Inverter and integrated inductor

Abstract

The present application provides an inverter, comprising a DC-AC conversion circuit and a filter circuit, wherein the filter circuit is connected to the AC side of the DC-AC conversion circuit; the filter circuit comprises an integrated inductor, wherein the integrated inductor comprises a common-mode core, a differential-mode core, and at least two windings; the differential-mode core comprises a second core and a third core, wherein the common-mode core, the second core, and the third core are stacked in sequence; each winding is located between the third core and the second core, and is wound around the common-mode core and the second core, with at least two windings separated by the third core. The present application also provides an integrated inductor. The solution of the present application can ensure that common-mode interference and differential-mode interference are suppressed while reducing the product volume.

Description

Technical Field

[0001] The present application relates to the photovoltaic field, and in particular to an inverter and an integrated inductor. Background Art

[0002] With the advancement of modern industrial technology, various nonlinear and time-varying power electronic devices, such as inverters, are increasingly being used in power systems. While this improves industrial production efficiency, it also has many negative side effects. Interference electromagnetic fields in inverters can generate differential-mode currents between conductors or common-mode currents between conductors and the ground. Both of these can interfere with loads in the power system, affecting their proper operation. Therefore, filter inductors are typically installed in power systems. These filter inductors include differential-mode inductors and common-mode inductors. The differential-mode inductor is used to suppress differential-mode interference, while the common-mode inductor is used to suppress common-mode interference. However, the common-mode and differential-mode inductors are manufactured and installed separately as separate components. This results in a larger board area, lower power density, and higher costs associated with separate manufacturing. Summary of the Invention

[0003] The present application provides an inverter, an integrated inductor, and a circuit board assembly that can reduce the board area occupied by the filter inductor, improve power density, and reduce costs.

[0004] In a first aspect, the present application provides an inverter, comprising a DC-AC conversion circuit and a filter circuit, wherein the filter circuit is connected to the AC side of the DC-AC conversion circuit; the filter circuit comprises an integrated inductor, the integrated inductor comprises a common-mode magnetic core, a differential-mode magnetic core and at least two windings; the differential-mode magnetic core comprises a second magnetic core and a third magnetic core, and the common-mode magnetic core, the second magnetic core and the third magnetic core are stacked in sequence; each winding is located between the third magnetic core and the second magnetic core, and is wound around the common-mode magnetic core and the second magnetic core, and at least two windings are separated by the third magnetic core.

[0005] In this solution, the filter circuit is used to perform filtering, suppress differential-mode resonance, suppress common-mode interference, and other processes. The integrated inductor is arranged on a circuit board. The stacked arrangement can refer to the common-mode core, the second core, and the third core being arranged in sequence in a direction perpendicular to the circuit board. There is a gap between the third core and the second core, and the winding is located in the gap. The third core can have multiple partition structures, and two adjacent windings are separated by a partition structure. The winding and the common-mode core form a common-mode inductor, and the winding and the second and third cores form a differential-mode inductor.

[0006] This solution integrates the common-mode and differential-mode inductors into a single component by sharing windings with the common-mode and differential-mode cores. This saves space and reduces costs, while also minimizing copper losses, which in turn reduce their impact on inverter system efficiency, effectively improving the efficiency of the integrated inductor. When the integrated inductor is assembled onto a circuit board, the stacked common-mode and differential-mode cores save board space and increase power density.

[0007] In an implementation of the first aspect, the third magnetic core and the second magnetic core enclose at least two mounting holes, and each winding passes through a corresponding mounting hole. In this solution, the third magnetic core and the second magnetic core can be enclosed to form at least two mounting holes.

[0008] The differential-mode core structure of this type is reliable and has good mass production performance, and is conducive to realizing the stacking arrangement of the differential-mode core and the common-mode core.

[0009] In one implementation of the first aspect, the third magnetic core includes at least two magnetic columns and an upper magnetic core, at least two magnetic columns are located between the upper magnetic core and the second magnetic core, and the upper magnetic core, at least two magnetic columns and the second magnetic core surround at least two mounting holes. In this solution, the magnetic columns and the upper magnetic core can be directly connected or have an air gap, and the magnetic columns and the second magnetic core are directly connected or have an air gap. The winding is located between the upper magnetic core and the second magnetic core, and adjacent windings are separated by a magnetic column. In this solution, a portion of the second magnetic core, any two adjacent magnetic columns and a portion of the upper magnetic core surround to form a mounting hole, and constitute a differential mode magnetic circuit. The differential mode core structure of this structure is simple, reliable, and has good mass production, which is conducive to the stacking arrangement of differential mode cores and common mode cores.

[0010] In one implementation of the first aspect, the third magnetic core includes at least two magnetic columns, one end of each magnetic column is close to the second magnetic core, at least two magnetic columns converge at one end away from the second magnetic core, and at least two magnetic columns and the second magnetic core form at least two mounting holes. In this solution, convergence can refer to the connection of the ends of the magnetic columns away from the second magnetic core, or it can refer to the ends of the magnetic columns away from the second magnetic core approaching each other and forming an air gap. In this solution, a portion of the second magnetic core and any two adjacent magnetic columns are surrounded to form a mounting hole and constitute a differential mode magnetic circuit. The differential mode magnetic circuit provided by this solution has a simple structure, which is conducive to miniaturization of the integrated inductor.

[0011] In one implementation of the first aspect, a common-mode magnetic core has a first through-hole; a second magnetic core is located axially on one side of the common-mode magnetic core, the second magnetic core having a second through-hole that communicates with the first through-hole; each mounting hole communicates with the second through-hole; and each winding passes through a mounting hole, a second through-hole, and a first through-hole. In this embodiment, both the common-mode magnetic core and the second magnetic core can be annular. This embodiment defines a specific stacked structure of the common-mode magnetic core and the differential-mode magnetic core. This stacked structure is simple, reliable, and highly manufacturable, facilitating miniaturization of the integrated inductor.

[0012] In one implementation of the first aspect, the axial projection of the second magnetic core falls within the range of the common-mode magnetic core. In this solution, the projection of the second magnetic core in the stacking direction is located within the outline boundary of the common-mode magnetic core, which can save the projected area of ​​the integrated inductor in the stacking direction and save board area.

[0013] In one implementation of the first aspect, the axial projection of the third magnetic core falls within the circumscribed circle of the axial projections of at least two windings. In this solution, the axial projections of all windings can be located within the same circle, and the axial projection of each winding is connected to this circle, which can be referred to as a circumscribed circle. In this solution, the circumscribed circle determines the maximum outline size of the integrated inductor. By ensuring that the axial projection of the third magnetic core does not exceed the circumscribed circle, the axially projected area of ​​the integrated inductor can be reduced, thereby saving board space.

[0014] In one implementation of the first aspect, the integrated inductor includes a non-magnetic plate disposed between the common-mode magnetic core and the second magnetic core, the non-magnetic plate forming a first air gap; or, the integrated inductor includes a plurality of non-magnetic pillars disposed between the common-mode magnetic core and the second magnetic core, the plurality of non-magnetic pillars forming the first air gap; or, the surface of the common-mode magnetic core and / or the surface of the second magnetic core is covered with an insulating layer, the insulating layer forming the first air gap. This solution isolates the magnetic circuits of the common-mode magnetic core and the differential-mode magnetic core via the first air gap between the common-mode magnetic core and the differential-mode magnetic core, making the common-mode magnetic circuit and the differential-mode magnetic circuit independent of each other and thus improving the overall anti-saturation capability of the integrated inductor.

[0015] In an implementation of the first aspect, the first air gap is greater than or equal to 0.5 mm. When the first air gap is within this value range, the integrated inductor can be compactly arranged, reducing the installation space occupied, while optimizing the overall anti-saturation capability of the integrated inductor.

[0016] In the second aspect, the present application provides an integrated inductor, comprising a common-mode magnetic core, a differential-mode magnetic core and at least two windings; the differential-mode magnetic core comprises a second magnetic core and a third magnetic core, and the common-mode magnetic core, the second magnetic core and the third magnetic core are stacked in sequence; each winding is located between the third magnetic core and the second magnetic core, and is wound around the common-mode magnetic core and the second magnetic core, and at least two windings are separated by the third magnetic core.

[0017] In this solution, the integrated inductor is arranged on a circuit board. The stacked arrangement may refer to the common-mode core, the second core, and the third core being arranged in sequence perpendicular to the circuit board. A gap exists between the third core and the second core, and the winding is located within this gap. The third core may have multiple partitioning structures, with each partitioning structure separating two adjacent windings. The winding and the common-mode core form a common-mode inductor, and the winding and the second and third cores form a differential-mode inductor.

[0018] This solution integrates the common-mode and differential-mode inductors into a single component by sharing windings with the common-mode and differential-mode cores. This saves space and reduces costs, while also minimizing copper losses, which in turn reduce their impact on inverter system efficiency, effectively improving the efficiency of the integrated inductor. When the integrated inductor is assembled onto a circuit board, the stacked common-mode and differential-mode cores save board space and increase power density.

[0019] In an implementation of the second aspect, the third magnetic core and the second magnetic core enclose at least two mounting holes, and each winding passes through a corresponding mounting hole. In this solution, the third magnetic core and the second magnetic core can be enclosed to form at least two mounting holes.

[0020] The differential-mode core structure of this type is reliable and has good mass production performance, and is conducive to realizing the stacking arrangement of the differential-mode core and the common-mode core.

[0021] In one implementation of the second aspect, the third magnetic core includes at least two magnetic columns and an upper magnetic core, at least two magnetic columns are located between the upper magnetic core and the second magnetic core, and the upper magnetic core, at least two magnetic columns and the second magnetic core surround at least two mounting holes. In this solution, the magnetic columns and the upper magnetic core can be directly connected or have an air gap, and the magnetic columns and the second magnetic core are directly connected or have an air gap. The winding is located between the upper magnetic core and the second magnetic core, and adjacent windings are separated by a magnetic column. In this solution, a portion of the second magnetic core, any two adjacent magnetic columns and a portion of the upper magnetic core surround to form a mounting hole, and constitute a differential mode magnetic circuit. The differential mode magnetic core structure of this structure is simple, reliable, and has good mass production, which is conducive to the stacking arrangement of differential mode magnetic cores and common mode magnetic cores.

[0022] In one implementation of the second aspect, the third magnetic core includes at least two magnetic columns, one end of each magnetic column is close to the second magnetic core, at least two magnetic columns converge at one end away from the second magnetic core, and at least two magnetic columns and the second magnetic core form at least two mounting holes. In this solution, convergence can refer to the connection of the ends of the magnetic columns away from the second magnetic core, or it can refer to the ends of the magnetic columns away from the second magnetic core approaching each other and forming an air gap. In this solution, a portion of the second magnetic core and any two adjacent magnetic columns are surrounded to form a mounting hole and constitute a differential mode magnetic circuit. The differential mode magnetic circuit provided by this solution has a simple structure, which is conducive to miniaturization of the integrated inductor.

[0023] In one implementation of the second aspect, the common-mode core has a first through-hole; a second magnetic core is located axially on one side of the common-mode core, the second magnetic core having a second through-hole that communicates with the first through-hole; each mounting hole communicates with the second through-hole; and each winding passes through a mounting hole, a second through-hole, and a first through-hole. In this embodiment, both the common-mode core and the second magnetic core can be annular. This embodiment defines a specific stacked structure of the common-mode core and the differential-mode core. This stacked structure is simple, reliable, and highly manufacturable, facilitating miniaturization of the integrated inductor.

[0024] In one implementation of the second aspect, the axial projection of the second magnetic core falls within the range of the common-mode magnetic core. In this solution, the projection of the second magnetic core in the stacking direction is located within the outline boundary of the common-mode magnetic core, which can save the projected area of ​​the integrated inductor in the stacking direction and save board area.

[0025] In one implementation of the second aspect, the axial projection of the third magnetic core falls within the circumscribed circle of the axial projections of at least two windings. In this solution, the axial projections of all windings can be located within the same circle, and the axial projection of each winding is connected to this circle, which can be referred to as a circumscribed circle. In this solution, the circumscribed circle determines the maximum outline size of the integrated inductor. By ensuring that the axial projection of the third magnetic core does not exceed the circumscribed circle, the axially projected area of ​​the integrated inductor can be reduced, thereby saving board space.

[0026] In one implementation of the second aspect, the third magnetic core has a rotationally symmetrical structure. In this solution, by limiting the third magnetic core to a rotationally symmetrical structure, the internal components of the third magnetic core can be evenly distributed, the structure is more rational, and it is easier to arrange it in conjunction with the windings. This makes the integrated inductor layout compact, reduces the installation space occupied, and ensures the operating performance of the differential mode magnetic circuit.

[0027] In one implementation of the second aspect, the integrated inductor includes a non-magnetic plate disposed between the common-mode magnetic core and the second magnetic core, the non-magnetic plate forming a first air gap; or, the integrated inductor includes a plurality of non-magnetic pillars disposed between the common-mode magnetic core and the second magnetic core, the plurality of non-magnetic pillars forming the first air gap; or, the surface of the common-mode magnetic core and / or the surface of the second magnetic core is covered with an insulating layer, the insulating layer forming the first air gap. This solution isolates the magnetic circuits of the common-mode magnetic core and the differential-mode magnetic core via the first air gap between the common-mode magnetic core and the differential-mode magnetic core, making the common-mode magnetic circuit and the differential-mode magnetic circuit independent of each other and independent of each other, thereby improving the overall anti-saturation capability of the integrated inductor.

[0028] In an implementation of the second aspect, the first air gap is greater than or equal to 0.5 mm. When the first air gap is within this value range, the integrated inductor can be compactly arranged, reducing the occupied installation space, while optimizing the overall anti-saturation capability of the integrated inductor.

[0029] In one implementation of the second aspect, a second air gap is provided between the second magnetic core and the third magnetic core. In this solution, the second magnetic core and the third magnetic core are both part of a differential mode magnetic core, and a second air gap is provided between the second magnetic core and the third magnetic core, i.e., an air gap exists within the differential mode magnetic core. The second air gap can improve the magnetic performance of the differential mode magnetic core.

[0030] In one implementation of the second aspect, a third air gap is provided between each magnetic column and the upper magnetic core. In this solution, the magnetic columns and the upper magnetic core are both part of the differential mode magnetic core, and the third air gap is provided between the magnetic columns and the upper magnetic core, that is, an air gap exists within the differential mode magnetic core. The third air gap can improve the magnetic performance of the differential mode magnetic core.

[0031] In a third aspect, the present application provides a circuit board assembly comprising a circuit board and the aforementioned integrated inductor, wherein the windings of the integrated inductor are connected to the circuit board. In this solution, when the windings of the integrated inductor are mounted on the circuit board, they occupy a smaller area in a first direction, thereby saving installation space for other components on the circuit board and making the component layout of the circuit board more reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the circuit framework structure of a traditional inverter;

[0033] Figure 2 1 is a schematic diagram of the circuit framework structure of the inverter according to an embodiment of the present application;

[0034] Figure 3 1 is a schematic diagram of the assembly structure of the inverter according to an embodiment of the present application;

[0035] Figure 4 1 is a schematic diagram of the assembly structure of the integrated inductor according to an embodiment of the present application;

[0036] Figure 5 is a schematic diagram of the decomposed structure of the integrated inductor according to an embodiment of the present application;

[0037] Figure 6 is a schematic top view of the integrated inductor according to an embodiment of the present application;

[0038] Figure 7 1 is a schematic structural diagram of a differential-mode magnetic core of an integrated inductor according to an embodiment of the present application;

[0039] Figure 8 is a schematic structural diagram of the third magnetic core of the integrated inductor according to an embodiment of the present application;

[0040] Figure 9 is a schematic structural diagram of the winding of the integrated inductor according to an embodiment of the present application;

[0041] Figure 10 It is a schematic structural diagram of a circuit board according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] Explanation of some terms

[0043] Parallel: The parallelism defined in the embodiments of the present application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, which allows for situations where the absolute parallelism is not caused by factors such as assembly tolerance, design tolerance, and the influence of structural flatness.

[0044] Vertical: The vertical defined in the embodiments of the present application is not limited to an absolute vertical intersection relationship (an angle of 90 degrees). It allows for non-absolute vertical intersection relationships caused by factors such as assembly tolerance, design tolerance, and the influence of structural flatness. It allows for errors in a small angle range. For example, the assembly error range of 80 to 100 degrees can be understood as a vertical relationship.

[0045] The terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features.

[0046] The present application is described below by way of examples.

[0047] Inverters are widely used in power supply or power control scenarios such as photovoltaics and frequency converters. The differential-mode and common-mode interference present in these scenarios can adversely affect circuit systems and are typically filtered using filtering circuits. Common-mode signals are signals with equal amplitude and phase. Differential-mode signals are signals with equal amplitude and opposite phase. In a closed circuit, common-mode interference signals have equal amplitude and direction on both conductors. They are essentially interference caused by the voltage difference between the two conductors and the ground in the closed loop. Differential-mode interference signals have equal amplitude and opposite phase between the two conductors. They are essentially interference between the two conductors.

[0048] Figure 1 The following figure shows a circuit framework structure of a traditional inverter. Figure 1 As shown, the inverter may include a DC-AC converter circuit (DC-AC) and a filter circuit. The filter circuit is connected to the AC side of the DC-AC converter circuit, and the DC-AC converter circuit (DC-AC) can be connected to the power grid (AC GRID) through the filter circuit. Schematically, the filter circuit may include an inductor L1, a filter capacitor C, a differential mode inductor L2, and a common mode inductor L_cm. Schematically, the inductor L1 and the filter capacitor C can filter the square wave output by the DC-AC into a sine wave. The differential mode inductor L2 can be used for filtering and suppressing differential mode resonance, and the common mode inductor L_cm can be used to suppress common mode interference.

[0049] In the above solution, the common-mode inductor L_cm and differential-mode inductor L2 in the inverter are independent and installed as two separate inductor components. However, this solution has the following drawbacks: the two inductors occupy a large area when installed on the circuit board, resulting in a low power density, and the cost of manufacturing the two inductors separately is high.

[0050] In view of this, if Figure 2 As shown, the solution of the embodiment of the present application provides an inverter. Consistent with the above-mentioned traditional solution, the inverter of the embodiment of the present application may include a DC-AC conversion circuit and a filter circuit. The filter circuit is connected to the AC side of the DC-AC conversion circuit, and the DC-AC conversion circuit can be connected to the power grid through the filter circuit. Schematically, the filter circuit may include an inductor L1 and a filter capacitor C. Different from the above-mentioned traditional solution, the filter circuit of the embodiment of the present application includes an integrated inductor L0, which integrates the common-mode inductor and the differential-mode inductor into one component, wherein the common-mode inductor and the differential-mode inductor are stacked, which can reduce the volume and board area, reduce costs, and improve power density. This will be described in detail below.

[0051] like Figure 3As shown, an embodiment of the present application provides an inverter 300, which may include a circuit board assembly 100 and a housing 200. The housing 200 surrounds the outside of the circuit board assembly 100 and serves to accommodate and protect the circuit board assembly 100. The circuit board assembly 100 may include electronic components such as an integrated inductor 10, a circuit board 20, and a control chip 30. The integrated inductor 10 and the control chip 30 may both be arranged on the circuit board 20. The positions of the integrated inductor 10 and the control chip 30 on the circuit board 20 may be set as needed, and are not limited in the embodiment of the present application.

[0052] like Figure 4 、 Figure 5 and Figure 6 As shown, the integrated inductor 10 may include a first magnetic core 1 , an air gap plate 2 , a differential mode magnetic core 4 and a winding 3 .

[0053] like Figure 4 and Figure 5 As shown, the first magnetic core 1 can be a circular ring structure. The first magnetic core 1 has a first through hole 1a, and the first through hole 1a passes through the first magnetic core 1 along the axis direction of the first magnetic core 1. The axis direction of the first through hole 1a is the first direction, see Figure 5 , the direction in which arrow D extends is the first direction. In the embodiment of the present application, the first magnetic core 1 is a circular ring structure. In other embodiments, the first magnetic core 1 is not limited to a circular ring structure, but may also be other polygonal ring structures. In the embodiment of the present application, the first magnetic core 1 can be made of magnetic materials such as ferrite and amorphous ribbon.

[0054] like Figure 4 and Figure 5 As shown, the air gap plate 2 is an annular plate structure with a through hole. The air gap plate 2 is located on one side of the first magnetic core 1 in a first direction. The air gap plate 2 is bonded to the first magnetic core 1, and the first through hole 1a is connected to the through hole of the air gap plate 2. The air gap plate 2 can be made of a non-magnetic plate material such as an epoxy plate or a polyvinyl chloride (PVC) plate.

[0055] Next, the structure of the differential mode magnetic core 4 and the positional relationship among the differential mode magnetic core 4 , the first magnetic core 1 and the air gap plate 2 will be described.

[0056] like Figure 5 and Figure 7 As shown, the differential mode magnetic core 4 may include a second magnetic core 41 and a third magnetic core.

[0057] like Figure 5 and Figure 7As shown, the second magnetic core 41 can be a circular ring structure. The second magnetic core 41 has a second through hole 41a, and the second through hole 41a passes through the second magnetic core 41 along the axial direction of the second magnetic core 41. One side of the second magnetic core 41 is the first surface 41b of the second magnetic core 41. The second magnetic core can be made of magnetic materials such as silicon steel magnetic material and amorphous strip. In the embodiment of the present application, the second magnetic core 41 is a circular ring structure. In other embodiments, the second magnetic core 41 is not limited to a circular ring structure, but can also be other polygonal ring structures.

[0058] like Figure 4 and Figure 5 As shown, the second magnetic core 41 is located on the side of the air gap plate 2 away from the first magnetic core 1 in the first direction, so that the air gap plate 2 is located between the first magnetic core 1 and the second magnetic core 41, and the first surface 41b of the second magnetic core 41 is away from the air gap plate 2, and the first direction is approximately perpendicular to the first surface 41b.

[0059] In the first direction, the distance between the first magnetic core 1 and the second magnetic core 41 is a first air gap. In the embodiment of the present application, the first air gap can be formed by the air gap plate 2 between the second magnetic core 41 and the first magnetic core 1.

[0060] In other embodiments, an insulating layer may be provided on the surface of the second magnetic core 41 and / or the surface of the first magnetic core 1 (schematically, the insulating layer may be a shell wrapping the outer surface of the second magnetic core 41 and / or the first magnetic core 1) to form a first air gap.

[0061] Alternatively, a first air gap may be formed by forming a gap (with air in the gap) between the first magnetic core 1 and the second magnetic core 41. Several support columns with low magnetic permeability may be provided in the gap to support the first magnetic core 1 and the second magnetic core 41.

[0062] Alternatively, other low-permeability materials may be filled between the first magnetic core 1 and the second magnetic core 41 to form a first air gap, and the low-permeability material fills the space between the first magnetic core 1 and the second magnetic core 41 .

[0063] In an embodiment of the present application, the size of the outer circumference of the second magnetic core 41 can be basically the same as the size of the outer circumference of the first magnetic core 1; in other embodiments, the shape and size of the second magnetic core 41 can be designed as needed, and it is only necessary to ensure that the projection of the second magnetic core in the first direction falls within the projection of the first magnetic core 1.

[0064] The third magnetic core can be a rotationally symmetrical structure, and its rotational symmetry center can be the axial direction of the second magnetic core 41. The projection of the third magnetic core along the first direction will fall within the circumscribed circle of the projection of the winding 3 in the first direction, for example, it can all fall within the first surface 41b. The third magnetic core and the second magnetic core 41 enclose at least two mounting holes, wherein enclosing the mounting holes means that the second magnetic core 41 and the third magnetic core are directly connected to enclose the mounting holes, or it can mean that there is a small gap between the second magnetic core 41 and the third magnetic core, but it can still be regarded as enclosing the mounting holes on a macro scale. The axes of each mounting hole intersect along the first direction, for example, the axes of the mounting holes are perpendicular to the first direction.

[0065] In one embodiment, the third magnetic core may include a magnetic column 42 and an upper magnetic core 43 .

[0066] like Figure 5 and Figure 8 As shown, the magnetic column 42 can be a columnar structure. The magnetic column 42 has a second surface 42a and a third surface 42b opposite to each other. The second surface 42a and / or the third surface 42b can be flat or curved. The magnetic column 42 can be made of magnetic materials such as silicon steel magnetic material, amorphous strip, etc. The number of magnetic columns 42 can be multiple. In the embodiment of the present application, the number of magnetic columns 42 can be three to generate a three-phase differential mode inductor; in other application embodiments, the number of magnetic columns 42 can be designed as needed.

[0067] like Figure 4 、 Figure 5 and Figure 8As shown, three magnetic pillars 42 are located on the side of the second magnetic core 41 having the first surface 41b in the first direction, and the three magnetic pillars 42 are evenly spaced around the second through hole 41a. The second surfaces 42a of the magnetic pillars 42 are all facing the inner side of the second magnetic core 41, and the third surfaces 42b of the magnetic pillars 42 are all facing the outer peripheral side of the second magnetic core 41. At least a portion of the projection of the magnetic pillars 42 in the first direction falls within the first surface 41b. For example, the projection of the magnetic pillars 42 in the first direction can fall entirely within the first surface 41b. When the second surface 42a and the third surface 42b are planes, the second surface 42a and the third surface 42b are both perpendicular to the first surface 41b. When the second surface 42a and the third surface 42b are curved surfaces, the generatrix of the second surface 42a and the third surface 42b is approximately perpendicular to the first surface 41b. The generatrix of the second surface 42a and the third surface 42b can be the moving line of the curved surface formed by either the second surface 42a or the third surface 42b. A second air gap may be provided between each magnetic column 42 and the second magnetic core 41. The second air gap may have a value ranging from 0.1 mm to 1 mm. Illustratively, the second air gap may be formed using an air gap plate or adhesive. Providing the second air gap enables the differential-mode magnetic core 4 and the integrated inductor 10 to have corresponding magnetic properties. In other embodiments, the second air gap may not be present.

[0068] like Figure 4 、 Figure 5 and Figure 6 As shown, the upper magnetic core 43 can be a circular ring structure. The upper magnetic core 43 can be made of magnetic materials such as silicon steel magnetic material, amorphous strip material, iron powder core magnetic material, etc. The upper magnetic core 43 is located on the side of the magnetic column 42 away from the second magnetic core 41, and the upper magnetic core 43 is approximately parallel to the second magnetic core 41. There is a third air gap between the upper magnetic core 43 and each magnetic column 42, and the value range of the third air gap can be 0.1mm-1mm. Schematically, the third air gap can be formed by using an air gap plate or adhesive. Setting the third air gap can make the differential mode magnetic core 4 and the integrated inductor 10 have better magnetic properties. In other embodiments, there may be no third air gap.

[0069] like Figure 4 As shown, the projection of the upper magnetic core 43 in the first direction falls within the circumscribed circle of the projections of the three windings 3 in the first direction (the assembly and cooperation of the three windings 3 with the first magnetic core 1, the second magnetic core 41 and the magnetic column 42 will be further described below).

[0070] In an embodiment of the present application, the upper magnetic core 43 can be a circular ring structure with a shape and size approximately the same as the second magnetic core 41. In other embodiments, unlike the above embodiments, the upper magnetic core is not limited to a circular ring structure, but can also be other closed structures (including but not limited to a closed square ring structure), or the upper magnetic core can include several spaced-apart sub-cores, each sub-core corresponding to two magnetic columns.

[0071] like Figure 4 As shown, the first magnetic core 1, the second magnetic core 41, the magnetic column 42 and the upper magnetic core 43 are stacked in sequence along the first direction. The first magnetic core 1 can be a common mode magnetic core, and the second magnetic core 41, the three magnetic columns 42 and the upper magnetic core 43 together form a differential mode magnetic core 4. In the differential mode magnetic core 4, as shown in FIG. Figure 7 As shown, a portion of the second magnetic core 41, any two adjacent magnetic pillars 42, and a portion of the upper magnetic core 43 surround and form a mounting hole 4a. The axial direction of the mounting hole 4a intersects the first direction, for example, the axial direction of the mounting hole 4a is perpendicular to the first direction. In the embodiment of the present application, since there are three magnetic pillars 42, three mounting holes 4a are formed.

[0072] In another embodiment, the third magnetic core may include a magnetic column, the shape and material of which may be approximately the same as the magnetic column 42 in the above embodiment, and the number of magnetic columns may be multiple. The multiple magnetic columns are all located on the side of the second magnetic core 41 away from the first magnetic core 1 in the first direction and are evenly distributed around the second through hole 41a. One end of each magnetic column is close to the second magnetic core, and the other ends of the multiple magnetic columns converge (convergence can mean that one end of the multiple magnetic columns is connected to each other, or that one end of the multiple magnetic columns is close to each other and has a certain air gap). A second air gap is formed between each magnetic column and the second magnetic core. The value range and composition of the second air gap can be approximately the same as the second air gap in the above embodiment, and will not be described in detail here. In this embodiment, the first magnetic core 1, the second magnetic core 41 and the multiple magnetic columns are stacked in sequence along the first direction. The first magnetic core 1 can be a common-mode magnetic core, and the second magnetic core 41 and the multiple magnetic columns together constitute a differential-mode magnetic core. In the differential-mode magnetic core, a portion of the second magnetic core 41 and any two adjacent magnetic columns are surrounded to form a mounting hole. The axial direction of the mounting hole intersects with the first direction. For example, the axial direction of the mounting hole may be perpendicular to the first direction.

[0073] The above mainly describes the positional relationship between the common-mode core, the differential-mode core 4 and the air gap plate 2 in the integrated inductor 10. Next, the structure of the winding 3 and the assembly and coordination of the winding 3, the differential-mode core 4 and the first magnetic core 1 will be described in detail.

[0074] In the embodiment of the present application, the winding 3 is formed by winding a wire covered with an insulating layer. The winding 3 may be, for example, an enameled wire or a film-coated wire. Figure 9As shown, the winding 3 includes a coil body 31 and a wiring pin 32, which are connected to each other, and the coil body 31 has a through hole surrounded by a coil. In one embodiment, there can be two wiring pins 32, which are respectively located on both sides of the coil body 31 and are approximately tangent to the coil body 31. In other embodiments, the wiring pins 32 can be located on the same side of the coil body 31. The different distribution methods of the wiring pins 32 on the coil body 31 will also affect the different installation areas occupied by the integrated inductor 10 on the circuit board 20, so the location of the wiring pins 32 can be designed as needed. The number of windings 3 is set corresponding to the number of magnetic columns 42, and there are at least two windings 3, for example, there can be three. The number of coil turns of each winding 3 is the same, and the winding direction of each winding 3 is also the same.

[0075] like Figure 4 、 Figure 5 and Figure 9 As shown, the coil body 31 of each winding 3 passes through the first through-hole 1a, the through-hole of the air gap plate 2, the second through-hole 41a, and a mounting hole 4a, so that each winding 3 is wound around the first magnetic core 1, the air gap plate 2, and the differential mode magnetic core. The through-hole of each coil body 31 accommodates a portion of the first magnetic core 1, a portion of the air gap plate 2, and a portion of the second magnetic core 41. The connection pins 32 of the winding 3 are all located on the side of the first magnetic core 1 away from the second magnetic core 41 in the first direction. Figure 4 As shown, the three windings 3 can be evenly distributed on the first magnetic core 1 , with gaps between adjacent windings and a spacing between every two windings 3 .

[0076] like Figure 4 As shown, since the first magnetic core 1 is a closed annular magnetic core, the first magnetic core 1 constitutes a closed common mode magnetic circuit A ( Figure 2 (The figure only shows a portion of the common-mode magnetic circuit A, not the entire common-mode magnetic circuit A). The first magnetic core 1 and each winding 3 form a common-mode inductor, which is used to suppress common-mode interference. By way of example and not limitation, the common-mode inductance formed between any winding 3 and the first magnetic core 1 can be adjusted by adjusting the number of turns of the winding 3 or the cross-sectional area of ​​the first magnetic core 1.

[0077] like Figure 4 As shown, the differential mode core 4 constitutes three differential mode magnetic circuits B (as shown in FIG. Figure 4 As shown, Figure 4(Only two differential-mode magnetic circuits B are shown, not all differential-mode magnetic circuits B are identified.) A portion of the second magnetic core 41, any two adjacent magnetic columns 42, and a portion of the upper magnetic core 43 each form a differential-mode magnetic circuit B, with each magnetic column 42 serving as a common core for two adjacent differential-mode magnetic circuits B. The differential-mode magnetic core 4 and the winding 3 surrounding it form a differential-mode inductor for suppressing differential-mode current. Using the magnetic columns 42 as a common core reduces the volume of the differential-mode magnetic core 4, facilitates assembly, provides greater flexibility, and improves assembly efficiency.

[0078] The first air gap between the differential mode magnetic core 4 and the first magnetic core 1 can isolate the differential mode magnetic core 4 from the first magnetic core 1 , ensuring that the differential mode magnetic circuit B and the common mode magnetic circuit A are independent of each other and do not interfere with each other.

[0079] In this embodiment, the second air gap and the third air gap inside the differential mode magnetic core 4 can improve the stability of the magnetic field of the integrated inductor 10, so that the integrated inductor 10 has better magnetic properties. In other embodiments, the second air gap and / or the third air gap may not be provided.

[0080] In the above-mentioned embodiment, the first magnetic core 1 and the second magnetic core 41 are both closed ring structures. This is just an example. In fact, the core structures of the first magnetic core 1 and the second magnetic core 41 can be set to any shape as needed and are not limited to closed ring structures.

[0081] In the above embodiment, the number of windings 3 and magnetic columns 42 is three, forming a three-phase integrated inductor. In other embodiments, four windings 3 and four magnetic columns 42 can be provided to form a three-phase four-wire integrated inductor. Alternatively, two windings 3 and two magnetic columns 42 can be provided to form a two-phase integrated inductor, which can be used, for example, in a single-phase energy storage inverter.

[0082] Combine Figure 3 and Figure 10 As shown, the circuit board 20 is provided with an inductor mounting area 201, and a soldering pad 202 is provided within the inductor mounting area 201. The inductor mounting area 201 is used to position and mount the integrated inductor 10. The outline of the inductor mounting area 201 is substantially consistent with the projection of the outer outline of the integrated inductor 10 in a first direction. Therefore, the area of ​​the inductor mounting area 201 is the area occupied by the integrated inductor 10 on the circuit board 20. The soldering pad 202 is used to correspond to the connection pins 32 of the winding 3, so that the connection pins 32 are soldered to the soldering pad 202. The position distribution of the soldering pad 202 within the inductor mounting area 201 depends on the position distribution of the connection pins 32. The distribution position of the soldering pad 202 can be designed as needed, and no further settings are given here.

[0083] Traditional common-mode inductors and differential-mode inductors are usually manufactured and installed as two separate devices, occupying a large area on the circuit board and having a low power density.

[0084] The integrated inductor 10 of the embodiment of the present application integrates the differential-mode inductor and the common-mode inductor, greatly reducing the volume of the integrated inductor 10 and the board area occupied on the circuit board 20, thereby improving the power density and reducing the cost. In addition, the differential-mode magnetic core 4 and the first magnetic core 1 share the three-phase winding 3. Under the premise of ensuring the suppression of differential-mode current and common-mode current, the use of the winding 3 can be reduced, effectively reducing copper loss, thereby reducing the impact of copper loss on the efficiency of the inverter system, and effectively improving the efficiency of the integrated inductor 10. At the same time, there is a first air gap between the differential-mode magnetic core 4 and the first magnetic core 1 of the embodiment of the present application, which can make the differential-mode magnetic circuit B and the common-mode magnetic circuit A independent of each other and prevent coupling. In the case of large current, the magnetic flux of the differential-mode magnetic core 4 will not occupy the magnetic flux of the first magnetic core and cause it to be oversaturated. Therefore, the integrated inductor 10 provided by the embodiment of the present application can withstand larger currents and has excellent anti-magnetic saturation capability.

[0085] Furthermore, the integrated inductor 10 of the present embodiment has a stacked layout. The projections of the individual magnetic cores of the differential-mode magnetic cores 4 along the first direction overlap significantly with the projections of the first magnetic core 1 along the first direction. Furthermore, the magnetic pillars 42 of the differential-mode magnetic cores 4 serve as a common core shared by adjacent differential-mode magnetic circuits. These features reduce the board area occupied by the magnetic pillars 42 along the first direction. Therefore, when the integrated inductor 10 is mounted on the circuit board 20, the area of ​​the inductor mounting area 201 can be significantly reduced, freeing up mounting space for other components on the circuit board 20 and further reducing the volume of the circuit board assembly 100.

[0086] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An inverter, characterized in that: It includes a DC-AC conversion circuit and a filter circuit, wherein the filter circuit is connected to the AC of the DC-AC conversion circuit. The filter circuit includes an integrated inductor, which includes a common-mode magnetic core, a differential-mode magnetic core, and at least two windings; the differential-mode magnetic core includes a second magnetic core and a third magnetic core, and the common-mode magnetic core, the second magnetic core, and the third magnetic core are stacked in sequence; the third magnetic core has at least two separation structures, and the at least two separation structures are spaced apart in sequence. Every two adjacent separation structures and the second magnetic core form a mounting hole; each winding is located between the third magnetic core and the second magnetic core, and is wound around the common mode magnetic core and the second magnetic core. Each winding passes through a corresponding mounting hole, and any two adjacent windings are separated by a separation structure.

2. The inverter according to claim 1, characterized in that The third magnetic core includes an upper magnetic core, the at least two partition structures are located between the upper magnetic core and the second magnetic core, the upper magnetic core, each adjacent two partition structures and the second magnetic core all form a mounting hole, and each partition structure is a magnetic column.

3. The inverter according to claim 1, characterized in that Each of the separation structures is a magnetic column, one end of each of the magnetic columns is close to the second magnetic core, the at least two magnetic columns converge at one end away from the second magnetic core, and every two adjacent magnetic columns and the second magnetic core form a mounting hole.

4. The inverter according to any one of claims 1 to 3, characterized in that: The common-mode magnetic core has a first through hole; along the axial direction of the first through hole, the second magnetic core is located on one side of the common-mode magnetic core, and the second magnetic core has a second through hole, which is connected to the first through hole; each of the mounting holes is connected to the second through hole; each of the windings passes through a mounting hole, the second through hole and the first through hole.

5. The inverter according to claim 4, characterized in that: A projection of the second magnetic core along the axial direction falls within the range of the common mode magnetic core.

6. The inverter according to claim 4, characterized in that The projection of the third magnetic core along the axial direction falls within the circumscribed circle of the projections of the at least two windings along the axial direction.

7. The inverter according to any one of claims 1 to 3 or claim 5 or 6, characterized in that: The integrated inductor includes a non-magnetic conductive plate disposed between the common mode magnetic core and the second magnetic core, wherein the non-magnetic conductive plate forms a first air gap; Alternatively, the integrated inductor includes a plurality of non-magnetic conductive pillars disposed between the common mode magnetic core and the second magnetic core, wherein the plurality of non-magnetic conductive pillars form a first air gap; Alternatively, the surface of the common mode magnetic core and / or the surface of the second magnetic core is covered with an insulating layer, and the insulating layer forms a first air gap.

8. The inverter according to claim 7, characterized in that: The first air gap is greater than or equal to 0.5 mm.

9. An integrated inductor, characterized in that: It includes a common-mode magnetic core, a differential-mode magnetic core and at least two windings; the differential-mode magnetic core includes a second magnetic core and a third magnetic core, and the common-mode magnetic core, the second magnetic core and the third magnetic core are stacked in sequence; the third magnetic core has at least two partition structures, and the at least two partition structures are spaced apart in sequence, and every two adjacent partition structures and the second magnetic core participate in forming a mounting hole; each winding is located between the third magnetic core and the second magnetic core, and is wound around the common-mode magnetic core and the second magnetic core, each winding passes through a corresponding mounting hole, and any two adjacent windings are separated by a partition structure.

10. The integrated inductor according to claim 9, characterized in that: The third magnetic core includes an upper magnetic core, the at least two partition structures are located between the upper magnetic core and the second magnetic core, the upper magnetic core, each two adjacent partition structures and the second magnetic core all enclose one mounting hole, and each partition structure is a magnetic column; Alternatively, each of the separation structures is a magnetic column, one end of each of the magnetic columns is close to the second magnetic core, the at least two magnetic columns converge at one end away from the second magnetic core, and every two adjacent magnetic columns and the second magnetic core form a mounting hole.

11. The integrated inductor according to claim 9 or 10, characterized in that: The common-mode magnetic core has a first through hole; along the axial direction of the first through hole, the second magnetic core is located on one side of the common-mode magnetic core, the second magnetic core has a second through hole, and the second through hole is connected to the first through hole; each of the windings passes through the second through hole and the first through hole accordingly.

12. The integrated inductor according to claim 11, characterized in that: The projection of the second magnetic core along the axial direction falls within the range of the common mode magnetic core; and / or the projection of the third magnetic core along the axial direction falls within the circumscribed circle of the projections of the at least two windings along the axial direction.

13. The integrated inductor according to claim 9, 10 or 12, characterized in that: The integrated inductor includes a non-magnetic conductive plate disposed between the common mode magnetic core and the second magnetic core, wherein the non-magnetic conductive plate forms a first air gap; Alternatively, the integrated inductor includes a plurality of non-magnetic conductive pillars disposed between the common mode magnetic core and the second magnetic core, wherein the plurality of non-magnetic conductive pillars form a first air gap; Alternatively, the surface of the common mode magnetic core and / or the surface of the second magnetic core is covered with an insulating layer, and the insulating layer forms a first air gap.

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