Patent Description:
A magnetic integrated device is a device integrating a plurality of discrete devices (such as an inductor and a transformer) in a power conversion circuit.

The magnetic integrated device includes a magnetic core, an inductor winding wound around the magnetic core, and a transformer winding wound around the magnetic core. The transformer winding generally includes three windings: a direct current bus side winding, a high-voltage winding, and a low-voltage winding.

Because the magnetic integrated device has a relatively large quantity of windings and occupies relatively large space, a volume of the magnetic integrated device is relatively large. <CIT> relates to a transformer, in particular for an energy converter, comprising a primary winding and a secondary winding established on a magnetic circuit capable of channelling the flow from the primary winding to the secondary winding, and comprising at least three branches, called lateral and central, connected to each other, at each end, by two bars. According to the invention, the primary and secondary windings are arranged around two separate branches forming with the cross-members a closed circuit, and the other branch comprises an air gap of predetermined adjustable thickness adapted to channel the magnetic leakage flux of the transformer. In addition, a closed outer coil is disposed about the magnetic circuit. <CIT> discloses in an integrated magnetic component for a switched mode power converter, in particular for a soft switching converter and/or for an LLC resonant converter, according to the invention, which comprises two magnetic cores forming an <NUM>-shaped core structure and at least two first electric winding wires, wherein a first magnetic core is an E-core, at least one of the first electric winding wires is wound on a flange of the E-core. In <CIT>, a flyback converter is provided which can have multiple interleaved flyback converters with flyback transformers integrated with a common magnetic core. The flyback converters connected in series on a primary side and in parallel on a secondary side of the flyback transformers. The legs of the flyback transformers can be provided with a gap, such as an air gap, while being formed as part of an integrated magnetic structure. <CIT> discloses a resonant converter comprises a resonant circuit, wherein the resonant circuit comprises a first resonant capacitor, an integrated magnetic component and a second resonant capacitor, an integrated magnetic component and a second resonant capacitor, a first winding comprises a first winding part and a second winding part, a second winding comprises a third winding part and a fourth winding part, the first winding part is wound around a first magnetic post and a fourth magnetic post, the second winding part is wound around a second magnetic post and a fifth magnetic post, the third winding part is wound around the first magnetic post and the fourth magnetic post, and the fourth winding part is wound around the second magnetic post and the fifth magnetic post. In <CIT>, a thin film inductor includes a thin film magnetic core. The thin film magnetic core includes a plurality of magnetic cylinders, a first end portion, and a second end portion. The plurality of magnetic cylinders are all rod-shaped and are separated from each other. One end of each magnetic cylinder is in contact with the first end portion, and the other end thereof is in contact with the second end portion. <CIT> discloses a magnetic integrated device comprising: a first magnetic core base and a second magnetic core base that are parallel and a first magnetic core column, a second magnetic core column, and a third magnetic core column that are located between the first magnetic core base and the second magnetic core base; and a first winding, a second winding, and a third winding are wound on the first magnetic core column, the second magnetic core column, and the third magnetic core column respectively in a same manner to form a closed magnetic flux loop. <CIT> discloses a LLC transformer, its implementation method, and magnetic core component. The LLC transformer includes a skeleton, a storage space, an inner baffle, a first side baffle and a second side baffle.

This application provides a magnetic integrated device to resolve a problem in a related technology that a volume of the magnetic integrated device is relatively large. Technical solutions are as follows.

According to the present invention, a magnetic integrated device is provided, including a magnetic core, a first transformer winding, and a second transformer winding, where.

Optionally, the magnetic integrated device may further include a third transformer winding, where the third transformer winding passes through the window and is wound around the magnetic core. Correspondingly, the magnetic integrated device may be applied to a three-port power conversion circuit.

Optionally, the third transformer winding and the second transformer winding are wound in a laminated manner.

A winding manner of winding in the laminated manner can reduce occupied space of the transformer windings. This can effectively reduce the volume of the magnetic integrated device. In addition, the winding manner can ensure that the third transformer winding and the second transformer winding are tightly coupled.

Optionally, the third transformer winding may be flat, and the third transformer winding may cover a surface of the second transformer winding, for example, a part of the surface of the second transformer winding, and a wiring terminal of the second transformer winding is not covered by the third transformer winding, to facilitate connection to an external circuit.

Optionally, both a quantity of turns of the first transformer winding and a quantity of turns of the second transformer winding are greater than a quantity of turns of the third transformer winding.

To be specific, the third transformer winding may be a winding configured to connect to an auxiliary battery with a relatively low voltage. One of the first transformer winding and the second transformer winding may be configured to connect to a direct current bus, and the other transformer winding may be configured to connect to a power battery.

Optionally, both a wire width of the first transformer winding and a wire width of the second transformer winding are less than a wire width of the third transformer winding.

Setting the wire width of the third transformer winding to a relatively large value can reduce resistance of the third transformer winding. This effectively reduces a voltage drop of the third transformer winding.

The second magnet may be a U-shaped magnet on which the groove is formed, and no groove is formed on the first magnet.

Optionally, a quantity of turns of each transformer winding wound around the first magnet may be equal to a quantity of turns of each transformer winding wound around the second magnet. This ensures symmetry of an overall structure of the magnetic integrated device.

Optionally, the magnetic core may further be an integrated part disposed with a through groove, and the through groove is formed as the window.

Optionally, one end of the magnetic core is disposed with one or more second air gaps, and the second air gap is connected to the window.

By disposing the second air gap on the magnetic core, on one hand, a magnetic permeability of the magnetic core can be reduced, and on the other hand, a magnetic saturation phenomenon under a large alternating current signal or a direct current bias can be avoided, to better control inductance of the magnetic integrated device.

Optionally, the window may be a rectangular window.

According to another aspect not claimed, a power conversion circuit is provided. The power conversion circuit may include the magnetic integrated device provided in the foregoing aspect.

In the magnetic integrated device, a first transformer winding may be connected to a first port of the power conversion circuit, a second transformer winding may be connected to a second port of the power conversion circuit, and the first transformer winding and the second transformer winding are capable of transferring energy to each other through electromagnetic mutual inductance.

Optionally, the power conversion circuit may further include a third transformer winding passing through a window and wound around a magnetic core, where
the third transformer winding is connected to a third port of the power conversion circuit, the third transformer winding and the first transformer winding are capable of transferring energy to each other through electromagnetic mutual inductance, and the third transformer winding and the second transformer winding are capable of transferring energy to each other through electromagnetic mutual inductance.

In conclusion, the embodiments of this application provide a magnetic integrated device. The two transformer windings in the magnetic integrated device may be separated and wound, and the first air gap is formed at separation. The magnetic line may pass through the first air gap to form the leakage inductance, and the leakage inductance may be equivalent to the resonant inductance in the power conversion circuit. Therefore, there is no need to separately dispose the inductor winding in the magnetic integrated device. This effectively reduces the volume and the weight of the magnetic integrated device.

The following describes in detail a magnetic integrated device provided in embodiments of this application with reference to accompanying drawings.

<FIG> is a schematic structural diagram of a charger according to an unclaimed embodiment. As shown in <FIG>, the charger <NUM> may include an alternating current/direct current (AC/DC) conversion circuit <NUM> and a power conversion circuit <NUM>. The power conversion circuit <NUM> may also be referred to as a DCDC power converter. One end of the AC/DC may be connected to an alternating current power supply, the other end may be connected to a direct current bus, and the direct current bus is connected to the power conversion circuit <NUM>.

To improve power density, as shown in <FIG>, the DCDC power converter <NUM> used in the charger <NUM> may be a three-port DCDC power converter. Three ports of the DCDC power converter <NUM> may be respectively configured to connect to the direct current bus, a power battery <NUM>, and an auxiliary battery <NUM>, and the DCDC power converter <NUM> can convert power between any two ports. The power battery <NUM> may be configured to supply power to a drive motor of a power driven device. A voltage of the power battery <NUM> is relatively high, and is generally <NUM> V to <NUM> V. Therefore, the power battery <NUM> may also be referred to as a high-voltage battery. The auxiliary battery <NUM> may be configured to supply power to another power driven device (for example, an electronic braking system, a dashboard, and a light control system of an electric vehicle) in the power driven device. A voltage of the auxiliary battery <NUM> is relatively low, and is generally <NUM> V to <NUM> V. Therefore, the auxiliary battery <NUM> may also be referred to as a low-voltage battery.

The DCDC power converter <NUM> can convert power between any two ports. Therefore, as shown in <FIG>, the charger <NUM> integrated with the DCDC power converter <NUM> can implement bidirectional power supply between the alternating current power supply and the power battery <NUM>. Alternatively, as shown in <FIG>, the charger <NUM> may implement bidirectional power supply between the alternating current power supply and the auxiliary battery <NUM>. Alternatively, as shown in <FIG>, the charger <NUM> may implement bidirectional power supply between the power battery <NUM> and the auxiliary battery <NUM>. Alternatively, as shown in <FIG>, the charger <NUM> may implement that the alternating current power supply supplies power to both the power battery <NUM> and the auxiliary battery <NUM>. Alternatively, as shown in <FIG>, the charger <NUM> may implement that the auxiliary battery <NUM> supplies power to both the alternating current power supply and the power battery <NUM>. Alternatively, as shown in <FIG>, the charger <NUM> may implement that the power battery <NUM> supplies power to both the alternating current power supply and the auxiliary battery <NUM>.

In this unclaimed embodiment, to improve power conversion efficiency and power density of the DCDC power converter <NUM>, the DCDC power converter <NUM> may be a resonant or quasi-resonant three-port DCDC power converter. In addition, to further reduce a size of a device, improve power density, improve an inter-adjustment feature of the power converter, and improve a voltage stabilizing capability of the power converter, a resonant inductor and a transformer in the resonant or quasi-resonant three-port DCDC power converter may be implemented by using a magnetic integrated device.

Optionally, the charger <NUM> provided in this unclaimed embodiment may be an on-board charger (OBC) applied to the electric vehicle. Alternatively, the charger <NUM> may be further applied to another power driven device, for example, a sweeping robot.

<FIG> is a schematic structural diagram of a magnetic integrated device according to an unclaimed embodiment of this application. The magnetic integrated device may be applied to a power conversion circuit, for example, the power conversion circuit <NUM> shown in any one of <FIG>. Referring to <FIG>, the magnetic integrated device includes a magnetic core <NUM>, a first transformer winding <NUM>, and a second transformer winding <NUM>.

A window <NUM> is disposed in the magnetic core <NUM>, and the first transformer winding <NUM> and the second transformer winding <NUM> respectively pass through the window <NUM> and are wound around the magnetic core <NUM>. For example, as shown in <FIG>, the window <NUM> may be a through groove disposed in the magnetic core <NUM>.

The first transformer winding <NUM> and the second transformer winding <NUM> are separated and wound on the magnetic core <NUM>, and a first air gap 10a is formed at separation.

A magnetic line generated by the first transformer winding <NUM> and a magnetic line generated by the second transformer winding <NUM> may pass through the first air gap 10a to form leakage inductance, and the leakage inductance may be equivalent to resonant inductance in the power conversion circuit. Therefore, there is no need to separately dispose an inductor winding in the magnetic integrated device. This effectively reduces a volume and a weight of the magnetic integrated device.

For example, <FIG> is an equivalent circuit diagram of a magnetic integrated device according to an unclaimed embodiment of this application. It can be seen from <FIG> that the first transformer winding <NUM> and the second transformer winding <NUM> may be equivalent to one two-port power converter. In addition, the leakage inductance formed by the first air gap 10a between the first transformer winding <NUM> and the second transformer winding <NUM> may be equivalent to a resonant inductor L0 connected in series to the second transformer winding <NUM>.

In conclusion, the unclaimed embodiments provide a magnetic integrated device. The two transformer windings in the magnetic integrated device may be separated and wound, and the first air gap is formed at separation. The magnetic line may pass through the first air gap to form the leakage inductance, and the leakage inductance may be equivalent to the resonant inductance in the power conversion circuit. Therefore, there is no need to separately dispose the inductor winding in the magnetic integrated device. This effectively reduces the volume and the weight of the magnetic integrated device. In addition, the power conversion circuit that uses the magnetic integrated device also has a relatively small volume and relatively high power density.

Optionally, <FIG> is a schematic structural diagram of another magnetic integrated device according to an embodiment of this application. As shown in <FIG>, the magnetic integrated device may further include a third transformer winding <NUM>. The third transformer winding <NUM> may pass through the window <NUM> and be wound around the magnetic core <NUM>.

Correspondingly, the first transformer winding <NUM>, the second transformer winding <NUM>, and the third transformer winding <NUM> may be equivalent to one three-port power converter.

Optionally, as shown in <FIG>, the third transformer winding <NUM> and the second transformer winding <NUM> may be wound in a laminated manner. To be specific, the third transformer winding <NUM> and the second transformer winding <NUM> may be wound in a same-core manner. A winding manner of winding in the laminated manner can reduce occupied space of the transformer windings. This can effectively reduce the volume of the magnetic integrated device.

<FIG> is an equivalent circuit diagram of a magnetic integrated device when a second transformer winding and a third transformer winding are wound in a laminated manner according to an embodiment of this application. It can be seen from <FIG> that this winding manner can ensure that the third transformer winding <NUM> and the second transformer winding <NUM> are tightly coupled, and there is no leakage inductance between the two transformer windings or there is only relatively small leakage inductance between the two transformer windings. This can effectively reduce power transmission losses between the two transformer windings, and further improve power transmission efficiency between the two transformer windings.

Certainly, the third transformer winding <NUM> may alternatively be separated from and wound around the second transformer winding <NUM> or the first transformer winding <NUM>. For example, the first transformer winding <NUM>, the second transformer winding <NUM>, and the third transformer winding <NUM> may be separated and wound on the magnetic core <NUM> in sequence. A winding position of the third transformer winding <NUM> is not limited in this embodiment of this application.

In this embodiment of this application, one of the first transformer winding <NUM> and the second transformer winding <NUM> may be a winding configured to connect to a direct current bus, and the other winding may be a winding configured to connect to a power battery <NUM> or an auxiliary battery <NUM>.

<FIG> is a schematic structural diagram of still another magnetic integrated device according to an embodiment of this application. It can be seen from <FIG>, <FIG>, and <FIG> that both a quantity of turns of the first transformer winding <NUM> and a quantity of turns of the second transformer winding <NUM> may be greater than a quantity of turns of the third transformer winding <NUM>. To be specific, the third transformer winding <NUM> may be a winding configured to connect to an auxiliary battery <NUM> with a relatively low voltage.

Optionally, the first transformer winding <NUM> may be configured to connect to a power battery <NUM>, and the second transformer winding <NUM> may be configured to connect to the direct current bus. It can be seen from <FIG> that, when the third transformer winding <NUM> and the second transformer winding <NUM> are wound in the laminated manner, the third transformer winding <NUM> (namely, a winding on a side of the auxiliary battery <NUM>) may skip the resonant inductor L0 and be directly coupled to the direct current bus.

A voltage of the direct current bus is relatively stable. Therefore, it can be ensured that a voltage of the winding on the side of the auxiliary battery <NUM> is also relatively stable. This avoids impact of the resonant inductor L0 on a voltage on a low-voltage side, and reduces a voltage fluctuation range on the low-voltage side. In this way, voltage regulation pressure of a post-stage DCDC voltage stabilizing circuit is reduced.

In this embodiment of this application, the third transformer winding <NUM> may be configured to connect to the auxiliary battery <NUM>, and a current in the third transformer winding <NUM> is relatively small. Therefore, as shown in <FIG>, both a wire width of the first transformer winding <NUM> and a wire width of the second transformer winding <NUM> may be less than a wire width of the third transformer winding <NUM>. To be specific, the wire width of the third transformer winding <NUM> may be a relatively large value, and resistance may be a relatively small value. This can effectively reduce a voltage drop of the third transformer winding <NUM>.

For example, still referring to <FIG>, the third transformer winding <NUM> may be flat, to be specific, the third transformer winding <NUM> may be of a bent laminated structure, and the quantity of turns of the third transformer winding <NUM> may be equal to <NUM> or <NUM>. The third transformer winding <NUM> may cover a surface of the second transformer winding <NUM>, to be specific, the third transformer winding <NUM> may be wound on a side that is of the second transformer winding <NUM> and that is away from the magnetic core <NUM>. For example, the flat third transformer winding <NUM> may cover a part of the surface of the second transformer winding <NUM>, and a wiring terminal of the second transformer winding <NUM> may not be covered by the third transformer winding <NUM>, to facilitate connection to an external circuit.

The third transformer winding <NUM> has a relatively small quantity of turns and a relatively large wire width, but the second transformer winding <NUM> has a relatively large quantity of turns and a relatively small wire width. Therefore, the third transformer winding <NUM> is wound on the side that is of the second transformer winding <NUM> and that is away from the magnetic core <NUM>. To be specific, the third transformer winding <NUM> is wound on an outer side of the second transformer winding <NUM>, to facilitate winding of each winding and connection of a post-stage circuit.

As shown in <FIG> and <FIG>, the magnetic core <NUM> includes a first magnet <NUM> and a second magnet <NUM>. A groove or grooves is disposed in one or each of the first magnet <NUM> and the second magnet <NUM>. In other words, the groove is formed in at least one of the two magnets. The first magnet <NUM> and the second magnet <NUM> are disposed opposite to each other and enclose the window <NUM>. In addition, the first magnet <NUM> and the second magnet <NUM> may be bonded and fastened.

For example, it can be seen from <FIG> and <FIG> that one groove may be formed in the second magnet <NUM>, to be specific, the second magnet <NUM> is a U-shaped magnet. No groove is formed in the first magnet <NUM>, and the first magnet <NUM> may be located on a side on which the groove is formed in the second magnet <NUM>, to enclose the window <NUM> with the second magnet <NUM>.

In this embodiment of this application, it can be seen from <FIG> and <FIG> that each transformer winding in the magnetic integrated device may be wound around the first magnet <NUM> and the second magnet <NUM>. For example, referring to <FIG>, the first transformer winding <NUM>, the second transformer winding <NUM>, and the third transformer winding <NUM> included in the magnetic integrated device are respectively wound around the first magnet <NUM> and the second magnet <NUM>. In addition, a part that is of the second transformer winding <NUM> and that is wound around each magnet is covered by the third transformer winding <NUM>.

Optionally, a quantity of turns of each transformer winding in the magnetic integrated device wound around the first magnet <NUM> may be equal to or close to a quantity of turns of each transformer winding wound around the second magnet <NUM>. For example, a difference between the quantities of turns of each transformer winding wound around the two magnets may be less than a turn quantity threshold, and the turn quantity threshold may be <NUM> or <NUM>. This is not limited in this embodiment of this application.

This ensures symmetry of an overall structure of the magnetic integrated device by setting the quantities of turns of each transformer winding wound around the two magnets to be equal or close.

It should be noted that, in this embodiment of this application, the quantity of turns of each transformer winding may be a sum of the quantities of turns of the transformer winding wound around the two magnets.

Optionally, as shown in <FIG>, <FIG>, and <FIG>, the window <NUM> formed in the magnetic core <NUM> may be a rectangular window. To be specific, an orthographic projection shape of the window <NUM> on a plane on which an opening of the window <NUM> is located may be a rectangle. Certainly, the window <NUM> may alternatively be a circular window or another polygon window. A shape of the window is not limited in this embodiment of this application.

It should be further noted that, in this embodiment of this application, the magnetic core <NUM> may alternatively be an integrated part disposed with a through groove. For example, referring to <FIG>, the magnetic core <NUM> may be of a cube structure in which the through groove is disposed. To be specific, the magnetic core <NUM> may be of a "square" shape structure. The through groove is formed as the window <NUM>.

Referring to <FIG> and <FIG>, the magnetic integrated device includes a magnetic pillar <NUM>. The magnetic pillar <NUM> is located in the window <NUM>, and located between the first transformer winding <NUM> and the second transformer winding <NUM>. One side of the magnetic pillar <NUM> comes in contact with the magnetic core <NUM>, and there is a gap between the other side and the magnetic core <NUM>. The gap is the first air gap 10a between the first transformer winding <NUM> and the second transformer winding <NUM>.

As shown in <FIG> and <FIG>, the magnetic pillar <NUM> is located on a side that is of the first magnet <NUM> and that is close to the second magnet <NUM>, and there is a gap between the magnetic pillar <NUM> and the second magnet <NUM>.

Alternatively, the magnetic pillar <NUM> is located on a side that is of the second magnet <NUM> and that is close to the first magnet <NUM>, and there is a gap between the magnetic pillar <NUM> and the first magnet <NUM>.

Alternatively, the magnetic integrated device may include two magnetic pillars <NUM>. One of the magnetic pillars <NUM> is located on a side that is of the first magnet <NUM> and that is close to the second magnet <NUM>, and the other magnetic pillar <NUM> is located on a side that is of the second magnet <NUM> and that is close to the first magnet <NUM>. In addition, there is a gap between the two magnetic pillars <NUM>, to ensure that the first air gap 10a may be formed between the first transformer winding <NUM> and the second transformer winding <NUM>.

For example, the magnetic pillar <NUM> may be of a cube structure. In addition, a volume of the magnetic pillar <NUM> may be adjusted based on a requirement for a value of the resonant inductance in the power conversion circuit to which the magnetic integrated device is applied, to adjust a size of the gap (namely, the first air gap 10a) between the magnetic pillar <NUM> and the magnetic core <NUM>, so as to adjust the leakage inductance of the magnetic integrated device.

For example, when the volume of the magnetic pillar <NUM> is relatively small, and the gap between the magnetic pillar <NUM> and the magnetic core <NUM> is relatively large, the leakage inductance of the magnetic integrated device is relatively large. When the volume of the magnetic pillar <NUM> is relatively large, and the gap between the magnetic pillar <NUM> and the magnetic core <NUM> is relatively small, the leakage sensation of the magnetic integrated device is relatively small.

According to an embodiment of the invention, the magnetic pillar <NUM> and the magnetic core <NUM> may be an integrated structure. In other words, the magnetic pillar <NUM> and the magnetic core <NUM> may be integrally formed. For example, as shown in <FIG> and <FIG>, the magnetic pillar <NUM> and the first magnet <NUM> may be of a T-shaped integrated structure.

In this embodiment of this application, as shown in <FIG> and <FIG>, one or more second air gaps 10b may be further disposed at one end of the magnetic core <NUM>, and the second air gap 10b may be connected to the window <NUM>.

The second air gap 10b may be disposed at the end that is of the magnetic core <NUM> and that is close to the first transformer winding <NUM> or at one end that is of the magnetic core <NUM> and that is close to the second transformer winding <NUM>. Alternatively, the second air gaps 10b may be disposed at both ends of the magnetic core <NUM>.

For example, in the magnetic integrated device shown in <FIG> and <FIG>, one second air gap 10b may be disposed at the end that is of the magnetic core <NUM> and that is close to the first transformer winding <NUM>. The second air gap 10b may be formed by a gap between the first magnet <NUM> and the second magnet <NUM>.

By disposing the second air gap 10b on the magnetic core <NUM>, on one hand, a magnetic permeability of the magnetic core <NUM> can be reduced, and on the other hand, a magnetic saturation phenomenon under a large alternating current signal or a direct current bias can be avoided, to better control inductance of the magnetic integrated device.

In conclusion, the embodiments of this application provide a magnetic integrated device. The two transformer windings in the magnetic integrated device may be separated and wound, and the first air gap is formed at separation. The magnetic line may pass through the first air gap to form the leakage inductance, and the leakage inductance may be equivalent to the resonant inductance in the power conversion circuit. Therefore, there is no need to separately dispose the inductor winding in the magnetic integrated device. This effectively reduces the volume and the weight of the magnetic integrated device. In addition, the power conversion circuit that uses the magnetic integrated device also has the relatively small volume and the relatively high power density, and the power conversion circuit has a relatively good inter-adjustment feature and a relatively high voltage stabilizing capability.

<FIG> is a circuit diagram of a power conversion circuit according to an unclaimed embodiment. As shown in <FIG>, the power conversion circuit may include the magnetic integrated device <NUM> provided in the foregoing embodiments. The magnetic integrated device <NUM> may be the magnetic integrated device shown in <FIG>, <FIG>, or <FIG>. Referring to <FIG>, the power conversion circuit may have at least two ports A and B. In other words, the power conversion circuit may be at least a two-port power conversion circuit. In the magnetic integrated device <NUM>, a first transformer winding <NUM> may be connected to the first port A of the power conversion circuit, and a second transformer winding <NUM> may be connected to the second port B of the power conversion circuit. In addition, the first transformer winding <NUM> and the second transformer winding <NUM> are capable of transferring energy to each other through electromagnetic mutual inductance, and convert power.

Optionally, referring to <FIG>, the power conversion circuit may further include a third port C, and the magnetic integrated device <NUM> may further include a third transformer winding <NUM>. The third transformer winding <NUM> may be connected to the third port C.

In addition, the third transformer winding <NUM> and the first transformer winding <NUM> are capable of transferring energy to each other through electromagnetic mutual inductance, and convert power. The third transformer winding <NUM> and the second transformer winding <NUM> are also capable of transferring energy to each other through electromagnetic mutual inductance, and convert power.

Optionally, as shown in <FIG>, the power conversion circuit may further include three chopper subcircuits <NUM>. Each chopper subcircuit <NUM> may be separately connected to one port and one transformer winding in the magnetic integrated device <NUM>. To be specific, each transformer winding may be connected to one port of the power conversion circuit by using one chopper subcircuit <NUM>.

For example, referring to <FIG>, it is assumed that the first port A of the power conversion circuit is configured to connect to a power battery, the second port B is configured to connect to a direct current bus, and the third port C is configured to connect to an auxiliary battery. In this case, each of the chopper subcircuit <NUM> connected between the first port A and the first transformer winding <NUM> and the chopper subcircuit <NUM> connected between the second port B and the second transformer winding <NUM> may be a bridge rectifier circuit, and the bridge rectifier circuit may include four switch devices connected in a bridge manner. The chopper subcircuit <NUM> connected between the third port C and the third transformer winding <NUM> may be a double half-wave rectifier circuit including two switch devices, or may be a bridge rectifier circuit.

The switch device included in the chopper subcircuit <NUM> may be a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), a gallium nitride (GaN)-based high-electron-mobility transistor (HEMT), or the like, and the MOSFET may be a silicon carbide (SiC) MOSFET or the like.

Optionally, still referring to <FIG>, the power conversion circuit may further include three filter capacitors C0. Each filter capacitor C0 may be connected in parallel to an input terminal of one chopper subcircuit <NUM>.

In this unclaimed embodiment, the power conversion circuit may further include a resonant element, and the resonant element may be connected to the magnetic integrated device <NUM>, to constitute a resonant circuit. To be specific, the power conversion circuit may be a resonant or quasi-resonant power conversion circuit.

In an optional implementation, as shown in <FIG>, the resonant element may include a capacitor C1, and the capacitor C1 may be connected in series to the first transformer winding <NUM> or the second transformer winding <NUM> in the magnetic integrated device <NUM>. For example, in the circuit diagram shown in <FIG>, the capacitor C1 and the second transformer winding <NUM> are connected in series.

A power conversion circuit using this structure may be referred to as an LLC resonant power conversion circuit, or may be referred to as a series-parallel resonant power conversion circuit. L represents an inductor, and C represents a capacitor.

In another optional implementation, as shown in <FIG>, the resonant element may include a first capacitor C2 and a second capacitor C3. The first capacitor C2 may be connected in series to the first transformer winding <NUM> in the magnetic integrated device <NUM>, and the second capacitor C3 may be connected in series to the second transformer winding <NUM> in the magnetic integrated device <NUM>.

A power conversion circuit using this structure may also be referred to as a CLLC resonant power conversion circuit.

In still another optional implementation, as shown in <FIG>, the resonant element may include a capacitor C4 and an inductor L1. The capacitor C4 may be connected in series to the first transformer winding <NUM> or the second transformer winding <NUM> in the magnetic integrated device <NUM>, and the inductor L1 may be connected in parallel to the first transformer winding <NUM> or the second transformer winding <NUM>. For example, in a structure shown in <FIG>, the capacitor C4 is connected in series to the second transformer winding <NUM>, and the inductor L1 is connected in parallel to the second transformer winding <NUM>.

A power conversion circuit using this structure may be referred to as an L-LLC resonant power conversion circuit.

In yet another optional implementation, as shown in <FIG>, no additional resonant element may be disposed in the power conversion circuit, and the leakage inductance in the magnetic integrated device may be equivalent to two resonant inductors L0. The two resonant inductors L0 are respectively connected in series to the first transformer winding <NUM> and the second transformer winding <NUM>. A power conversion circuit using this structure may also be referred to as a dual active full bridge (DAB) power conversion circuit.

In conclusion, the unclaimed embodiments provide a power conversion circuit. In the magnetic integrated device used in the power conversion circuit, the two transformer windings may be separated and wound, and a first air gap is formed at separation. A magnetic line may pass through the first air gap to form leakage inductance, and the leakage inductance may be equivalent to resonant inductance in the power conversion circuit. Therefore, there is no need to separately dispose an inductor winding in the magnetic integrated device. This effectively reduces a volume and a weight of the magnetic integrated device. In addition, the power conversion circuit that uses the magnetic integrated device has a relatively small volume and relatively high power density.

<FIG> is a circuit diagram of still yet power conversion circuit according to an embodiment of this application. As shown in <FIG>, the power conversion circuit has three ports: A, B, and C. In other words, the power conversion circuit is a three-port power conversion circuit. The power conversion circuit may include a resonant element <NUM>, a first transformer T1, and a second transformer T2.

A primary side of the first transformer T1 may be connected in series to the resonant element <NUM> and the first transformer T1 and the resonant element <NUM> that are connected in series may be connected to the second port B of the three ports, and a secondary side of the first transformer T1 may be connected to the first port A of the three ports.

A primary side of the second transformer T2 may be connected in parallel to the first transformer T1 and the resonant element <NUM> that are connected in series. For example, in a structure shown in <FIG>, the resonant element <NUM> may be an inductor L2. In addition, the primary side of the second transformer T2 is further connected to the second port B of the three ports, and a secondary side of the second transformer T2 may be connected to the third port C of the three ports.

The first transformer T1 and the resonant element <NUM> are connected in series, and then connected in parallel to the primary side of the second transformer T2. Therefore, impact of the resonant element <NUM> on an output voltage of the secondary side of the second transformer T2 can be avoided. This ensures that a fluctuation range of the output voltage of the secondary side of the second transformer T2 is relatively small, stability of the output voltage is relatively high, and voltage regulation pressure of a post-stage circuit is further reduced.

It can be learned from the foregoing analysis that in this embodiment of this application, a discrete device may be further used to implement a topology of a power conversion circuit using a magnetic integrated device.

Optionally, the second port B of the power conversion circuit may be configured to connect to a direct current bus, the first port A may be configured to connect to a power battery, and the third port C may be configured to connect to an auxiliary battery.

It should be noted that, in addition to the resonant element <NUM>, the power conversion circuit may further include another resonant element, for example, an inductor and a capacitor, to implement a topology of the power conversion circuit shown in any one of <FIG>. Details are not described in this unclaimed embodiment of this application.

An unclaimed embodiment further provides a charger. As shown in <FIG>, the charger may include the alternating current/direct current conversion circuit <NUM> and the power conversion circuit <NUM>. The power conversion circuit <NUM> may be the circuit shown in any one of <FIG>. A second port B of the power conversion circuit <NUM> may be connected to the alternating current/direct current conversion circuit <NUM>, for example, may be connected to the alternating current/direct current conversion circuit <NUM> by using the direct current bus.

Optionally, the charger may be applied to an electric vehicle, or may be applied to another power driven device, for example, a sweeping robot.

An unclaimed embodiment further provides an electric vehicle. Referring to <FIG>, the electric vehicle may include the power battery <NUM>, the auxiliary battery <NUM>, and the charger <NUM>. The charger <NUM> may be separately connected to the power battery <NUM> and the auxiliary battery <NUM>. For example, a first port A of the power conversion circuit <NUM> included in the charger <NUM> may be connected to the power battery <NUM>, and a third port C of the power conversion circuit <NUM> included in the charger <NUM> may be connected to the auxiliary battery <NUM>.

Optionally, the electric vehicle may be an electric automobile, an electric motorcycle, an electric bicycle, or the like. This is not limited in this unclaimed embodiment.

Claim 1:
A magnetic integrated device, comprising a magnetic core (<NUM>), a first transformer winding (<NUM>), and a second transformer winding (<NUM>), wherein
a window (<NUM>) is disposed in the magnetic core (<NUM>), and the first transformer winding (<NUM>) and the second transformer winding (<NUM>) respectively pass through the window (<NUM>) and are wound around the magnetic core (<NUM>);
wherein the magnetic core (<NUM>) comprises a first piece (<NUM>) and a second piece (<NUM>) disposed opposite to each other and enclosing the window (<NUM>);
the first transformer winding (<NUM>) and the second transformer winding (<NUM>) are separated and each wound around both the first piece (<NUM>) and the second piece (<NUM>),
the first piece (<NUM>) being a I-shaped piece and the second piece (<NUM>) being a U-shape piece comprising a groove in the second piece (<NUM>);
wherein a first part of the first transformer winding (<NUM>) and a first part of the second transformer winding (<NUM>) are both wounded around the second piece (<NUM>) in the groove of the second piece (<NUM>), a second part of the first transformer winding (<NUM>) and a second part of the second transformer winding (<NUM>) are both wounded around the first piece (<NUM>), a first winding axis of the first part of the first transformer winding (<NUM>) and a second winding axis of the first part of the second transformer winding (<NUM>) are aligned, and a third winding axis of the second part of the first transformer winding (<NUM>) and a fourth winding axis of the second part of the second transformer winding (<NUM>) are aligned;
wherein the magnetic integrated device further comprises a magnetic pillar (<NUM>) that is located in the window (<NUM>) and located between the first transformer winding (<NUM>) and the second transformer winding (<NUM>); and
wherein the magnetic pillar (<NUM>) is located on a side of first piece (<NUM>) or on a side of the second piece (<NUM>) and a first side of the magnetic pillar (<NUM>) comes in contact with the magnetic core (<NUM>) on the side on which it is located, and there is a gap between the opposite side to the first side of the magnetic pillar (<NUM>) and the magnetic core (<NUM>).