WO2019237703A1

WO2019237703A1 - Transformer and electrical device comprising same

Info

Publication number: WO2019237703A1
Application number: PCT/CN2018/122182
Authority: WO
Inventors: 侯俊峰; 胡建; 王贤友
Original assignee: 美的集团股份有限公司
Priority date: 2018-06-14
Filing date: 2018-12-19
Publication date: 2019-12-19
Also published as: CN108831700A

Abstract

The present application relates to a transformer and an electrical device comprising same. The transformer comprises: a primary winding; a secondary winding; an iron core; a mounting base plate; and a shielding layer, said shielding layer being arranged between the primary winding and the secondary winding and being configured to inhibit electromagnetic interference from the secondary winding being coupled to the primary winding, wherein the iron core penetrates the primary winding, secondary winding and shielding layer and is fixed to the mounting base plate.

Description

Transformer and electrical equipment including the same

Cross-reference to related applications

This application is based on a Chinese patent application with an application number of 201810613873.8 and an application date of June 14, 2018, and claims the priority of the Chinese patent application. The entire contents of the Chinese patent application are incorporated herein by reference.

Technical field

This application relates to the field of transformers, but is not limited to the field of transformers, and in particular, to a transformer and electrical equipment including the same.

Background technique

EMC (Electromagnetic Compatibility) is a common problem encountered when designing electrical equipment, that is, electrical equipment needs to work normally in its electromagnetic environment and does not constitute unbearable electromagnetic interference to anything else in the environment.

Power frequency transformer is a common component of electrical equipment, and its structure usually includes primary winding, secondary winding and iron core. The power frequency transformer transforms the power frequency AC input into a subsequent device for use. Figure 1 shows a schematic diagram of the flow of electromagnetic interference noise in an electrical equipment system. As shown in Figure 1, high-frequency electromagnetic interference from the subsequent equipment will flow into the LISN (Line Impedance Stabilization Network) through the distributed capacitance (Cp in Figure 1) of the primary-secondary winding of the power-frequency transformer. And thus detected by LISN.

In view of the above problems, a commonly used EMC design scheme is to add an EMC filter or an EMC filter board at the most port position of the power frequency power input of the electrical equipment (as shown in Figure 1). This solution makes the EMC design scheme complicated and costly due to the additional EMC filtering measures.

Summary of the Invention

The embodiments of the present application provide a transformer including a shielding layer and an electrical device including the same.

According to a first aspect of the present disclosure, there is provided a transformer for electrical equipment, including:

Primary winding

Secondary winding

Iron core

Mounting floor; and

A shielding layer disposed between the primary winding and the secondary winding, configured to suppress electromagnetic interference from the secondary winding from being coupled to the primary winding,

Wherein, the iron core passes through the primary winding, the secondary winding, and the shielding layer and is fixed to the mounting base plate.

According to an exemplary embodiment, the shielding layer is a sheet made of a metal material or a magnetically permeable material, and an insulating layer is provided on both side surfaces.

According to an exemplary embodiment, the shielding layer is any one of the following:

Printed circuit boards whose surfaces are covered with insulating layers on both sides;

A disk made of enameled wire.

According to an exemplary embodiment, the shielding layer has a substantially planar shape, or the shielding layer has a curved shape covering at least one surface of the primary winding or the secondary winding.

According to an exemplary embodiment, a size of the shielding layer is substantially equal to a size of the primary winding or the secondary winding to substantially cover the primary winding or the secondary winding.

According to an exemplary embodiment, the shielding layer has an opening so that the shielding layer cannot form a current loop.

According to an exemplary embodiment, the shielding layer is grounded.

According to an exemplary embodiment, the shielding layer is connected to the iron core.

According to an exemplary embodiment, the iron core fixing includes a first portion having an E-shape and a second portion having a flat plate shape, and the first portion and the second portion are connected together to form a "Japanese" shape to connect all The primary winding, the shielding layer, and the secondary winding are enclosed, wherein a "Japanese" -shaped center pillar passes through the primary winding, the shielding layer, and the secondary winding.

According to an exemplary embodiment, the electrical equipment does not have other EMC devices.

According to an exemplary embodiment, the electrical equipment is any one of the following: a microwave oven, a microwave oven, a high-potential therapeutic apparatus, and a water heater.

According to a second aspect of the present disclosure, there is provided an electric appliance including any one of the embodiments of the transformer as described above.

The technical solutions provided by the embodiments of the present application may include the following beneficial effects:

In the embodiment of the present application, a shielding layer is provided on the primary winding or the secondary winding of the transformer to cut off or suppress the path of electromagnetic interference coupling from the secondary winding to the primary winding, so that electrical equipment does not need an additional EMC filter / EMC filter board It meets the EMC requirements under the circumstance, which simplifies the EMC design scheme and reduces the cost.

It should be understood that the above general description and the following detailed description are merely exemplary, and should not limit the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the description serve to explain the principles of the application.

Figure 1 is a schematic diagram of an EMC design scheme.

FIG. 2 is an overall schematic diagram of a transformer.

FIG. 3 is an exploded schematic diagram of a transformer.

FIG. 4 is an exploded schematic diagram of a transformer according to an exemplary embodiment of the present application.

FIG. 5 is a schematic diagram of assembling completion of the transformer of the exemplary embodiment shown in FIG. 4.

FIG. 6 is an overall schematic diagram of a transformer according to another exemplary embodiment of the present application.

FIG. 7 is a schematic diagram of a shielding layer according to an exemplary embodiment of the present application.

FIG. 8 is a schematic diagram of a shielding layer according to another exemplary embodiment of the present application.

detailed description

In order to further explain the principle and structure of the present application, embodiments of the present application will now be described in detail with reference to the drawings.

FIG. 2 and FIG. 3 respectively show the overall and exploded schematic diagrams of a transformer in the prior art. As shown in FIGS. 2 and 3, a transformer typically includes a primary winding 101, a secondary winding 102, and a core member 103 (such as a core silicon steel sheet). The secondary winding 102 may be a step-up winding or a step-down winding, or may be a multi-winding including both step-up and step-down. The core member 103 passes through the primary winding 101 and the secondary winding 102 and is fixed on the mounting base plate 104. As an embodiment, the core member 103 shown in FIGS. 2 and 3 is composed of a first iron core 1031 having an E shape and a second iron core 1032 having a flat shape to form a “Japanese” shape iron芯件 103。 Core member 103. In the exemplary embodiments shown in FIGS. 2 and 3 and FIGS. 4 to 6, a filament coil 105 is further included between the primary winding 101 and the secondary winding 102, but it can be understood that it is not used for A necessary part of the transformer of the electrical equipment, which can be omitted when used in some electrical equipment. The transformer is installed in electrical equipment and is used to transform the AC input voltage and provide it to the subsequent components in the electrical equipment.

FIG. 4 and FIG. 5 respectively illustrate disassembly and assembly completion diagrams of a transformer according to an exemplary embodiment of the present application. As shown in the embodiments in FIGS. 4 and 5, in addition to the components in FIGS. 2 and 3, the transformer in FIGS. 4 and 5 further includes a shielding layer 106, which is arranged on the primary winding 101 and the secondary side. Between the windings 102, it is configured to provide an electromagnetic shielding effect to suppress the electromagnetic interference from the secondary winding 102 from being coupled to the primary winding 101, thereby at least reducing the electromagnetic interference coupled to the primary winding 101. The core member 103 passes through the primary winding 101, the shielding layer 106, and the secondary winding 102 and is fixed to the mounting base plate 104. In the exemplary embodiment shown in FIGS. 4 to 6, the core member 103 includes a first core 1031 having an E shape and a second core 1032 having a flat plate shape. The first core 1031 and the second core The cores 1032 are connected together to form a "Japanese" shape to enclose the primary winding 101, the shielding layer 106, and the secondary winding 102, and the center pillar 1031A of the "Japanese" shape passes through the primary winding 101, the shielding layer 106 and Secondary side winding 102.

The shielding layer 106 provides electromagnetic shielding for the primary winding 101, and cuts off the high-frequency electromagnetic interference of the subsequent components through the secondary winding 102 through the transformer's equivalent distributed capacitance to the path of the primary winding 101, thereby achieving EMC. It can also be said that the shielding layer 106 provides an electromagnetic shielding effect on the secondary winding 102, that is, shields electromagnetic interference on the secondary winding side, thereby suppressing the coupling of electromagnetic interference to the primary winding side.

In order to ground the shielding layer 106 for better EMC performance, in one exemplary embodiment, the shielding layer 106 is connected to a grounded core member 103. It can be understood that the shielding layer 106 may not be grounded.

In the exemplary embodiments of FIGS. 4 to 5, the shielding layer 106 is shown as being arranged closer to the primary winding 101, and it can be understood that the shielding layer 106 can also be arranged closer to the secondary winding 102, that is, The distance between the shielding layer 10 and the secondary winding 102 is smaller than the distance between the shielding layer 106 and the primary winding 101. The shielding layer 106 may be arranged at any position between the primary winding 101 and the secondary winding 102 as long as it can provide an electromagnetic shielding effect so as to prevent electromagnetic interference from the secondary winding 102 from being coupled to the primary winding 101.

The shielding layer 106 may be a sheet made of a metal material (for example, copper, iron, aluminum, etc.) or a magnetically permeable material (for example, Permalloy). In some embodiments, both sides of the shielding layer 106 have insulating layers. The size of the shielding layer 106 may be designed to be approximately equal to the size of the primary winding 101 or the secondary winding 102 to substantially cover the primary winding 101 or the secondary winding 102. In the exemplary embodiments in FIGS. 4 to 5, the shielding layer 106 is substantially planar and substantially rectangular. It can be understood that the shielding layer 106 may also have a curved surface shape covering at least one surface of the primary winding 101 or the secondary winding 102 (and may also include a part of the side surface of the primary winding 101 or the secondary winding 102). As shown in the exemplary embodiment of FIG. 6, the shielding layer 106 is an open rectangular parallelepiped, and covers one side surface and part of the side surface of the primary winding 101 in a lid shape.

In order to suppress the coupling phenomenon of electromagnetic interference as much as possible, the size of the shielding layer 106 is designed to be equal to the size of the primary winding 101 or the secondary winding 102; or the size of the shielding layer 106 is slightly larger than the primary winding 101 or the secondary winding The size of 102 is such that on the one hand, it can completely cover the primary winding 101 or the secondary winding 102, and on the other hand, it is only slightly larger than the increase in the area or volume of the transformer caused by the shielding layer 106. For example, the size of the shielding layer 106 may be 1.05 or 1.1 times the size of the primary winding 101 or the secondary winding 102.

It can be understood that the structures applicable to the EMC design schemes in the embodiments of the present application are not limited to the transformer structure shown in FIG. 4 to FIG. 6, but may be deformed in many aspects, for example, the primary winding, The shape and size of the secondary winding and the core component, and the positional relationship with the mounting base plate, etc. may be different from those in FIGS. 4 to 6.

7 and 8 show two exemplary embodiments of the shielding layer 106. In the exemplary embodiment of FIG. 7, the shielding layer 106 is a single-layer printed circuit board whose surfaces on both sides are covered with an insulating layer. In the exemplary embodiment of FIG. 8, the shielding layer 106 is a disk made of an enameled wire. The enameled wire may be a metal wire with a surface coated with an insulating varnish or a coating with an insulating varnish or a wire of a magnetically conductive material.

As shown in the exemplary embodiments in FIG. 7 and FIG. 8, in addition to the central hole 1061 through which the core member 103 passes, the shielding layer 106 also has an opening 1062 at the edge, which makes the eddy current in the shielding layer A current loop cannot be formed in 106 to avoid damage to the shielding layer 106 due to heat generation due to eddy currents. Although the shielding layer 106 is shown in a planar shape in FIGS. 7 and 8, it can be understood that they can also be curved shapes. That is, the shielding layer 106 is a shielding layer on which no current loop can be formed.

An embodiment of the present application further provides an electrical device including any one of the embodiments of the transformer as described above. The electrical equipment does not include other EMC devices, for example, does not include additional EMC devices (such as EMC filters / EMC filter boards, etc.) arranged at the port position of the power input.

In one embodiment, the electrical device is a device including a transformer, a magnetron, and a high-voltage rectifier module according to an embodiment of the present application, such as a microwave oven, a microwave oven, and the like.

In another embodiment, the electrical device is a device including a transformer and a high-voltage rectifier module according to an embodiment of the present application, such as a high-potential therapeutic apparatus.

In another embodiment, the electrical device is another device including a transformer according to an embodiment of the present application, such as a water heater.

In summary, the transformer and the electrical equipment including the same according to the embodiments of the present application provide a shielding layer that functions as an electromagnetic shield between the primary winding and the secondary winding, thereby cutting off the coupling of electromagnetic interference between the primary winding and the secondary winding. path. This unique shield design simplifies and reduces EMC design costs.

The above are only exemplary and feasible embodiments of the present application, and do not limit the scope of protection of the present application. Any equivalent structural changes made using the description and drawings of the present application are included in the scope of protection of the present application.

Claims

A transformer for electrical equipment includes:

Primary winding

Secondary winding

Iron core

Mounting floor; and

A shielding layer disposed between the primary winding and the secondary winding and configured to suppress electromagnetic interference from the secondary winding from being coupled to the primary winding,

Wherein, the iron core passes through the primary winding, the secondary winding, and the shielding layer and is fixed to the mounting base plate.
The transformer according to claim 1, wherein the shielding layer comprises: a sheet made of a metal material or a magnetically permeable material, and both sides of the shielding layer have insulating layers.
The transformer according to claim 1, wherein the shielding layer is any one of the following:

Printed circuit boards whose surfaces are covered with insulating layers on both sides;

A disk made of enameled wire.
The transformer according to claim 1, wherein the shielding layer has a substantially planar shape, or the shielding layer has a curved shape covering at least one surface of the primary winding or the secondary winding.
The transformer according to any one of claims 1-4, wherein a size of the shielding layer is substantially equal to a size of the primary winding or the secondary winding to substantially cover the primary winding or the secondary winding Secondary winding.
The transformer according to any one of claims 1-4, wherein the shielding layer has an opening so that the shielding layer cannot form a current loop.
The transformer according to any one of claims 1 to 4, wherein the shield layer is grounded.
The transformer according to claim 7, wherein the shielding layer is connected to the iron core.
The transformer according to any one of claims 1 to 4, wherein the iron core includes a first portion having an E shape and a second portion having a flat plate shape, and the first portion and the second portion are connected to each other. Form a "Japanese" shape together to surround the primary winding, the shielding layer, and the secondary winding, wherein a center pillar of the "Japanese" shape passes through the primary winding, the shielding Layer and the secondary winding.
The transformer according to any one of claims 1 to 4, wherein the electrical equipment does not have other EMC devices.
The transformer according to any one of claims 1 to 4, wherein the electrical equipment is any one of the following: a microwave oven, a microwave oven, a high-potential therapeutic apparatus, and a water heater.
An electrical device comprising the transformer according to any one of claims 1 to 11.