Patent Description:
With development of modern industrial technologies, various nonlinear and time-varying power electronic apparatuses such as an inverter are widely used in a power system. However, there is negative effect while industrial production efficiency is improved. Due to an interference electromagnetic field in the inverter, a differential mode current is generated between conducting wires, or a common mode current is generated between a conducting wire and the ground. Both the differential mode current and the common mode current interfere with a load in the power system, and affect a normal operation of the load. Therefore, a filter inductor is usually disposed in the power system. The filter inductor includes a differential mode inductor and a common mode inductor. The differential mode inductor is used to suppress differential mode interference, and the common mode inductor is used to suppress common mode interference. However, as two independent components, the common mode inductor and the differential mode inductor are separately manufactured and independently mounted. Therefore, when the filter inductor is mounted on a circuit board, the filter inductor occupies a large board area, has low power density, and is costly to manufacture separately.

<CIT> describes a modular and reconfigurable electrical power conversion device.

KURM <NPL>" describes a multiport converter for PC-battery systems powering standalone loads.

<NPL>" describes an integrated choke with a certain winding structure, consisting of two cores a toroid and a solenoid.

This application provides an inverter and an integrated inductor, to reduce an occupied area of a filter inductor, improve power density, and reduce costs.

The present invention is defined by the subject-matter of the independent claim.

According to an aspect, this application provides an inverter. The inverter includes a direct current-alternating current conversion circuit and a filter circuit, where the filter circuit is connected to an alternating current side of the direct current-alternating current conversion circuit. The filter circuit includes an integrated inductor. The integrated inductor 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. 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 on the common mode magnetic core and the second magnetic core. The at least two windings are spaced by the third magnetic core.

In this solution, the filter circuit is configured to perform filtering, suppress differential mode resonance, and suppress common mode interference. The integrated inductor is disposable on a circuit board, and the stacking may mean that the common mode magnetic core, the second magnetic core, and the third magnetic core are disposed in sequence in a direction vertical to the circuit board. There is a gap between the third magnetic core and the second magnetic core, and the winding is located in the gap. The third magnetic core may have a plurality of partition structures, and two adjacent windings are spaced by one partition structure. The winding and the common mode magnetic core form a common mode inductor. The winding, the second magnetic core, and the third magnetic core form a differential mode inductor.

In this solution, the common mode magnetic core and the differential mode magnetic core share the winding, to integrate the common mode inductor and the differential mode inductor into one component. This helps save space and reduce costs, and can further reduce a copper loss. Therefore, impact of the copper loss on efficiency of an inverter system is reduced, and efficiency of the integrated inductor is effectively improved. When the integrated inductor is assembled to a circuit board, because the common mode magnetic core and the differential mode magnetic core are stacked, an occupied area of the integrated inductor on the circuit board can be saved, and power density is improved.

In an implementation of this aspect, the third magnetic core and the second magnetic core enclose at least two mounting holes, and each winding correspondingly passes through one of the mounting holes. In this solution, the third magnetic core and the second magnetic core may enclose the at least two mounting holes, so that the differential mode magnetic core having such a structure is reliable and features good mass production. This helps stack the differential mode magnetic core and the common mode magnetic core.

In an implementation of the aspect, the third magnetic core includes at least two magnetic columns and an upper magnetic core. The at least two magnetic columns are located between the upper magnetic core and the second magnetic core. The upper magnetic core, the at least two magnetic columns, and the second magnetic core enclose at least two mounting holes. In this solution, the magnetic column may be directly connected to the upper magnetic core or an air gap is formed. Alternatively, the magnetic column is directly connected to the second magnetic core or an air gap is formed. The winding is located between the upper magnetic core and the second magnetic core, and adjacent windings are spaced by one magnetic column. In this solution, a part of the second magnetic core, any two adjacent magnetic columns, and a part of the upper magnetic core enclose one mounting hole, and form a differential mode magnetic circuit. The differential mode magnetic core having such a structure is simple and reliable, and features good mass production. This helps stack the differential mode magnetic core and the common mode magnetic core.

In an implementation of the aspect, the third magnetic core includes at least two magnetic columns. An end of each magnetic column is close to the second magnetic core, and ends, away from the second magnetic core, of the at least two magnetic columns are converged. The at least two magnetic columns and the second magnetic core enclose at least two mounting holes. In this solution, convergence may mean that ends, away from the second magnetic core, of the magnetic columns are connected to form the air gap, or may mean that the ends, away from the second magnetic core, of the magnetic columns are close to each other to form the air gap. In this solution, the part of the second magnetic core and the any two adjacent magnetic columns enclose one mounting hole, and form a differential mode magnetic circuit. The differential mode magnetic circuit provided in this solution has a simple structure, which helps miniaturize a size of the integrated inductor.

In an implementation of the aspect, the common mode magnetic core has a first through hole, and the second magnetic core is located on a side of the common mode magnetic core in an axial direction of the first through hole. The second magnetic core has a second through hole, and the second through hole is communicated with the first through hole. Each mounting hole is communicated with the second through hole. Each winding correspondingly passes through one of the mounting holes, the second through hole, and the first through hole. In this solution, the common mode magnetic core and the second magnetic core each may be in an annular shape. In this solution, a specific stacked structure of the common mode magnetic core and the differential mode magnetic core is limited. The stacked structure is simple and reliable, and features good mass production. This helps miniaturize the size of the integrated inductor.

In an implementation of the aspect, a projection of the second magnetic core in the axial direction falls within a range of the common mode magnetic core. In this solution, a projection of the second magnetic core in a stacking direction is located within a contour and a boundary of the common mode magnetic core. This saves a projection area of the integrated inductor in the stacking direction, and saves a board area.

In an implementation of the aspect, a projection of the third magnetic core in the axial direction falls within a circumcircle of projections of the at least two windings in the axial direction. In this solution, projections of all windings in the axial direction may be located in a same circle, and a projection of each winding in the axial direction is connected to the circle. The circle may be referred to as a circumcircle. In this solution, the circumcircle determines a maximum outline dimension of the integrated inductor, so that the projection of the third magnetic core in the axial direction does not exceed the circumcircle. This saves the projection area of the integrated inductor in the axial direction, and saves the board area.

In an implementation of the aspect, the integrated inductor includes a non-magnetic plate disposed between the common mode magnetic core and the second magnetic core, and the non-magnetic plate forms a first air gap. Alternatively, the integrated inductor includes a plurality of non-magnetic pillars disposed between the common mode magnetic core and the second magnetic core, and the plurality of non-magnetic pillars form a first air gap. Alternatively, an insulation layer is covered on a surface of the common mode magnetic core and/or a surface of the second magnetic core, and the insulation layer forms a first air gap. In this solution, magnetic circuits of the common mode magnetic core and the differential mode magnetic core are spaced by a first air gap between the common mode magnetic core and the differential mode magnetic core, so that the common mode magnetic circuit and the differential mode magnetic circuit are independent of each other and do not affect each other. This improves an overall anti-saturation capability of the integrated inductor.

In an implementation of the aspect, the first air gap is greater than or equal to <NUM>. When the first air gap is within the value range, a layout of the integrated inductor is compact, occupied mounting space is reduced, and the overall anti-saturation capability of the integrated inductor is optimized.

According to another aspect, this application provides an integrated inductor. The integrated inductor 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. 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 on the common mode magnetic core and the second magnetic core. The at least two windings are spaced by the third magnetic core.

In this solution, the integrated inductor is disposable a circuit board, and the stacking may mean that the common mode magnetic core, the second magnetic core, and the third magnetic core are disposed in sequence in a direction vertical to the circuit board. There is a gap between the third magnetic core and the second magnetic core, and the winding is located in the gap. The third magnetic core may have a plurality of partition structures, and two adjacent windings are spaced by one partition structure. The winding and the common mode magnetic core form a common mode inductor. The winding, the second magnetic core, and the third magnetic core form a differential mode inductor.

In an implementation of this aspect, the third magnetic core and the second magnetic core enclose at least two mounting holes, and each winding correspondingly passes through one of the mounting holes. In this solution, the third magnetic core and the second magnetic core may enclose the at least two mounting holes, so that the differential mode magnetic core having such a structure is reliable and features good mass production. This helps to stack the differential mode magnetic core and the common mode magnetic core.

In an implementation of the aspect, the third magnetic core includes at least two magnetic columns and an upper magnetic core. The at least two magnetic columns are located between the upper magnetic core and the second magnetic core. The upper magnetic core, the at least two magnetic columns, and the second magnetic core enclose at least two mounting holes. In this solution, the magnetic column may be directly connected to the upper magnetic core or an air gap is formed. Alternatively, the magnetic column is directly connected to the second magnetic core or an air gap is formed. The winding is located between the upper magnetic core and the second magnetic core, and adjacent windings are spaced by one magnetic column. In this solution, a part of the second magnetic core, any two adjacent magnetic columns, and a part of the upper magnetic core enclose one mounting hole, and form a differential mode magnetic circuit. The differential mode magnetic core having such a structure is simple and reliable, and has features mass production. This helps to stack the differential mode magnetic core and the common mode magnetic core.

In an implementation of the aspect, the third magnetic core includes at least two magnetic columns. An end of each magnetic column is close to the second magnetic core, and ends of the at least two magnetic columns away from the second magnetic core are converged. The at least two magnetic columns and the second magnetic core enclose at least two mounting holes. In this solution, convergence may mean that ends, away from the second magnetic core, of the magnetic column are connected to form the air gap, or may mean that the ends, away from the second magnetic core, of the magnetic columns are close to each other to form the air gap. In this solution, the part of the second magnetic core and the any two adjacent magnetic columns enclose one mounting hole, and form a differential mode magnetic circuit. The differential mode magnetic circuit provided in this solution has a simple structure, which helps miniaturize a size of the integrated inductor.

In an implementation of the aspect, the common mode magnetic core has a first through hole. and the second magnetic core is located on a side of the common mode magnetic core in an axial direction of the first through hole. The second magnetic core has a second through hole, and the second through hole is communicated with the first through hole. Each mounting hole is communicated with the second through hole. Each winding correspondingly passes through one of the mounting holes, the second through hole, and the first through hole. In this solution, the common mode magnetic core and the second magnetic core each may be in an annular shape. In this solution, a specific stacked structure of the common mode magnetic core and the differential mode magnetic core is limited. The stacked structure is simple and reliable, and features good mass production. This helps miniaturize the size of the integrated inductor.

In an implementation of the aspect, the third magnetic core may have a rotationally symmetric structure. In this solution, the third magnetic core is limited to the rotationally symmetric structure, so that internal components of the third magnetic core can be uniformly distributed, and the structure is more appropriate, to facilitate cooperation with the winding. Therefore, a layout of the integrated inductor is compact, occupied mounting space is reduced, and working performance of the differential mode magnetic circuit is ensured.

In an implementation of the aspect, the integrated inductor includes a non-magnetic plate disposed between the common mode magnetic core and the second magnetic core, and the non-magnetic plate forms a first air gap. Alternatively, the integrated inductor includes a plurality of non-magnetic pillars disposed between the common mode magnetic core and the second magnetic core, and the plurality of non-magnetic pillars form a first air gap. Alternatively, an insulation layer is covered on a surface of the common mode magnetic core and/or a surface of the second magnetic core, and the insulation layer forms a first air gap. In this solution, magnetic circuits of the common mode magnetic core and the differential mode magnetic core are spaced by the first air gap between the common mode magnetic core and the differential mode magnetic core, so that the common mode magnetic circuit and the differential mode magnetic circuit are independent of each other and do not affect each other. This improves an overall anti-saturation capability of the integrated inductor.

In an implementation of the aspect, a second air gap is formed between the second magnetic core and the third magnetic core. In this solution, both the second magnetic core and the third magnetic core are a part of the differential mode magnetic core, and the second air gap is formed between the second magnetic core and the third magnetic core, that is, there is an air gap inside the differential mode magnetic core. The second air gap can improve magnetic energy of the differential mode magnetic core.

In an implementation of the aspect, a third air gap is formed between each magnetic column and the upper magnetic core. In this solution, both the magnetic column and the upper magnetic core are a part of the differential mode magnetic core, and the third air gap is formed between the magnetic column and the upper magnetic core, that is, there is an air gap inside the differential mode magnetic core. The third air gap can improve the magnetic energy of the differential mode magnetic core.

The integrated inductor may be applied in a circuit board component. The circuit board component includes a circuit board and the integrated inductor. A winding of the integrated inductor is connected to the circuit board. In this solution, when the winding of the integrated inductor is mounted on the circuit board, board space in a first direction is small, so that mounting space is saved for other components on the circuit board, and a component layout of the circuit board is more appropriate.

The following are explanations of some terms.

Parallel: Parallel defined in embodiments of this application is not limited to absolute parallel. The definition of the parallel may be understood as basic parallel, allowing for non-absolute parallel affected by factors such as an assembly tolerance, a design tolerance, and a structural flatness.

Vertical: Vertical defined in embodiments of this application is not limited to an absolute vertical intersection (an included angle is <NUM> degrees) relationship, allowing for a non-absolute vertical intersection relationship affected by factors such as an assembly tolerance, a design tolerance, and a structural flatness. An error within a small angle range is allowed. For example, a relationship within an assembly error range of <NUM> degrees to <NUM> degrees may be understood as a vertical relationship.

The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating a quantity of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the features.

The following describes solutions of this application based on embodiments.

An inverter is widely used in a power supply or power control scenario such as photovoltaic power generation or a frequency converter. When differential mode interference and common mode interference in the scenario have adverse impact on a circuit system, a filter circuit is usually used to filter the interference. A common mode signal is a signal with an equal amplitude and a same phase. A differential mode signal is a signal with an equal amplitude and an opposite phase. In a closed circuit, a common mode interference signal has an equal amplitude and a same direction on two conducting wires, which is essentially interference produced by a voltage difference between two wires and a ground cable in the closed circuit. A differential mode interference signal has an equal amplitude and an opposite phase between two conducting wires, which is essentially interference produced between the two wires.

<FIG> is a schematic diagram of a structure of a circuit framework of a conventional inverter. As shown in <FIG>, the inverter may include a direct current-alternating current (DC-AC) conversion circuit and a filter circuit. The filter circuit is connected to an alternating current side of the direct current-alternating current conversion circuit, and the direct current-alternating current (DC-AC) conversion circuit is connected to an alternating current grid (AC GRID) through the filter circuit. For example, the filter circuit may include an inductor L1, a filter capacitor C, a differential mode inductor L2, and a common mode inductor L_cm. For example, the inductor L1 and the filter capacitor C may filter a square wave output by the DC-AC conversion circuit into a sine wave. The differential mode inductor L2 may be configured to filter and suppress differential mode resonance, and the common mode inductor L_cm may be configured to suppress common mode interference.

In the foregoing solution, the common mode inductor L_cm and the differential mode inductor L2 in the inverter are independent of each other, and are separately mounted as two independent inductor elements. The solution has the following defects: When two inductors are mounted on a circuit board, a board area occupied by the two inductors is large, power density of the circuit board is small, and separate manufacturing costs of the two inductors are high.

In view of this, as shown in <FIG>, the solution in this embodiment of this application provides an inverter. Consistent with the foregoing conventional solution, the inverter includes a direct current-alternating current conversion circuit and a filter circuit. The filter circuit is connected to an alternating current side of the direct current-alternating current conversion circuit, and the direct current-alternating current conversion circuit may be connected to a grid through the filter circuit. For example, the filter circuit may include an inductor L1 and a filter capacitor C. Different from the foregoing conventional solution, the filter circuit in this embodiment of this application includes an integrated inductor L0. The integrated inductor L0 integrates a common mode inductor and a differential mode inductor into a component, and the common mode inductor and the differential mode inductor are stacked in sequence. In this way, a volume and occupied board area can be reduced, costs can be reduced, and power density can be further improved. The following describes in detail.

As shown in <FIG>, an embodiment of this application provides an inverter <NUM>. The inverter <NUM> may include a circuit board component <NUM> and a housing <NUM>. The housing <NUM> surrounds an outer side of the circuit board component <NUM>, to accommodate and protect the circuit board component <NUM>. The circuit board component <NUM> may include electronic components such as an integrated inductor <NUM>, a circuit board <NUM>, and a control chip <NUM>. Both the integrated inductor <NUM> and the control chip <NUM> may be disposed on the circuit board <NUM>, and positions of the integrated inductor <NUM> and the control chip <NUM> on the circuit board <NUM> may be determined as required. This is not limited in this embodiment of this application.

As shown in <FIG>, <FIG>, the integrated inductor <NUM> may include a first magnetic core <NUM>, an air gap plate <NUM>, a differential mode magnetic core <NUM>, and windings <NUM>.

As shown in <FIG> and <FIG>, the first magnetic core <NUM> may have an annular structure. The first magnetic core <NUM> has a first through hole 1a, and the first through hole 1a passes through the first magnetic core <NUM> in an axial direction of the first magnetic core <NUM>. An axial direction of the first through hole 1a is a first direction. Refer to <FIG>. An extension direction of an arrow D is the first direction. In this embodiment of this application, the first magnetic core <NUM> has an annular structure. In another embodiment, the first magnetic core <NUM> is not limited to the annular structure, and may alternatively be another polygonal ring structure. In this implementation of this application, the first magnetic core <NUM> may be made of magnetic materials such as a ferrite and an amorphous strip.

As shown in <FIG> and <FIG>, the air gap plate <NUM> has an annular plate structure with a through hole. An air gap plate <NUM> is located on a side of the first magnetic core <NUM> in the first direction. The air gap plate <NUM> is attached to the first magnetic core <NUM>, and the first through hole 1a is connected to the through hole of the air gap plate <NUM>. The air gap plate <NUM> may be made of non-magnetic plates such as an epoxy plate and a polyvinyl chloride (PVC) plate.

The following describes a structure of the differential mode magnetic core <NUM> and a position relationship among the differential mode magnetic core <NUM>, the first magnetic core <NUM>, and the air gap plate <NUM>.

As shown in <FIG> and <FIG>, the differential mode magnetic core <NUM> may include a second magnetic core <NUM> and a third magnetic core.

As shown in <FIG> and <FIG>, the second magnetic core <NUM> may have an annular structure. The second magnetic core <NUM> has a second through hole 41a, and the second through hole 41a passes through the second magnetic core <NUM> in an axial direction of the second magnetic core <NUM>. A side surface of the second magnetic core <NUM> is a first surface 41b of the second magnetic core <NUM>. The second magnetic core may be made of magnetic materials such as a silicon steel magnetic material and an amorphous strip. In this embodiment of this application, the second magnetic core <NUM> has an annular structure. In another embodiment, the second magnetic core <NUM> is not limited to the annular structure, and may alternatively be another polygonal ring structure.

As shown in <FIG> and <FIG>, the second magnetic core <NUM> is located, in the first direction, on a side that is of the air gap plate <NUM> and that is away from the first magnetic core <NUM>, so that the air gap plate <NUM> is located between the first magnetic core <NUM> and the second magnetic core <NUM>, the first surface 41b of the second magnetic core <NUM> is away from the air gap plate <NUM>, and the first direction is approximately vertical to the first surface 41b.

In the first direction, a spacing between the first magnetic core <NUM> and the second magnetic core <NUM> is a first air gap. In this embodiment of this application, the first air gap may be formed by an air gap plate <NUM> between the second magnetic core <NUM> and the first magnetic core <NUM>.

In another implementation, an insulation layer (for example, the insulation layer may be a housing that wraps an outer surface of the second magnetic core <NUM> and/or an outer surface first magnetic core <NUM>) may be disposed on a surface of the second magnetic core <NUM> and/or a surface of the first magnetic core <NUM>, to form the first air gap.

Alternatively, the first air gap may be formed by forming a gap between the first magnetic core <NUM> and the second magnetic core <NUM> (there is air in the gap). A plurality of support columns with low magnetic permeability may be disposed in the gap, to support the first magnetic core <NUM> and the second magnetic core <NUM>.

Alternatively, the first air gap may be formed by filling another material with low magnetic permeability between the first magnetic core <NUM> and the second magnetic core <NUM>. The material with low magnetic permeability is filled in the gap between the first magnetic core <NUM> and the second magnetic core <NUM>.

In this implementation of this application, a size of a circumcircle of the second magnetic core <NUM> may be basically the same as a size of a circumcircle of the first magnetic core <NUM>. In another implementation, a shape and a size of the second magnetic core <NUM> may be designed as required, provided that a projection of the second magnetic core in the first direction falls within a projection of the first magnetic core <NUM>.

The third magnetic core may have a rotationally symmetric structure, and a center of the rotationally symmetric structure may be the axial direction of the second magnetic core <NUM>. A projection of the third magnetic core in the first direction falls within a circumcircle of projections of the windings <NUM> in the first direction, for example, falls within the first surface 41b. The third magnetic core and the second magnetic core <NUM> enclose at least two mounting holes. Enclosing the mounting holes may mean that the second magnetic core <NUM> is directly connected to the third magnetic core to form the mounting hole, or may mean that there is a small gap between the second magnetic core <NUM> and the third magnetic core, which may still be considered as enclosing the mounting hole in a macro sense. An axial direction of each mounting hole intersects with the first direction. For example, the axial direction of the mounting hole is vertical to the first direction.

In an implementation, the third magnetic core may include a magnetic column <NUM> and an upper magnetic core <NUM>.

As shown in <FIG> and <FIG>, the magnetic column <NUM> may have a column structure. The magnetic column <NUM> has a second surface 42a and a third surface 42b that are opposite to each other. The second surface 42a and/or the third surface 42b may be a plane or a curved surface. The magnetic column <NUM> may be made of magnetic materials such as a silicon steel magnetic material and an amorphous strip. There may be a plurality of magnetic columns <NUM>. In this implementation of this application, there may be three magnetic columns <NUM>, configured to generate a three-phase differential mode inductor. In another implementation, a quantity of magnetic columns <NUM> may be designed as required.

As shown in <FIG>, <FIG>, and <FIG>, the three magnetic columns <NUM> are located, in the first direction, on a side of the second magnetic core <NUM> having the first surface 41b, and the three magnetic columns <NUM> are uniformly distributed at intervals around the second through hole 41a. Second surfaces 42a of the magnetic columns <NUM> face an inner side of the second magnetic core <NUM>, and third surfaces 42b of the magnetic column <NUM> face the outer surface of the second magnetic core <NUM>. At least a part of projections of the magnetic columns <NUM> in the first direction falls within the first surface 41b. For example, the projections of the magnetic columns <NUM> in the first direction may completely fall within the first surface 41b. When the second surface 42a and the third surface 42b are planes, both the second surface 42a and the third surface 42b are vertical to the first surface 41b. When the second surface 42a and the third surface 42b are cambered surfaces, buses of the second surface 42a and the third surface 42b each are approximately vertical to the first surface 41b, and the buses of the second surface 42a and the third surface 42b may be a moving line for forming any one of the second surface 42a and the third surface 42b. A second air gap may be formed between each magnetic column <NUM> and the second magnetic core <NUM>, and a value range of the second air gap may be <NUM> to <NUM>. For example, the second air gap may be formed by using an air gap plate or glue. The differential mode magnetic core <NUM> and the integrated inductor <NUM> have corresponding magnetic performance by disposing the second air gap. In another embodiment, there may be no second air gap.

As shown in <FIG>, <FIG>, the upper magnetic core <NUM> may have an annular structure. The upper magnetic core <NUM> may be made of magnetic materials such as a silicon steel magnetic material, an amorphous strip, and a powdered iron core magnetic material. The upper magnetic core <NUM> is located on a side that is of the magnetic column <NUM> and that is away from the second magnetic core <NUM>, and the upper magnetic core <NUM> is approximately parallel to the second magnetic core <NUM>. A third air gap is formed between the upper magnetic core <NUM> and each magnetic column <NUM>, and a value range of the third air gap may be <NUM> to <NUM>. For example, the third air gap may be formed by using an air gap plate or glue. The differential mode magnetic core <NUM> and the integrated inductor <NUM> have better magnetic performance by disposing the third air gap. In another embodiment, there may be no third air gap.

As shown in <FIG>, a projection of the upper magnetic core <NUM> in the first direction falls within a circumcircle of projections of three windings <NUM> in the first direction (the following continues to describe assembly and cooperation of the three windings <NUM> with the first magnetic core <NUM>, the second magnetic core <NUM>, and the magnetic column <NUM>).

In this embodiment of this application, the upper magnetic core <NUM> may have an annular structure whose shape and size are approximately the same as those of the second magnetic core <NUM>. Different from the foregoing embodiment, in another embodiment, the upper magnetic core is not limited to the annular structure, and may alternatively have another closed structure (including but not limited to a closed square annular structure). Alternatively, the upper magnetic core may include a plurality of sub magnetic cores that are distributed at intervals, and each sub magnetic core corresponds to two magnetic columns.

As shown in <FIG>, the first magnetic core <NUM>, the second magnetic core <NUM>, the magnetic column <NUM>, and the upper magnetic core <NUM> are stacked in sequence in the first direction. The first magnetic core <NUM> may be a common mode magnetic core, and the second magnetic core <NUM>, the three magnetic columns <NUM>, and the upper magnetic core <NUM> jointly form the differential mode magnetic core <NUM>. In the differential mode magnetic core <NUM>, as shown in <FIG>, a part of the second magnetic core <NUM>, any two adjacent magnetic columns <NUM>, and a part of the upper magnetic core <NUM> enclose a mounting hole 4a. An axial direction of the mounting hole 4a intersects with the first direction. For example, the axial direction of the mounting hole 4a is vertical to the first direction. In this embodiment of this application, because there are three magnetic columns <NUM>, three mounting holes 4a are formed.

In another implementation, the third magnetic core may include a magnetic column. A shape and a material of the magnetic column may be approximately the same as those of the magnetic column <NUM> in the foregoing implementation, and there may be a plurality of magnetic columns. The plurality of magnetic columns are all located, in the first direction, on a side that is of the second magnetic core <NUM> and that is away from the first magnetic core <NUM>, and are uniformly distributed around the second through hole 41a. An end of each magnetic column is close to the second magnetic core, and the ends of the plurality of magnetic columns are converged (convergence may mean that ends of the plurality of magnetic columns are connected to each other to form a specific air gap, or may mean that ends of the plurality of magnetic columns are close to each other to form a specific air gap). The second air gap is formed between each magnetic column and the second magnetic core. The value range and a forming manner of the second air gap may be approximately the same as those of the second air gap in the foregoing implementation. In this implementation, the first magnetic core <NUM>, the second magnetic core <NUM>, and the plurality of magnetic columns are stacked in sequence in the first direction. The first magnetic core <NUM> may be a common mode magnetic core, and the second magnetic core <NUM> and the plurality of magnetic columns jointly form a differential mode magnetic core. In the differential mode magnetic core, a part of the second magnetic core <NUM> and any two adjacent magnetic columns enclose a mounting hole. An axial direction of the mounting hole intersects with the first direction. For example, the axial direction of the mounting hole may be vertical to the first direction.

The foregoing mainly describes a position relationship among the common mode magnetic core, the differential mode magnetic core <NUM>, and the air gap plate <NUM> in the integrated inductor <NUM>. The following describes a structure of the winding <NUM>, and assembly and cooperation of the winding <NUM> with the differential mode magnetic core <NUM> and the first magnetic core <NUM>.

In this embodiment of this application, the winding <NUM> is formed by enclosing a line of which an outer surface is covered with an insulation layer. The winding <NUM> may be, for example, an enameled wire or a film-clad wire. As shown in <FIG>, the winding <NUM> includes a coil body <NUM> and a wiring pin <NUM> that are connected to each other. The coil body <NUM> has a through hole enclosed by a coil. In an implementation, there may be two wiring pins <NUM> that are respectively located on two sides of the coil body <NUM> and are approximately tangent to the coil body <NUM>. In other implementations, the wiring pins <NUM> may be located on a same side of the coil body <NUM>. If distribution manners of the wiring pins <NUM> on the coil body <NUM> are different, mounting areas of the integrated inductor <NUM> on the circuit board <NUM> are different. Therefore, positions of the wiring pins <NUM> may be designed as required. A quantity of windings <NUM> corresponds to the quantity of magnetic columns <NUM>. There are at least two windings <NUM>, for example, there may be three windings <NUM>. A quantity of turns of a coil of each winding <NUM> is the same, and a winding direction of each winding <NUM> is the same.

As shown in <FIG>, <FIG>, and <FIG>, the coil body <NUM> of each winding <NUM> passes through the first through hole 1a, the through hole of the air gap plate <NUM>, the second through hole 41a, and the mounting hole 4a, so that each winding <NUM> is wound around the first magnetic core <NUM>, the air gap plate <NUM>, and the differential mode magnetic core. A through hole of each coil body <NUM> accommodates a part of the first magnetic core <NUM>, a part of the air gap plate <NUM>, and the part of the second magnetic core <NUM>. The wiring pin <NUM> of the winding <NUM> is located, in the first direction, on a side that is of the first magnetic core <NUM> and that is away from the second magnetic core <NUM>. As shown in <FIG>, the three windings <NUM> may be uniformly distributed on the first magnetic core <NUM>, a gap is formed between adjacent windings, and a spacing is formed between every two windings <NUM>.

As shown in <FIG>, because the first magnetic core <NUM> is a closed annular magnetic core, the first magnetic core <NUM> forms a closed common mode magnetic circuit A (<FIG> only shows a part of the common mode magnetic circuit A, and does not show a complete common mode magnetic circuit A), and the first magnetic core <NUM> and each winding <NUM> form a common mode inductor. The common mode inductor is configured to suppress common mode interference. As an example rather than a limitation, common mode inductance formed between the winding <NUM> and the first magnetic core <NUM> may be adjusted by adjusting the quantity of turns of any winding <NUM> or by adjusting an area of a cross section of the first magnetic core <NUM>.

As shown in <FIG>, the differential mode magnetic core <NUM> forms three differential mode magnetic circuits B in total (<FIG> shows only two differential mode magnetic circuits B, but does not shows all differential mode magnetic circuits B). The part of the second magnetic core <NUM>, the any two adjacent magnetic columns <NUM>, and the part of the upper magnetic core <NUM> form one differential mode magnetic circuit B. Each magnetic column <NUM> is used as a common magnetic core of two adjacent differential mode magnetic circuits B. The differential mode magnetic core <NUM> and the winding <NUM> wound on the differential mode magnetic core <NUM> form a differential mode inductor, to suppress a differential mode current. The magnetic column <NUM> is used as the common magnetic core, so that a volume of the differential mode magnetic core <NUM> can be reduced. This solution facilitates assembly, has higher flexibility in an assembly process, and improves assembly efficiency.

The first air gap between the differential mode magnetic core <NUM> and the first magnetic core <NUM> can isolate the differential mode magnetic core <NUM> and the first magnetic core <NUM>, so 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.

In this embodiment, the second air gap and the third air gap inside the differential mode magnetic core <NUM> can improve stability of a magnetic field of the integrated inductor <NUM>, so that the integrated inductor <NUM> has better magnetic performance. In other embodiments, the second air gap and/or the third air gap may not be disposed.

In the foregoing implementation, the first magnetic core <NUM> and the second magnetic core <NUM> each have a closed annular structure, which is only an example. Actually, structures of magnetic cores of the first magnetic core <NUM> and the second magnetic core <NUM> may be set in any shape as required, and are not limited to the closed annular structure.

In the foregoing implementation, there are three windings <NUM> and three magnetic columns <NUM>, which are used to form a three-phase integrated inductor. In other implementations, four windings <NUM> and four magnetic columns <NUM> may form a three-phase four-wire integrated inductor. Alternatively, two windings <NUM> and two magnetic columns <NUM> may form a two-phase integrated inductor, and the two-phase integrated inductor may be, for example, used as a single-phase energy storage inverter.

With reference to <FIG> and <FIG>, an inductor mounting area <NUM> is disposed on the circuit board <NUM>, and a pad <NUM> is disposed in the inductor mounting area <NUM>. The inductor mounting area <NUM> is configured to position and mount the integrated inductor <NUM>. A contour of the inductor mounting area <NUM> is basically the same as a projection of an outer contour of the integrated inductor <NUM> in the first direction. Therefore, an area of the inductor mounting area <NUM> is board space of the integrated inductor <NUM> on the circuit board <NUM>. The pad <NUM> corresponds to the wiring pin <NUM> of the winding <NUM>, so that the wiring pin <NUM> is welded on the pad <NUM>. A position of the pad <NUM> in the inductor mounting area <NUM> depends on a position of the wiring pins <NUM>. The position of the pad <NUM> may be designed as required, and this is not limited herein.

A conventional common mode inductor and a conventional differential mode inductor are usually used as two components, and are separately manufactured and mounted. Therefore, a board area on the circuit board is large and power density is small.

However, in this embodiment of this application, the integrated inductor <NUM> integrates differential mode inductor and the common mode inductor are integrated, so that a volume of the integrated inductor <NUM> is greatly reduced, the board area on the circuit board <NUM> is reduced, the power density is improved, and costs are reduced. In addition, the differential mode magnetic core <NUM> and the first magnetic core <NUM> share the three-phase winding <NUM>. On the premise of ensuring that the differential mode current and the common mode current are suppressed, usage of the winding <NUM> can be reduced, and a copper loss can be effectively reduced, so that impact of the copper loss on efficiency of an inverter system is reduced, and efficiency of the integrated inductor <NUM> is effectively improved. In addition, in this embodiment of this application, a first air gap is formed between the differential mode magnetic core <NUM> and the first magnetic core <NUM>, so that the differential mode magnetic circuit B and the common mode magnetic circuit A are independent of each other, to prevent coupling. In a case of a large current, a magnetic flux of the differential mode magnetic core <NUM> does not occupy a magnetic flux of the first magnetic core, to oversaturate the differential mode magnetic core <NUM>. Therefore, the integrated inductor <NUM> provided in this embodiment of this application can withstand a larger current, and has an excellent anti-magnetic saturation capability.

In addition, in this embodiment of this application, the integrated inductor <NUM> is disposed in a stacking manner, projections of magnetic cores of the differential mode magnetic core <NUM> in the first direction have a large overlapping area with projections of the first magnetic core <NUM> in the first direction, and the magnetic column <NUM> of the differential mode magnetic core <NUM> is a common magnetic core shared by adjacent differential mode magnetic circuits. These designs can reduce a board area occupied by the magnetic column <NUM> in the first direction. Therefore, when the integrated inductor <NUM> is mounted on the circuit board <NUM>, the area of the inductor mounting area <NUM> can be greatly reduced, mounting space can be reserved for other components on the circuit board <NUM>, and a volume of the circuit board component <NUM> can also be reduced.

Claim 1:
An integrated inductor (L<NUM>) comprising a common mode magnetic core (<NUM>), a differential mode magnetic core (<NUM>), and at least two windings (<NUM>); the differential mode magnetic core (<NUM>) comprises a second magnetic core (<NUM>) and a third magnetic core (<NUM>, <NUM>), wherein
; the common mode magnetic core (<NUM>), the second magnetic core (<NUM>), and the third magnetic core are stacked in sequence in a first direction; each winding (<NUM>) is located between the third magnetic core and the second magnetic core (<NUM>), and is wound on the common mode magnetic core (<NUM>) and the second magnetic core (<NUM>); and the at least two windings (<NUM>) are spaced by the third magnetic core;
wherein the third magnetic core and the second magnetic core (<NUM>) enclose at least two mounting holes (4a) and each winding (<NUM>) correspondingly passes through one of the mounting holes; wherein an axial direction of the at least two mounting holes intersect with the first direction;
wherein the common mode magnetic core (<NUM>) has a first through hole (1a); the second magnetic core (<NUM>) is located on a side of the common mode magnetic core (<NUM>) in an axial direction of the first through hole (1a) corresponding to the first direction, wherein the second magnetic core (<NUM>) has a second through hole (41a), and the second through hole (41a) is communicated with the first through hole (1a); each mounting hole is communicated with the second through hole (41a); and each winding (<NUM>) correspondingly passes through one of the mounting holes, the second through hole (41a), and the first through hole (1a).