energy storage device (or used in other scenarios, which is not specifically limited in the present application). Figure 1 , Figure 1 The structure of the power converter 100 is exemplarily shown. A circuit board 110 is arranged inside the power converter 100. A circuit for boosting or reducing voltage is arranged on the circuit board 110. The circuit includes a plurality of bridge arms.

[0060] For example, a staggered parallel dual H-bridge circuit is provided on the circuit board 110. Figure 2 An exemplary staggered parallel dual H-bridge circuit is shown. In one H-bridge circuit, the first bridge arm B1 is provided with a switch tube Q1 and a switch tube Q2 connected in series, and the second bridge arm B2 is provided with a switch tube Q3 and a switch tube Q4 connected in series. In another H-bridge circuit, the third bridge arm B3 is provided with a switch tube Q5 and a switch tube Q6 connected in series, and the fourth bridge arm B4 is provided with a switch tube Q7 and a switch tube Q8 connected in series. The two H-bridge circuits are connected in parallel.

[0061] In the above circuit, in Buck mode, Q1 and Q2 are complementary turned on (Q2 is off when Q1 is on, and Q1 is off when Q2 is on), Q5 and Q6 are complementary turned on, Q3 and Q7 are always on, and Q4 and Q8 are always off. In Boost mode, Q1 and Q5 are always on, Q2 and Q6 are always off, Q3 and Q4 are complementary turned on, and Q7 and Q8 are complementary turned on.

[0062] For another example, the circuit board 110 is provided with a staggered parallel power factor correction (PFC) circuit. Figure 3 An exemplary power factor correction circuit is shown. Arrow A indicates a rectifier bridge, and a boost diode D1 and a switch tube Q9 connected in series are provided on the fifth bridge arm B5, and a boost diode D2 and a switch tube Q10 connected in series are provided on the sixth bridge arm B6. The fifth bridge arm B5 and the sixth bridge arm B6 are connected in parallel.

[0063] The switch tube mentioned above can be a MOS tube, where the full name of MOS tube is Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), which is a commonly used semiconductor device. By controlling the duty cycle (the ratio of the time of opening and closing) of the MOS tube through the chip, the output can be boosted or bucked.

[0064] In order to achieve energy storage and release, return to reference Figure 1 The power converter 100 of the present application may further include an inductor 120, which is disposed on the circuit board 110. The inductor 120 is an electronic component that mainly converts current into magnetic field energy and releases it when needed, thereby realizing the conversion and transmission of electrical energy in the circuit.

[0065] Reference Figure 2 and Figure 3 The present application provides an inductor 120. The exemplary inductor 120 includes a plurality of windings. The plurality of windings may include a first winding 4 and a second winding 5. The first winding 4 and the second winding 5 are each connected to at least one bridge arm.

[0066] exist Figure 2 In the circuit shown, one end of the first winding 4 is connected to the first bridge arm B1, and the other end of the first winding 4 is connected to the second bridge arm B2; one end of the second winding 5 is connected to the third bridge arm B3, and the other end of the second winding 5 is connected to the fourth bridge arm B4. By controlling multiple switch tubes (Q1, Q2...Q7, Q8), a phase difference exists between the inductor currents of the two H-bridge circuits, for example, the phase difference between the inductor currents of the two H-bridge circuits is 180°.

[0067] exist Figure 3 In the circuit shown, one end of the first winding 4 is connected to the fifth bridge arm B5, and one end of the second winding 5 is connected to the sixth bridge arm B6. By controlling the switch tube Q9 and the switch tube Q10, a phase difference exists between the two-phase inductor current (the inductor current of the first winding 4 and the inductor current of the second winding 5), for example, a phase difference of 180° is made between the two-phase inductor current.

[0068] Reference Figure 4 , Figure 4 The structure of the inductor 120 is shown as an example. The inductor 120 also includes multiple magnetic cores, which include a first magnetic core 1, a second magnetic core 2 and a third magnetic core 3. The third magnetic core 3 is located between the first magnetic core 1 and the second magnetic core 2. The first winding 4 is wound on the first magnetic core 1, and the second winding 5 is wound on the second magnetic core 2. Both ends of the first winding 4 and both ends of the second winding 5 are connected to the circuit board 110 (for example, welded).

[0069] The inductor 120 of the present application has a first direction, a second direction and a third direction, referring to Figure 4 , the third direction may be a direction perpendicular to the surface of the circuit board 110, the first direction and the second direction are both perpendicular to the third direction, that is, the first direction and the second direction may both be parallel to the surface of the circuit board 110. The first magnetic core 1, the second magnetic core 2 and the third magnetic core 3 may be distributed along the second direction, and the first direction intersects the second direction. Figure 4 In the example provided, the first direction is perpendicular to the second direction, that is, the first direction, the second direction and the third direction are perpendicular to each other. In other examples, the first direction and the second direction may only intersect but not be perpendicular.

[0070] Reference Figure 5 , Figure 5 The partial structure of the inductor 120 is shown as an example, the first magnetic core 1 and the third magnetic core 3 surround at least one first winding hole 10, and the first winding 4 will pass through the at least one first winding hole 10 after winding; the second magnetic core 2 and the third magnetic core 3 surround at least one second winding hole 20, and the second winding 5 will pass through the at least one second winding hole 20 after winding. That is, the first magnetic core 1 and the second magnetic core 2 share the third magnetic core 3, which can reduce the volume and board area of ​​the inductor 120.

[0071] Furthermore, in the present application, one inductor 120 can realize the functions of at least two inductors 120 , thereby reducing the manufacturing cost of the inductor 120 .

[0072] In addition, the magnetic permeability of the first magnetic core 1 and the magnetic permeability of the second magnetic core 2 are both greater than the magnetic permeability of the third magnetic core 3. For example, the magnetic permeability of the first magnetic core 1 and the magnetic permeability of the second magnetic core 2 are the same, and the magnetic permeability of the first magnetic core 1 and the magnetic permeability of the second magnetic core 2 are both greater than the magnetic permeability of the third magnetic core 3. For another example, the magnetic permeability of the first magnetic core 1 and the magnetic permeability of the second magnetic core 2 are different, but the magnetic permeability of the first magnetic core 1 and the magnetic permeability of the second magnetic core 2 are both greater than the magnetic permeability of the third magnetic core 3.

[0073] The magnetic permeability of the magnetic core can be adjusted by adjusting the proportion of metals constituting the magnetic core, and this application does not impose any specific restrictions on this.

[0074] Since the magnetic permeability of the third magnetic core 3 is low (magnetic resistance is large), and the magnetic permeability of the first magnetic core 1 and the second magnetic core 2 is high (magnetic resistance is small), when the current is loaded, the magnetic flux is more likely to pass through the first magnetic core 1 and the second magnetic core 2, and the third magnetic core 3 is not easy to saturate, so that the volume of the third magnetic core 3 can be manufactured smaller. For example, the size of the manufactured third magnetic core 3 in the distribution direction of the first magnetic core 1 and the second magnetic core 2 (the second direction in the figure) is small, so that the third magnetic core 3 is thinner or thinner, which reduces the distance between the first magnetic core 1 and the second magnetic core 2, further reduces the volume of the inductor 120, and also reduces the volume of the power converter 100.

[0075] The first magnetic core 1 may have various structures. In one example, refer to Figure 6 , Figure 6 The structure of a first magnetic core 1 is shown as an example. The first magnetic core 1 may include a first magnetic column 11 and a plurality of second magnetic columns 12 (there are three second magnetic columns 12 in the attached figure). The first magnetic column 11 extends along a first direction. The first magnetic column 11 and the third magnetic core 3 are distributed in a second direction (in the example provided in the attached figure, the first direction is perpendicular to the second direction). The plurality of second magnetic columns 12 are arranged between the first magnetic column 11 and the third magnetic core 3 at intervals along the first direction. Each second magnetic column 12 is connected to the first magnetic column 11, and a first winding hole 10 is formed between two adjacent second magnetic columns 12. After the first magnetic column 11 and the plurality of second magnetic columns 12 form the first magnetic core 1, they are spliced ​​with the third magnetic core 3, which is conducive to the flow of magnetic flux, so that the magnetic flux can form a loop between the first magnetic core 1 and the third magnetic core 3, and realize a closed magnetic circuit.

[0076] The number of the second magnetic columns 12 can be set as required. For example, three second magnetic columns 12 can be provided, and two first winding holes 10 are formed, that is, the first magnetic core 1 is an E-type magnetic core. For another example, two or four second magnetic columns 12 can also be provided.

[0077] The second magnetic core 2 may have various structures. In one example, refer to Figure 6The second magnetic core 2 may include a third magnetic column 21 and a plurality of fourth magnetic columns 22 (there are three fourth magnetic columns 22 in the attached figure), the third magnetic column 21 extends along the first direction, the third magnetic column 21 and the third magnetic core 3 are distributed in the second direction, and the plurality of fourth magnetic columns 22 are arranged between the third magnetic column 21 and the third magnetic core 3 at intervals along the first direction, each fourth magnetic column 22 is connected to the third magnetic column 21, and a second winding hole 20 is formed between two adjacent fourth magnetic columns 22. After the third magnetic column 21 and the plurality of fourth magnetic columns 22 form the second magnetic core 2, they are spliced ​​with the third magnetic core 3, which is conducive to the flow of magnetic flux, so that the magnetic flux can form a loop, and realize a closed magnetic circuit.

[0078] The number of the fourth magnetic columns 22 can be set as required. For example, three fourth magnetic columns 22 can be provided, and two second winding holes 20 are formed, that is, the second magnetic core 2 is an E-type magnetic core. For another example, two or four fourth magnetic columns 22 can also be provided.

[0079] The number of the second magnetic pillars 12 and the number of the fourth magnetic pillars 22 may be the same, and the plurality of second magnetic pillars 12 and the plurality of fourth magnetic pillars 22 are arranged one by one on both sides of the third magnetic core 3. The magnetic flux may flow from the second magnetic pillar 12 to the corresponding fourth magnetic pillar 22, and the magnetic flux may also flow from the fourth magnetic pillar 22 to the corresponding second magnetic pillar 12, which is conducive to the flow of magnetic flux between the first magnetic core 1, the second magnetic core 2 and the third magnetic core 3.

[0080] For example, three second magnetic columns 12 are provided, three fourth magnetic columns 22 are provided, and each second magnetic column 12 and one fourth magnetic column 22 are correspondingly provided on both sides of the third magnetic core 3. The first magnetic core 1 and the second magnetic core 2 are both E-type magnetic cores, which are relatively simple in winding and assembly, have good heat dissipation effect, and can be used in a stacked manner. They are widely used magnetic cores, are easy to obtain, and reduce the manufacturing cost of the inductor 120.

[0081] In other examples, two second magnetic pillars 12 and two fourth magnetic pillars 22 may be provided respectively. The two second magnetic pillars 12 are respectively provided at both ends of the first magnetic pillar 11, and the two fourth magnetic pillars 22 are respectively provided at both ends of the third magnetic pillar 21, that is, the first magnetic core 1 and the second magnetic core 2 are both C-shaped magnetic cores.

[0082] The third magnetic core 3 can be constructed in any suitable structure, for example, Figure 6 The third magnetic core 3 is a flat rectangular magnetic core bar, and the thickness direction of the third magnetic core 3 is parallel to the distribution direction of the first magnetic core 1 and the second magnetic core 2. Since the magnetic permeability of the third magnetic core 3 is small, the magnetic resistance of the third magnetic core 3 is low, and the third magnetic core 3 is not easy to saturate, the size of the third magnetic core 3 in the thickness direction can be designed to be very small, that is, the manufactured third magnetic core 3 can be thinner, thereby reducing the volume of the inductor 120.

[0083] The extension direction of the first magnetic column 11 and the extension direction of the third magnetic column 21 can be parallel to the extension direction of the third magnetic core 3, that is, the first magnetic column 11, the third magnetic column 21 and the third magnetic core 3 all extend along the first direction, and the extension direction of each second magnetic column 12 and the extension direction of each fourth magnetic column 22 can be perpendicular to the extension direction of the third magnetic core 3.

[0084] In some examples, the third magnetic core 3 can be called an I-type magnetic core. In the example where the first magnetic core 1 and the second magnetic core 2 are E-type magnetic cores, the first magnetic core 1, the second magnetic core 2 and the third magnetic core 3 form an EIE-type inductor core, which facilitates the assembly of the first magnetic core 1, the second magnetic core 2 and the third magnetic core 3, and also facilitates the assembly of the inductor 120.

[0085] To reduce magnetic resistance, refer to Figure 6 , each second magnetic column 12 is in contact with the third magnetic core 3, and each fourth magnetic column 22 is in contact with the third magnetic core 3. That is, there is no air gap between the second magnetic column 12 and the third magnetic core 3, and there is no air gap between the fourth magnetic column 22 and the third magnetic core 3, so that the magnetic flux generated by the first winding 4 and the second winding 5 can flow smoothly between the first magnetic core 1, the second magnetic core 2 and the third magnetic core 3.

[0086] The first winding 4 can be wound at any suitable position on the first magnetic core 1 . In the example where the first magnetic core 1 includes a first magnetic column 11 and a plurality of second magnetic columns 12 , the first winding 4 can be wound on the first magnetic column 11 or on one of the second magnetic columns 12 .

[0087] In the example where the first magnetic core 1 is an E-type magnetic core, refer to Figure 5 , the first winding 4 is wound on the middle second magnetic column 12 among the three second magnetic columns 12. In this example, the magnetic flux of the middle second magnetic column 12 is large, and the magnetic flux of the second magnetic columns 12 on both sides is small. Therefore, the cross-sectional area of ​​the middle second magnetic column 12 is larger than the cross-sectional area of ​​the second magnetic columns 12 on either side. For example, the cross-sectional area of ​​the middle second magnetic column 12 is equal to the sum of the cross-sectional areas of the other two second magnetic columns 12.

[0088] Similarly, the second winding 5 can be wound at any suitable position on the second magnetic core 2. In the example where the second magnetic core 2 includes a third magnetic column 21 and multiple fourth magnetic columns 22, the second winding 5 can be wound on the third magnetic column 21 or on one of the fourth magnetic columns 22.

[0089] In the example where the first magnetic core 1 is an E-type magnetic core, refer to Figure 5, the second winding 5 is wound on the fourth magnetic column 22 located in the middle among the three fourth magnetic columns 22. In this example, the magnetic flux of the fourth magnetic column 22 located in the middle is large, and the magnetic flux of the fourth magnetic columns 22 on both sides is small. Therefore, the cross-sectional area of ​​the fourth magnetic column 22 located in the middle is larger than the cross-sectional area of ​​the fourth magnetic column 22 on either side. For example, the cross-sectional area of ​​the fourth magnetic column 22 in the middle is equal to the sum of the cross-sectional areas of the other two fourth magnetic columns 22.

[0090] In order to facilitate the connection of multiple windings and the circuit board 110, both ends of the first winding 4 and the second winding 5 can be extended from one side of the inductor 120. Figure 4 The third magnetic core 3 has a first side 31 and a second side 32 which are back-to-back in the third direction, the first winding hole 10 is connected to the first side 31 and the second side 32, and the second winding hole 20 is also connected to the first side 31 and the second side 32. It can be understood that the first side 31 is a side of the third magnetic core 3 close to the circuit board 110, the second side 32 is a side of the third magnetic core 3 away from the circuit board 110, the first side 31 and the second side 32 are also two sides of the first magnetic core 1, and the first side 31 and the second side 32 are also two sides of the second magnetic core 2.

[0091] Reference Figure 4 When the first magnetic core 1, the second magnetic core 2 and the third magnetic core 3 are assembled, both ends of the first winding 4 and both ends of the second winding 5 extend to the first side 31, that is, extend to the side of the inductor 120 close to the circuit board 110, so as to facilitate the connection between the first winding 4 and the second winding 5 and the circuit board 110.

[0092] In addition, the inductor 120 may further include a mounting base 6, which is disposed on the first side 31, and the first magnetic core 1, the second magnetic core 2, and the third magnetic core 3 are mounted on the mounting base 6, or in other words, the mounting base 6 is disposed between the plurality of magnetic cores and the circuit board 110, and the mounting base 6 plays a role in supporting the plurality of magnetic cores. The mounting base 6 is provided with a plurality of through openings, and the two ends of the first winding 4 and the two ends of the second winding 5 are connected to the circuit board 110 through the corresponding through openings.

[0093] In the present application, no matter what structure the first magnetic core 1, the second magnetic core 2 and the third magnetic core 3 adopt, when the first winding 4 and the second winding 5 are respectively loaded with current, the different flow directions of the current or the winding directions of the windings will affect the paths of the magnetic flux in the multiple magnetic cores and bring different effects. The following text of the present application takes the first magnetic core 1 and the second magnetic core 2 as E-type magnetic cores and the third magnetic core 3 as I-type magnetic core as an example (EIE type inductor 120) to explain the flow direction of the magnetic flux and the corresponding effects.

[0094] Refer to the attached Figure 7 , Figure 7 The first winding 4 and the second winding 5 are shown as an example of a path of downward magnetic flux. Figure 7 In the example, the end of the first winding 4 close to the third magnetic core 3 is the current input end of the first winding 4 (arrow i1 indicates the direction of the current input to the first winding 4), and the end of the first winding 4 away from the third magnetic core 3 is the current output end of the first winding 4. The winding direction of the first winding 4 from one end close to the third magnetic core 3 to the other end of its two ends, that is, the winding direction of the first winding 4 from the current input end to the current output end, is from the outside to the inside in the figure.

[0095] Refer to the attached Figure 7 , the end of the second winding 5 close to the third magnetic core 3 is the current input end of the second winding 5 (arrow i2 indicates the direction of the current input to the first winding 4), and the end of the second winding 5 away from the third magnetic core 3 is the current output end of the second winding 5. The winding direction of the second winding 5 from one end close to the third magnetic core 3 to the other end of its two ends, that is, the winding direction of the second winding 5 from the current input end to the current output end, is from the inside to the outside on the drawing.

[0096] That is, in Figure 7 In the example, the winding directions of the first winding 4 and the second winding 5 are opposite. In this case, when the first winding 4 is loaded with current, the magnetic flux path of the first winding 4 on the first magnetic core 1 and the third magnetic core 3 is shown as the magnetic circuit L1. It can be understood that the magnetic flux generated by the first winding 4 will also flow to the second magnetic core 2 (this path is not drawn in the figure). When the second winding 5 is loaded with current, the magnetic flux path of the second winding 5 on the second magnetic core 2 and the third magnetic core 3 is shown as the magnetic circuit L2. It can be understood that the magnetic flux generated by the second winding 5 will also flow to the first magnetic core 1 (this path is not drawn in the figure).

[0097] It can be seen that under this type of magnetic flux path, the magnetic flux generated by the first winding 4 and the magnetic flux generated by the second winding 5 are superimposed on each other on the third magnetic core 3, and part of the magnetic flux generated by the first winding 4 and part of the magnetic flux generated by the second winding 5 cancel each other out on the first magnetic core 1 and the second magnetic core 2. Since the magnetic permeability of the third magnetic core 3 is low and the magnetic permeability of the first magnetic core 1 and the second magnetic core 2 is high (the magnetic resistance of the first magnetic core 1 and the second magnetic core 2 is small), the magnetic flux is more likely to flow through the first magnetic core 1 and the second magnetic core 2, so that more magnetic flux is canceled out on the first magnetic core 1 and the second magnetic core 2, increasing the coupling of the two windings, thereby reducing the peak-to-peak value (△I) of the inductor current.

[0098] in, Figure 8 The example shows the change of the peak-to-peak value of the two-phase inductor current of the inductor 120 with a phase difference of 180° using the above winding method. Figure 8 (a) may be the peak-to-peak value variation of the inductor current of the first winding 4, wherein ΔI1 is the original peak-to-peak value of the inductor current of the first winding 4, and ΔI2 is the reduced peak-to-peak value of the inductor current. Figure 8(b) may be the peak-to-peak value variation of the inductor current of the second winding 5, wherein ΔI3 is the original peak-to-peak value of the inductor current of the second winding 5, and ΔI4 is the reduced peak-to-peak value of the inductor current.

[0099] As the peak-to-peak value of the inductor current decreases, the change in magnetic flux density (△B) decreases, thereby reducing the power loss on the inductor 120 and also reducing the power loss on some devices in the circuit. For example, the power loss on the circuit switching devices (such as MOS tubes) is reduced, thereby improving the efficiency of the power converter 100.

[0100] In addition, since part of the magnetic flux is offset on the first magnetic core 1 and the second magnetic core 2, the magnetic flux of the first magnetic core 1 and the second magnetic core 2 is reduced, making the first magnetic core 1 and the second magnetic core 2 less likely to saturate. During design and production, the volume of the first magnetic core 1 and the second magnetic core 2 can be reduced, further reducing the volume and manufacturing cost of the inductor 120, thereby further reducing the volume and cost of the power converter 100.

[0101] Refer to the attached Fig. 9 , Fig. 9 Another path of the downward magnetic flux of the first winding 4 and the second winding 5 is shown as an example. Fig. 9 In the example, the end of the first winding 4 close to the third magnetic core 3 is the current input end of the first winding 4, and the end of the first winding 4 away from the third magnetic core 3 is the current output end of the first winding 4. The winding direction of the first winding 4 from one end close to the third magnetic core 3 to the other end of its two ends, that is, the winding direction of the first winding 4 from the current input end to the current output end, is from the outside to the inside in the figure.

[0102] Refer to the attached Fig. 9 , the end of the second winding 5 close to the third magnetic core 3 is the current input end of the second winding 5, and the end of the second winding 5 away from the third magnetic core 3 is the current output end of the second winding 5. The winding direction of the second winding 5 from one end close to the third magnetic core 3 to the other end of its two ends, that is, the winding direction of the second winding 5 from the current input end to the current output end, is also from the outside to the inside on the drawing.

[0103] That is, in Fig. 9 In the example, the winding direction of the first winding 4 and the second winding 5 is the same. In this case, when the first winding 4 is loaded with current, the magnetic flux path of the first winding 4 on the first magnetic core 1 and the third magnetic core 3 is shown as L3. It can be understood that the magnetic flux generated by the first winding 4 will also flow to the second magnetic core 2 (this path is not drawn in the figure). When the second winding 5 is loaded with current, the magnetic flux path of the second winding 5 on the second magnetic core 2 and the third magnetic core 3 is shown as L4. It can be understood that the magnetic flux generated by the second winding 5 will also flow to the first magnetic core 1 (this path is not drawn in the figure).

[0104] It can be seen that under this type of magnetic flux path, part of the magnetic flux generated by the first winding 4 and part of the magnetic flux generated by the second winding 5 cancel each other out on the third magnetic core 3, and the magnetic flux generated by the first winding 4 and the magnetic flux generated by the second winding 5 are superimposed on the first magnetic core 1 and the second magnetic core 2. Since the magnetic permeability of the third magnetic core 3 is relatively low, the third magnetic core 3 itself is not easy to saturate and can be made very small. When part of the magnetic flux on the third magnetic core 3 cancels each other out, the magnetic flux of the third magnetic core 3 is smaller, and the third magnetic core 3 is less likely to saturate, which can further reduce the volume of the third magnetic core 3, and thus further reduce the volume and manufacturing cost of the power converter 100.

[0105] The above examples are intended to explain the different effects brought about by different magnetic flux paths, and are not intended to limit the winding method and current direction of the present application.

[0106] In other examples, the end of the first winding 4 away from the third magnetic core 3 is the current input end of the first winding 4, and the end of the second winding 5 away from the third magnetic core 3 is the current input end of the second winding 5. Alternatively, the end of the first winding 4 close to the third magnetic core 3 is the current input end of the first winding 4, and the end of the second winding 5 away from the third magnetic core 3 is the current input end of the second winding 5. Alternatively, the end of the first winding 4 away from the third magnetic core 3 is the current input end of the first winding 4, and the end of the second winding 5 close to the third magnetic core 3 is the current input end of the second winding 5.

[0107] It is understandable that, regardless of the winding position and direction of the first winding 4 and the second winding 5, and regardless of the input position and output position of the current, when the current is loaded on the inductor 120, the path of the magnetic flux in the inductor 120 can be one of the following two situations: the first is that part of the magnetic flux generated by the first winding 4 and the second winding 5 is superimposed on the third magnetic core 3, and part of the magnetic flux is offset on the first magnetic core 1 and the second magnetic core 2; the second is that part of the magnetic flux generated by the first winding 4 and the second winding 5 is offset on the third magnetic core 3, and part of the magnetic flux is superimposed on the first magnetic core 1 and the second magnetic core 2. Different paths of magnetic flux will bring different effects to the inductor 120.

[0108] By using the inductor 120 of the present application, designers can adjust the winding directions of the first winding 4 and the second winding 5 as required, and can also adjust the flow direction of the current (i1 and i2) as required, so that the inductor 120 has the desired effect. In this way, the inductor 120 of the present application has higher flexibility in application.

[0109] In addition, the positions of the two ends of the winding (the current input end and the current output end) can be adjusted according to the setting requirements of the circuit board 110.

[0110] In the example where the first magnetic core 1 is an E-type magnetic core, the first winding 4 can be wound around the middle second magnetic column 12 among the three second magnetic columns 12 (the middle second magnetic column 12 can be called the middle column of the first magnetic core 1), and the two ends of the first winding 4 are located on different sides of the middle column of the first magnetic core 1. Fig. 9 In the example shown, the current input end of the first winding 4 is located on the left side of the center column of the first magnetic core 1 (the left side in the figure), and the current output end of the first winding 4 is located on the right side of the center column of the first magnetic core 1 (the right side in the figure).

[0111] In the example where the second magnetic core 2 is an E-type magnetic core, the second winding 5 can be wound on the fourth magnetic column 22 located in the middle among the three fourth magnetic columns 22 (the fourth magnetic column 22 in the middle can be called the middle column of the second magnetic core 2), and the two ends of the second winding 5 are located on different sides of the middle column of the second magnetic core 2. Fig. 9 In the example shown, the current input end of the second winding 5 is located on the left side of the middle column of the second magnetic core 2 , and the current output end of the second winding 5 is located on the right side of the middle column of the second magnetic core 2 .

[0112] Through the above design, the two ends of the winding are located on different sides of the center column of the wound magnetic core, which facilitates the connection of the first winding 4 and the second winding 5 with the circuit board 110 and is also beneficial to the layout and wiring of the product circuit board 110.

[0113] In other examples, the two ends of the first winding 4 may be located on the same side of the first magnetic core 1 . Similarly, the two ends of the second winding 5 may also be located on the same side of the second magnetic core 2 .

[0114] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An inductor, characterized in that: include: A first magnetic core, a second magnetic core and a third magnetic core, and a first winding and a second winding; The third magnetic core is located between the first magnetic core and the second magnetic core, and the magnetic permeability of the first magnetic core and the magnetic permeability of the second magnetic core are both greater than the magnetic permeability of the third magnetic core; the first winding is wound on the first magnetic core, and the second winding is wound on the second magnetic core.

2. The inductor according to claim 1, characterized in that: The first magnetic core includes a first magnetic column and a plurality of second magnetic columns, the first magnetic column extends along a first direction, the first magnetic column and the third magnetic core are arranged in a second direction, the first direction intersects with the second direction, the plurality of second magnetic columns are arranged between the first magnetic column and the third magnetic core at intervals along the first direction, and each of the second magnetic columns is connected to the first magnetic column.

3. The inductor according to claim 2, characterized in that: One end of each of the second magnetic columns facing away from the first magnetic column is in contact with the third magnetic core.

4. The inductor according to claim 2 or 3, characterized in that: The second magnetic core includes a third magnetic column and a plurality of fourth magnetic columns, the third magnetic column extends along the first direction, the third magnetic column and the third magnetic core are arranged in the second direction, the plurality of fourth magnetic columns are distributed between the third magnetic column and the third magnetic core at intervals along the first direction, and each of the fourth magnetic columns is connected to the third magnetic column.

5. The inductor according to claim 4, characterized in that: One end of each of the fourth magnetic columns facing away from the third magnetic column is in contact with the third magnetic core.

6. The inductor according to claim 4, characterized in that: The plurality of second magnetic columns include three second magnetic columns, the first winding is wound around one of the three second magnetic columns located in the middle, The plurality of fourth magnetic columns include three fourth magnetic columns, and the second winding is wound around a middle one of the three fourth magnetic columns.

7. A power converter, characterized in that: The inductor comprises the inductor according to any one of claims 1 to 6 and a plurality of bridge arms, wherein the first winding and the second winding are each connected to at least one of the bridge arms.

8. The power converter according to claim 7, characterized in that: One of the two ends of the first winding that is closer to the third magnetic core is the current input end of the first winding, and one of the two ends of the second winding that is closer to the third magnetic core is the current input end of the second winding; or The end of the first winding that is farther from the third magnetic core is the current input end of the first winding, and the end of the second winding that is farther from the third magnetic core is the current input end of the second winding.

9. The power converter according to claim 8, characterized in that: The winding direction of the first winding from one end closer to the third magnetic core to the other end is opposite to the winding direction of the second winding from one end closer to the third magnetic core to the other end.

10. The power converter according to claim 8, characterized in that: The winding direction of the first winding from one end closer to the third magnetic core to the other end is the same as the winding direction of the second winding from one end closer to the third magnetic core to the other end.

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