Patent Application
20160351325
The present invention relates to an inductance coil, and particularly, to a reactor.
Reactor, which is used as reactive power compensation devices, is indispensable in the electric power system. It can be used to limit grid voltage surge and current surge caused by operating over-voltage, smooth spike pulses included in supply voltage, or smooth voltage defects generated during the commutation of bridge rectifier circuit, so as to effectively protect frequency converter and improve the power factor. It can not only prevent interference from the power grid, but also reduce harmonic current generated by rectifier unit to reduce pollution on the grid.
Reactor typically comprises a coil, a coil holder supporting the coil, and a magnetic core surrounded by the coil. The coil is typically made by winding the coil holder with a flexible copper wire. The magnetic core is then enclosed by the coil holder wound by the coil so as to constitute the core part of the reactor.
As electrical equipments are often applied in outdoor environment, the waterproof and dustproof requirements of the reactor are relatively high. The waterproof and dustproof methods that are commonly used by the conventional reactors are wrapping the reactor with an insulating adhesive tape. However, the shape of the combination of the coil, the coil holder and the magnetic core is irregular, and thus, it is difficult to completely attach the insulating adhesive tape on the coil without leaving gaps. Once there exists any gap between the adhesive tape and the coil, the waterproof and dustproof performance will be greatly reduced and thus hard to meet the waterproof and dustproof requirements of the reactor.
In order to further enhance the waterproof and dustproof performance of the reactor, the reactor can be placed in a housing and sealed with resin. However, the housing has a bigger volume, which results in an inductor occupying too much space in the electrical equipments, impairs the ventilation of the electrical equipments, and decreases the heat dissipation performance.
Additionally, the poor thermal conductivity of the sealing resin also impairs the heat dissipation of the coil.
Therefore, the object of the present invention is to overcome the deficiencies of the prior art and provide a reactor.
The present invention provides an inductance coil comprising a magnetic core and a coil, wherein the coil is formed by winding a flat wire, and the flat surface of the wire is perpendicular to the axis around which the coil is wound. The coil is wrapped with an insulating adhesive tape, and the insulating adhesive tape is wound on the wire around an axis which is substantially in line with the direction along which the wire forming the coil extends, so as to form an isolation layer on the surface of the coil.
According to the inductance coil provided in the present invention, the winding direction of the insulating adhesive tape is perpendicular to the winding direction of the coil.
According to the inductance coil provided in the present invention, a gap between the magnetic core and the coil is filled with an insulating material.
According to the inductance coil provided in the present invention, a surface of the inductance coil is coated with a waterproof paint.
According to the inductance coil provided in the present invention, a leading out terminal of the coil is sleeved with a heat-shrinkable tube.
According to the inductance coil provided in the present invention, a leading out terminal of the coil is coated with a sealing gum.
According to the inductance coil provided in the present invention, the magnetic core is an E-I shaped magnetic core, and the coil is located to surround a central column of the E-I shaped magnetic core.
According to the inductance coil provided in the present invention, the magnetic core has an air gap, within which an insulating gasket is provided.
According to the inductance coil provided in the present invention, the inductance coil is a reactor, an inductor, a choke coil or a transformer coil.
The present invention further provides an electromagnetic device comprising the above mentioned inductance coil.
The inductance coil of the present invention does not have a coil holder and thus forms a coil without a coil holder. Therefore, the insulating adhesive tape can be tightly attached to the coil without leaving gaps, and there is no need to add additional waterproof and dustproof parts, for example housing and sealing resin, which will increase the volume of the inductance coil. The waterproof and dustproof performance of the inductance coil of the present invention is improved and its volume is reduced. In addition, the heat dissipation from the coil is not affected.
Below, embodiments of the present invention are further described with reference to the attached drawings, wherein:
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention is further illustrated in detail by the specific embodiments below. It should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.
The present embodiment provides a reactor comprising a magnetic core and a coil.
In this embodiment, the magnetic core of the reactor is an E-I shaped magnetic core.
The coil of the reactor provided in the present embodiment is a vertical wrapping coil, the structure of which is shown in
The reactor provided in the present embodiment uses the coil formed by vertically winding a flat wire. Since the flat wire is wider and has better self-supporting, it is not necessary to provide a coil holder when winding the flat wire and thus a coil without a coil holder can be formed. The shape of the coil is regular, hence, the insulating adhesive tape can be tightly attached to the coil without leaving gaps, such that the waterproof and dustproof performance of the insulating adhesive tape is greatly improved. Accordingly, there is no need to add additional waterproof and dustproof parts, for example housing and sealing resin, which will increase the volume of the inductance coil. Therefore, the volume of the reactor of the present invention is greatly reduced.
In addition, vertically winding is an efficient way for winding. For a certain air gap, a higher inductance value is available in the limited space. For a certain inductive value, the volume occupied by the reactor achieved through vertically winding is smaller than that occupied by other reactors achieved through other winding ways. Therefore, the volume of the reactor is further reduced.
Additionally, in the conventional coil winding way, it is necessary to wind multiple layers of copper wires so as to meet the requirements. However, air gaps with lower thermal conductivity between each layer of the coils are unavoidable, which may cause a high temperature difference between the inside and outside of the coils, even as high as 40° C. Due to this, the internal temperature of the coils may be too high and thus damage the enamel-cover of copper wire and cause interturn short circuit, resulting in the burned inductor. The vertical winding coil of the present embodiment uses a flat wire, the surface of which is perpendicular to the axis around which the coil is wound. Therefore, one layer of the coil can meet requirements. It prevents too high internal temperature and reduces the temperature difference between the inside and outside of the coils.
As described in the embodiment 1, an air gap G with a height h is formed between the central column 21 and the I shaped magnetic core 1. However, leakage flux will cause the central column 21 and the I shaped magnetic core 1 provided on both sides of the air gap G to vibrate and collide, resulting in a noise. The present embodiment provides a reactor which can avoid this noise.
According to other embodiments of the present invention, insulation materials such as epoxy resin can also be filled in the gap between the E-I shaped magnetic core and the coil 3 so as to prevent them from colliding with each other, and prevent turns of the coil colliding with each other due to the effect of electromagnetic force, which may further reduce noises.
According to other embodiments of the present invention, other waterproof and dustproof measures can also be provided to the above reactor so as to further improve its waterproof and dustproof performance. For example, after assembling the coil 3 and the E-I shaped magnetic core, the assembly may be immersed in the Varnish, baked and cooled, and dipped into waterproof paint. It can also improve waterproof and dustproof performance without increasing the volume of the reactor. In addition, a leading out terminal of the coil 3 may be coated with a sealing gum or sleeved with a heat-shrinkable tube to prevent the tape near the leading out terminal not being completely sealed. Using either one of the above waterproof and dustproof measures or any combination of them, the reactor can be completely sealed as a whole such that it is impossible for water to enter any location of the reactor and a high level of waterproof can be achieved.
In the above embodiments, the E-I shaped magnetic core as an example of the reactor according to the present invention has been described. Those skilled in the art will appreciate that the reactor provided in the present invention is not limited to the E-I shaped magnetic core, and other types of magnetic cores may be used based on actual needs.
In essence, the reactor provided in the above embodiments is an inductance coil. The reactor of the above embodiments can also be used in other occasions applying inductance coil, such as inductors, transformers, choke coils, etc. Therefore, the present invention provides an inductance coil, which can be used in any occasion applying inductance coil, for example used as reactors, inductors, chock coils, transformer coils, etc.
Finally, it should be noted that the above embodiments are merely provided for illustrating the technical solutions of the present invention and not for limiting. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art will appreciate that the technical solutions of the invention can be modified or replaced by equivalents, without departing from the spirit and scope of the invention, which are covered by the protection scope of the claims of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410053640.9 | Feb 2014 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2015/072842 | 2/12/2015 | WO | 00 |
