阅读说明：本技术 功率因数校正器 (Power factor corrector ) 是由 罗良敏 朱军 梁定军 胡建 侯俊峰 章文凯 于 2019-11-28 设计创作，主要内容包括：本发明公开了一种功率因数校正器,所述功率因数校正器包括：电感和用于屏蔽所述电感的电磁辐射的屏蔽层；所述电感包括第一区域和第二区域,其中,所述第一区域的辐射强度大于所述第二区域,所述屏蔽层覆盖所述第一区域。由此,通过利用屏蔽层仅覆盖电感的辐射强度较大的区域,从而在有效降低电感向空间辐射干扰,保证电子设备的正常工作的前提下,加强了被屏蔽层屏蔽的电感的散热效果,减小了被屏蔽电感在电路运行过程中的温升,且屏蔽层的成本低,形状简单,大大简化了绝缘处理工艺程序。(The invention discloses a power factor corrector, which comprises: an inductor and a shielding layer for shielding electromagnetic radiation of the inductor; the inductor comprises a first area and a second area, wherein the radiation intensity of the first area is larger than that of the second area, and the shielding layer covers the first area. Therefore, the shielding layer is only used for covering the area with larger radiation intensity of the inductor, so that the radiating effect of the inductor shielded by the shielding layer is enhanced on the premise of effectively reducing the radiation interference of the inductor to the space and ensuring the normal work of the electronic equipment, the temperature rise of the shielded inductor in the circuit operation process is reduced, the cost of the shielding layer is low, the shape is simple, and the insulating treatment process procedure is greatly simplified.)

1. A power factor corrector, comprising:

an inductor and a shielding layer for shielding electromagnetic radiation of the inductor;

the inductor comprises a first area and a second area, wherein the radiation intensity of the first area is larger than that of the second area, and the shielding layer covers the first area.

2. The pfc of claim 1, wherein the inductor is a toroidal inductor formed by winding a conductive wire around a toroidal core, the shielding layer is a shielding ring, the shielding ring is sleeved with an outer ring of the toroidal inductor, a width of an inner space of the shielding ring in the first direction is equal to an outer ring diameter of the toroidal inductor, or a width of the inner space of the shielding ring in the first direction is smaller than the outer ring diameter of the toroidal inductor.

3. The pfc of claim 1, wherein the inductor is a toroidal inductor formed by winding a conductive wire around a toroidal core, and the shielding layer is a shielding ring disposed through an inner ring of the toroidal inductor.

4. The power factor corrector of claim 2 wherein said shield layer has a first opening and a second opening, wherein a radius of said first opening is greater than a radius of said second opening.

5. The power factor corrector of claim 1 wherein said shielding layer comprises a metal layer.

6. The power factor corrector of claim 1 wherein the first region comprises a plurality of sub-regions, the mask layer comprising a plurality of sub-mask layers, the plurality of sub-mask layers covering the plurality of sub-regions.

7. The power factor corrector of any of claims 1 to 6 wherein said shield is provided with openings.

8. The power factor corrector of any of claims 1 to 6 wherein said shield is connected to ground.

9. The power factor corrector of any of claims 1-6, wherein said inductor is any of a common mode inductor, a power factor correction inductor, and a reactor.

Technical Field

The invention relates to the technical field of electronics, in particular to a power factor corrector.

Background

Electromagnetic Interference (EMI) is an electromagnetic disturbance that causes a degradation of the performance of a device, transmission channel or system. The electromagnetic interference comprises two parts of conducted interference and radiated interference, wherein the conducted interference means that interference signals generated by electronic equipment mutually interfere through a conductive medium or a common power line; radiated interference refers to the fact that an electronic device transmits an interfering signal to another electrical network or electronic device through spatial coupling.

Generally, devices such as a switching tube, a diode and an inductor are applied to a high-frequency circuit, the switching tube generates rapid jump of voltage and current when being switched on and off, and reverse recovery current when the diode is switched off has very wide frequency spectrum content, so that higher harmonics are brought, and the higher harmonics and parasitic capacitance of the inductor vibrate to radiate interference to space through the inductor, so that normal work of electronic equipment or other electronic equipment where the inductor is located is influenced. Therefore, how to eliminate the electromagnetic interference of the high-frequency circuit is of great significance to ensure the normal operation of the electronic equipment.

In the related art, generally, a mode of integrally wrapping an inductor with a shielding case is adopted to shield electromagnetic energy radiated outwards by the inductor so as to achieve the purpose of eliminating electromagnetic interference in a high-frequency circuit, however, the mode is not easy to dissipate heat of the inductor, the temperature of the inductor is easily increased too much, the cost of the shielding case is high, in addition, the shape of a shielding layer is complex, and the insulating treatment process is complicated, so that the related art needs to be improved.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the invention provides a power factor corrector, which is used for solving the technical problems that in the related technology, electromagnetic energy radiated outwards by an inductor is shielded in a mode of wrapping the inductor by a shielding cover integrally so as to achieve the purpose of eliminating electromagnetic interference in a high-frequency circuit, the heat dissipation of the inductor is not easy, the temperature rise of the inductor is easy to be overlarge, the cost of the shielding cover is high, the shape of a shielding layer is complex, and the insulating treatment process is complicated.

An embodiment of an aspect of the present invention provides a power factor corrector, including:

an inductor and a shielding layer for shielding electromagnetic radiation of the inductor;

the inductor comprises a first area and a second area, wherein the radiation intensity of the first area is larger than that of the second area, and the shielding layer covers the first area.

According to an embodiment of the present invention, the inductor is a ring inductor formed by winding a wire around a ring-shaped magnetic core, the shielding layer is a shielding ring, the shielding ring is sleeved with an outer ring of the ring inductor, a width of an inner space of the shielding ring in the first direction is equal to a diameter of the outer ring of the ring inductor, or the width of the inner space of the shielding ring in the first direction is smaller than the diameter of the outer ring of the ring inductor.

According to an embodiment of the invention, the inductor is a toroidal inductor formed by winding a conducting wire on a toroidal core, and the shielding layer is a shielding ring, and the shielding ring is arranged in an inner ring of the toroidal inductor in a penetrating manner.

According to one embodiment of the invention, the shielding layer has a first opening and a second opening, wherein a radius of the first opening is larger than a radius of the second opening.

According to an embodiment of the invention, the shielding layer comprises a metal layer.

According to an embodiment of the invention, the first region comprises a plurality of sub-regions, the mask layer comprises a plurality of sub-mask layers, and the plurality of sub-mask layers cover the plurality of sub-regions.

According to one embodiment of the invention, the shielding layer is provided with openings.

According to one embodiment of the invention, the shielding layer is connected to ground.

According to an embodiment of the present invention, the inductor is any one of a common mode inductor, a power factor correction inductor, and a reactor.

The power factor corrector provided by the embodiment of the invention comprises the inductor and the shielding layer for shielding electromagnetic radiation of the inductor, and only the area with higher radiation intensity of the inductor is covered by the shielding layer, so that the heat dissipation effect of the inductor shielded by the shielding layer is enhanced on the premise of effectively reducing the radiation interference of the inductor to the space and ensuring the normal work of electronic equipment, the temperature rise of the shielded inductor in the circuit operation process is reduced, the cost of the shielding layer is low, the shape is simple, and the insulation processing process procedure is greatly simplified.

Drawings

FIG. 1 is a schematic diagram of a partial structure of a power factor corrector according to an embodiment of the present disclosure;

FIG. 2 is another diagram illustrating a partial structure of a power factor corrector according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the disclosure;

FIG. 4 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

FIG. 9 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

FIG. 10 is a schematic diagram of a partial structure of a power factor corrector according to another embodiment of the present disclosure;

fig. 11-14 are graphs illustrating test results of electromagnetic radiation shielding effectiveness for one embodiment of the disclosed invention.

Description of reference numerals:

an inductor-1; a shielding layer-2; a base-3;

a first opening-21; a second opening-22; a first shield ring-23;

a second shield ring-24; opening-4 shield ring height-a;

the width-b of the inner space of the shield ring in the first direction.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

It can be understood that, in a high frequency circuit, a switching tube, a diode, an inductor and other devices are usually applied, a voltage and a current generated when the switching tube is turned on and off jump rapidly, a reverse recovery current generated when the diode is turned off has a very wide frequency spectrum content, so that higher harmonics are brought, and the higher harmonics and a parasitic capacitor of the inductor oscillate, so that the higher harmonics and the parasitic capacitor of the inductor radiate interference to a space through the inductor, thereby affecting the normal operation of an electronic device or other electronic devices where the inductor is located.

Taking a Power Factor Correction (PFC) circuit as an example, a switching Power supply of a computer is a capacitive input circuit, and a phase difference between current and voltage of the circuit causes loss of exchange Power, so that the PFC circuit is required to improve a Power Factor. The power factor correction circuit is divided into an active PFC circuit and a passive PFC circuit. Both the active PFC circuit and the passive PFC circuit employ an inductor, and thus, the PFC circuit may also oscillate due to the higher harmonic and the parasitic capacitance of the inductor, thereby radiating interference to the space through the inductor and affecting the normal operation of the electronic device or other electronic devices where the inductor is located.

In the related art, generally, the mode that the inductor is wrapped by the whole shielding cover is adopted to shield electromagnetic energy radiated outwards by the inductor so as to achieve the purpose of eliminating electromagnetic interference in a high-frequency circuit, however, the mode is not easy to radiate the inductor, the temperature of the inductor is easy to rise too much, the cost of the shielding cover is high, in addition, the shape of the shielding layer is complex, and the insulating treatment process is complicated.

In view of the above problems, embodiments of the present application provide a power factor corrector, where the power factor corrector includes an inductor and a shielding layer for shielding electromagnetic radiation of the inductor, and the inductor includes a first area and a second area, where the radiation intensity of the first area is greater than that of the second area, and the shielding layer covers the first area, so that the shielding layer only covers the area with the greater radiation intensity of the inductor, thereby enhancing the heat dissipation effect of the inductor shielded by the shielding layer, and reducing the temperature rise of the shielded inductor in the circuit operation process, and the shielding layer has a low cost and a simple shape, and greatly simplifies the insulation processing procedures.

The power factor corrector of the embodiments of the present application is described below with reference to the drawings.

Fig. 1 is a schematic diagram of a partial structure of a power factor corrector according to an embodiment of the present disclosure. Fig. 2 is another schematic diagram of a partial structure of a power factor corrector according to an embodiment of the present disclosure. Fig. 1 is a front view, and fig. 2 is a top view corresponding to fig. 1. As shown in fig. 1 and fig. 2, the power factor corrector according to the embodiment of the present application includes:

an inductor 1 and a shielding layer 2 for shielding electromagnetic radiation of the inductor 1;

the inductor 1 comprises a first area and a second area, the radiation intensity of the first area is larger than that of the second area, and the shielding layer 2 covers the first area.

The inductor 1 may be any inductor such as a common mode inductor, a PFC inductor, and a reactor, which is used as an EMI interference source, and the present application does not limit this. In terms of external shape, the inductor 1 may be a toroidal inductor, an E-shaped inductor, a rod inductor, or the like formed by winding a wire around a toroidal core, and fig. 1 and 2 illustrate the inductor 1 as a toroidal inductor as an example.

In some embodiments, the shielding layer 2 may include a metal layer, wherein the metal layer may be made of any metal material capable of shielding electromagnetic radiation of the inductor 1, such as copper foil or any other low-impedance metal material, which is not limited in this application. In addition, the shielding layer 2 may further include other layers such as an insulating layer, which is not limited in this application.

Specifically, the interference radiated outwards by the inductor 1 of the power factor corrector can cause a large eddy current on the shielding layer 2, and due to the demagnetizing effect of the eddy current, the magnetic field at the shielding layer 2 is greatly weakened, so that the interference radiated outwards by the inductor 1 cannot penetrate out of the shielding layer 2, and the interference radiated outwards by the inductor 1 to the space can be inhibited. Similarly, the interference outside the shielding layer 2 cannot penetrate into the shielding layer 2, so that the normal operation of the electronic device and other electronic devices where the power factor corrector is located can be ensured.

In a specific implementation, the power factor corrector provided in the embodiment of the present application may adopt any active power factor correction circuit or passive power factor correction circuit in the prior art, which is not limited in the present application. That is, the present application does not limit the type, number, connection relationship, etc. of the inductor and other components in the pfc. In the application, the shielding layer 2 is only covered on the area with larger radiation intensity of the inductor 1 of the power factor corrector, so that the inductor 1 is locally shielded, the radiation interference of the inductor to the space is effectively reduced, and the normal work of the electronic equipment is ensured.

It can be understood that, when shielding layer 2 carries out whole shielding to inductance 1, shielding layer 2 carries out whole parcel with inductance 1, can form airtight space, the heat that the loss of electric current produced on inductance 1 is difficult to outwards transmit, can cause inductance 1 to generate heat seriously, lead to inductance 1 temperature to rise too big, and shielding layer 2 whole covers inductance 1, the coverage area is big, still can lead to shielding layer 2's cost higher, in addition, shielding layer area is big, the shape is complicated, still can lead to insulating treatment process procedure loaded down with trivial details.

When the inductor 1 radiates interference to the space, the radiation intensity of all the regions is not very large, but the radiation intensity of some regions is large, and the radiation intensity of some regions is small, so in the embodiment of the application, an electromagnetic radiation threshold value may be set, the region where the radiation intensity of the inductor 1 is greater than the electromagnetic radiation threshold value is divided into a first region, and the region where the radiation intensity is not greater than the electromagnetic radiation threshold value is divided into a second region, so that when the inductor 1 is electromagnetically shielded, only the first region where the radiation intensity is greater than the electromagnetic radiation threshold value is covered with a shielding layer, so that while the radiation interference of the inductor 1 to the space is reduced, the area where the inductor 1 directly contacts with the external space is increased, and the heat dissipation effect of the inductor 1 shielded by the shielding layer 2 is enhanced.

Wherein the electromagnetic radiation threshold value can be set according to requirements.

It can be understood that, the smaller the electromagnetic radiation threshold value is set, the larger the area of the first region is, that is, the larger the area that the shielding layer needs to cover is, the better the shielding effect on the inductor 1 is, but the cost of the shielding layer is higher, and the heat dissipation of the inductor is more unfavorable, so, in practical application, the size of the electromagnetic radiation threshold value can be flexibly set according to the requirement on the cost of the shielding layer, the requirement on the shielding effect of the inductor, and the heat dissipation requirement on the inductor, and because the size of the first region is correspondingly changed along with the size of the electromagnetic radiation threshold value, the area of the shielding layer required by the shielding inductor 1 can also be flexibly set.

In the embodiment of the application, the shielding layer 2 is used for locally shielding the first region with high electromagnetic radiation intensity of the inductor 1, on the premise that the shielding performance of the shielding layer 2 on the inductor 1 is not affected, the area of direct contact between the inductor 1 and an external space is increased, the heat dissipation effect of the inductor 1 shielded by the shielding layer 2 is enhanced, the temperature rise of the shielded inductor 1 in the circuit operation process is reduced, the use cost of the shielding layer 2 is greatly reduced compared with that of the inductor 1 when the inductor 1 is completely shielded, the area of the shielding layer 2 is small, the shape is simple, the insulation treatment process is greatly simplified, and the problems of poor heat dissipation effect, high cost and complex process when the inductor 1 is completely shielded are optimized.

Next, the arrangement of the shield layer 2 in the embodiment of the present application will be described by taking an example in which the inductor 1 is a toroidal inductor formed by winding a conductive wire around a toroidal core.

It can be understood that the toroidal inductor is formed by winding a wire around a toroidal core, and since the wire wound around the toroidal core emits electromagnetic energy outwards, and the winding density of the wire around the inner ring of the toroidal core is greater than that of the outer ring, the radiation intensity of the toroidal inductor gradually decreases from the inner ring of the toroidal inductor to the outer ring. In the embodiment of the present application, for the toroidal inductor, the first region having the radiation intensity greater than the electromagnetic radiation threshold is located near the inner ring of the toroidal inductor, and the area of the first region varies according to the set size of the electromagnetic radiation threshold.

In the embodiment of the present application, the shielding layer 2 may be a shielding ring, and the shielding ring can cover an area near an inner ring of the annular inductor 1 to locally shield a strong interference portion of the inductor 1.

In a specific implementation, as shown in fig. 1 and fig. 2, the shielding ring may be sleeved with the outer ring of the annular inductor 1, and the width of the inner space of the shielding ring in the first direction is equal to the diameter of the outer ring of the annular inductor.

The first direction is a direction in which a horizontal symmetry axis of an inner ring or an outer ring of the annular inductor is located, that is, a direction a shown in fig. 1 and 2.

It is understood that, in the embodiment of the present application, as shown in fig. 1, fig. 3, and fig. 4, the inductor 1 of the power factor corrector may be disposed on a base 3 (not shown in fig. 2) (the base 3 is taken as an example for illustration), when the shielding ring is sleeved with the outer ring of the ring inductor, the sleeving direction may be any direction, for example, the transverse plane direction of the shielding ring shown in fig. 1, fig. 3, and fig. 4 is parallel to the plane direction of the base, or the transverse plane direction of the shielding ring may form an angle with the plane direction of the base, and so on. In practical application, in order to facilitate the installation of the shielding layer 2 on the annular inductor 1, the shielding ring may be sleeved on the outer ring of the annular inductor 1 in a manner that the cross-sectional direction of the shielding ring is parallel to the planar direction of the base.

In the embodiment of the present application, the first direction is a direction of a horizontal symmetry axis of an inner ring or an outer ring of the annular inductor, and is defined based on a case where a cross-sectional direction of the shield ring is parallel to a planar direction of the base. That is to say, the first direction is the direction of any symmetry axis of the inner ring or the outer ring of the annular inductor, which direction the first direction is specifically is, and is related to the sleeving direction when the shielding ring is sleeved on the outer ring of the annular inductor, if the shielding ring is sleeved on the outer ring of the annular inductor, the cross section direction of the shielding ring is parallel to the direction of the plane where the base is located, the first direction is the direction of the horizontal symmetry axis of the annular inductor, and if the shielding ring is sleeved on the outer ring of the annular inductor, the cross section direction of the shielding ring is perpendicular to the direction of the plane where the base is located, the first direction is the direction of the vertical symmetry axis of the annular inductor.

In the embodiment of the application, when the shielding ring is sleeved with the outer ring of the annular inductor 1, the width of the inner space of the shielding ring in the first direction is set to be equal to the diameter of the outer ring of the annular inductor, so that the shielding ring can be sleeved in the middle of the annular inductor as shown in fig. 1, and the shielding of the first area with high radiation intensity of the annular inductor is realized.

It should be noted that when the shielding ring is sleeved with the outer ring of the annular inductor 1, the cross section of the shielding ring may be rectangular as shown in fig. 2, or the cross section of the shielding ring may also be elliptical or other shapes. In practical application, the cross-sectional shape of the shielding ring can be flexibly set according to the requirements according to the parameters such as the size of the magnetic core of the toroidal inductor, and the like, which is not limited in the present application.

It should be noted that, when the shielding ring is sleeved with the outer ring of the annular inductor, and the width of the inner space of the shielding ring in the first direction is equal to the diameter of the outer ring of the annular inductor, the height of the shielding ring can be set as required. For example, as shown in fig. 1, the height of the shielding ring may be equal to the diameter of the inner ring of the ring inductor, so that the shielding ring can cover the area near the inner ring of the ring inductor, or, as shown in fig. 3, the height of the shielding ring may be smaller than the diameter of the inner ring of the ring inductor, in which case, the shielding ring only covers a part of the area near the inner ring of the ring inductor.

Compared with the arrangement mode of the shielding ring shown in fig. 1, the arrangement mode shown in fig. 3 can achieve a better heat dissipation effect, and better reduce the temperature rise of the shielded inductor 1 in the circuit operation process, and the use cost of the shielding layer 2 is lower than that of the arrangement mode shown in fig. 1, but the shielding effect is slightly lower than that of the arrangement mode of the shielding ring shown in fig. 1 because the first area is not completely covered. In practical application, the height of the shielding ring can be flexibly set according to requirements so as to meet different requirements. For example, when the requirement on the shielding effect of the inductor is low and the requirement on the heat dissipation effect of the inductor is high, the height of the shielding ring can be set to be smaller than the diameter of the inner ring of the annular inductor, so that the heat dissipation effect is improved.

In some embodiments, as shown in fig. 4, when the shielding ring is sleeved with the outer ring of the annular inductor, the width of the inner space of the shielding ring in the first direction may also be smaller than the diameter of the outer ring of the annular inductor, and at this time, the shielding ring is sleeved on one side of the annular inductor, and the shielding ring only covers a partial area near the inner ring of the annular inductor, so that the shielding effect of the arrangement mode of the shielding ring shown in fig. 3 is slightly worse than that of the arrangement mode of the shielding ring shown in fig. 1.

In some embodiments, when the inductor 1 is a ring inductor, the shielding layer 2 may have a first opening 21 and a second opening 22 as shown in fig. 5, and the shielding layer 2 may be configured as a ring shape with the same width as the upper and lower parts as shown in fig. 1-4, i.e. the radius of the first opening 21 and the radius of the second opening 22 are equal. Alternatively, as shown in fig. 5, the shielding layer 2 may be provided in a horn shape with a narrow top and a wide bottom, that is, the radius of the first opening 21 is larger than that of the second opening 22, so as to facilitate the installation of the shielding layer 2 on the toroidal inductor 1.

In some embodiments, the shielding ring may also be disposed through the inner ring of the toroidal inductor, as shown in fig. 6, that is, the shielding ring penetrates through the inner ring of the toroidal inductor and wraps around a portion of the magnetic core of the toroidal inductor. When the shield ring is inserted into the inner ring of the toroidal inductor, the height of the shield ring (a in fig. 6) and the width of the inner space of the shield ring in the first direction (b in fig. 6) may be adaptively adjusted according to parameters such as the size of the inner ring, the size of the outer ring, and the size of the magnetic core of the toroidal inductor.

In addition, the shielding ring can also be a fan-shaped ring as shown in fig. 7, so that the size of the shielding ring is more matched with that of the annular inductor, and the space occupied by the shielding ring is reduced. The sizes of the radius of the large sector, the radius of the small sector, the inner diameter of the circular tangent plane of the sector ring and the like can be set according to the sizes of the inner ring, the outer ring and the magnetism of the annular inductor.

It should be noted that, when the shielding ring is disposed through the inner ring of the annular inductor, the shielding ring may be disposed at any position of the inner ring, for example, as shown in fig. 6 or 7, the shielding ring is disposed at the left side of the annular inductor, or the shielding ring may be disposed at the upper side, the right side, and the like of the annular inductor, the area of the shielding ring covering the annular inductor may also be adaptively adjusted according to the requirements of the actual application on the heat dissipation and the shielding effect, and the application does not limit the position of the shielding ring and the area of the shielding ring covering the annular inductor.

It is understood that in the embodiment of the present application, a shielding material may be used to cover the region of the inductor 1 where the electromagnetic radiation intensity is high, as described in the above embodiments. In some embodiments, the first region with higher electromagnetic radiation intensity may be further divided into a plurality of sub-regions, and the plurality of sub-regions with higher electromagnetic radiation intensity of the inductor 1 are respectively covered by a plurality of shielding materials. That is, in the embodiment of the present application, when the first region includes a plurality of sub-regions, the shield layer 2 includes a plurality of sub-shield layers, and the plurality of sub-shield layers cover the plurality of sub-regions. Compared with the method that a whole shielding material is used for covering a plurality of areas with higher electromagnetic radiation of the inductor, on the premise that the shielding performance of the shielding layer 2 on the inductor 1 is not influenced, the area of direct contact between the inductor 1 and the external space is further increased, the heat dissipation effect of the inductor 1 shielded by the shielding layer 2 is enhanced, the temperature rise of the shielded inductor 1 in the circuit operation process is reduced, the use cost of the shielding layer 2 is further saved, and the insulation processing process procedure is simplified.

Correspondingly, when the inductor is a ring inductor, the region near the inner ring with high radiation intensity of the ring inductor can be divided into a plurality of sub-regions, and then the plurality of sub-regions are respectively shielded through a plurality of shielding rings.

For example, as shown in fig. 8, two shielding rings, i.e., a first shielding ring 23 and a second shielding ring 24 shown in fig. 8, may be used to cover the region of the toroidal inductor 1 where the electromagnetic radiation intensity is high.

The first shielding ring 23 is sleeved with the upper part of the outer ring of the annular inductor, and the second shielding ring 24 is sleeved with the lower part of the outer ring of the annular inductor. The width of the inner space of the first shielding ring 23 and the second shielding ring 24 in the first direction may be equal to the outer ring diameter of the annular inductor, or smaller than the outer ring diameter of the annular inductor, and the heights of the first shielding ring 23 and the second shielding ring 24 may be set as required. Compared with the method of shielding the annular inductor by using one shielding layer as shown in fig. 1, the shielding method as shown in fig. 8 can achieve a better heat dissipation effect.

It should be noted that, when a plurality of shielding rings are used to shield the annular inductor, the shielding rings may be similar to the manner when one shielding ring is used to shield the annular inductor, and the sleeving direction of the shielding rings is any direction, for example, the cross-sectional direction of the shielding ring shown in fig. 8 is parallel to the plane direction of the base, or the cross-sectional direction of the shielding ring may form a certain included angle with the plane direction of the base, and so on. In practical application, in order to facilitate the installation of the shielding layer 2 on the annular inductor 1, the shielding ring may be sleeved on the outer ring of the annular inductor 1 in a manner that the cross-sectional direction of the shielding ring is parallel to the planar direction of the base.

In addition, when the plurality of shielding rings are respectively sleeved with the outer ring of the annular inductor, the radiuses of the two openings of the plurality of shielding rings may be the same or different, and the application is not limited thereto.

Alternatively, as shown in fig. 9, two shielding rings, i.e., the first shielding ring 23 and the second shielding ring 24 shown in fig. 9, may be used to cover the region of the toroidal inductor 1 where the electromagnetic radiation intensity is high. Wherein, first shield ring 23 and second shield ring 24 all wear to locate annular inductance's inner ring, and first shield ring 23 sets up in annular inductance's left side, and second shield ring 24 sets up on annular inductance's right side. Compared with the method of shielding the annular inductor by using one shielding layer as shown in fig. 6, the shielding method as shown in fig. 9 can achieve a better shielding effect.

When the annular inductor is shielded in a manner that the two shielding rings shown in fig. 9 are inserted into the inner ring of the annular inductor, similar to the shielding manner shown in fig. 6, parameters such as the height of the shielding rings and the width of the inner space of the shielding rings in the first direction may be adaptively adjusted according to parameters such as the sizes of the inner ring, the outer ring, and the magnetic core of the annular inductor. In addition, the shielding rings may be disposed at any position of the annular inductor, for example, as shown in fig. 9, the two shielding rings are disposed on the left side and the right side of the annular inductor, or the two shielding rings may also be disposed on the upper side and the lower side of the annular inductor, and so on, which is not limited in this application.

It should be noted that the manner in which the shielding ring shields the annular inductor shown in the above embodiments of the present application is only an illustrative example, and is not a limitation to the technical solution of the present application, and on the basis of this, a person skilled in the art may arbitrarily set the manner in which the shielding layer shields the inductor as needed, and this is not limited here.

In some embodiments, as shown in fig. 10, the opening 4 may be further disposed on the shielding layer 2, so that on the premise of not affecting the shielding effect of the shielding layer 2 on the inductor 1, the heat dissipation effect of the shielded inductor 1 is further enhanced, and the use cost of the shielding layer 2 is saved.

The shape of the opening may be an ellipse as shown in fig. 10, or may be any other shape, and the position and the number of the opening may also be arbitrarily set according to the need, which is not limited in this application as long as the shape, the position, and the number of the opening do not affect the interference signal of the inductor 1 to form an eddy current on the shielding layer 2.

In some embodiments, the shielding layer 2 may be connected to ground, so that the free charges of the earth neutralize the positive or negative charges on the shielding layer 2, thereby achieving the purpose of electric field shielding.

The electromagnetic radiation shielding effect of the power factor corrector provided in the embodiment of the present application is described below by taking the power factor corrector provided in the air conditioner as an example.

It can be understood that for a power factor corrector in an air conditioner, the emission of conducted interference is mainly radiated interference outward by a PFC inductor, and is coupled to a sensitive wire. If the PFC inductor is not shielded and only a sensitive line is processed, for example, 3 magnetic rings are wound around a power line of an air conditioner and an interconnection line of an internal machine and an external machine, the result of the conducted interference test is shown in fig. 11 and 12.

As can be seen from the test results of fig. 11 and 12, the margin of the conducted interference of the air conditioner is only 3.80 decibels (dB), and at this time, the air conditioner is greatly affected by the interference radiated from the PFC inductor, so that there is a great safety risk, and at this time, when the air conditioner is operating, the inductor temperature is 78 ℃.

If the sensitive wire body is not processed and the shielding layer is adopted to completely shield the inductor, the conduction interference of the air conditioner can be greatly inhibited, but the temperature of the inductor is 115 ℃ when the air conditioner operates. That is, the shielding layer is used to cover the inductor, so that the radiation interference of the inductor to the space can be reduced, but the temperature of the inductor is excessively increased.

On the other hand, if the inductor is partially shielded by the shielding layer, as shown in fig. 1, the inductor is partially covered with a copper foil, and the result of the test of the conducted interference of the air conditioner is shown in fig. 13 and 14.

As can be seen from the test results in fig. 13 and fig. 14, after the method for locally shielding the inductor provided in the embodiment of the present application is adopted, the conducted interference margin of the air conditioner is over 11dB, and when the air conditioner is operated, the temperature of the inductor is 80 ℃, which is not much different from the temperature of the inductor when the sensitive wire is processed. Namely, the shielding layer is adopted to partially cover the inductor, so that the emission amplitude of conducted interference of the air conditioner is greatly reduced, and the problem of overlarge temperature rise of the inductor when the inductor is completely shielded is optimized.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.