Relay protection current transformer with protection structure

Abstract

The utility model relates to the technical field of current transformers, in particular to a relay protection current transformer with a protection structure, which comprises an outer shell and a magnetic core, an accommodating box is mounted at the top of the relay protection current transformer, the interior of the accommodating box is communicated with the interior of the outer shell, and an inner shell is further arranged in the outer shell; wherein one magnetic core is fixedly connected with the inner wall of the inner shell, an electromagnet is arranged on the inner wall of the outer shell, and the electromagnet is connected with the movable magnetic core through a spring. An electromagnetic shielding plate is contained in the containing box, and the secondary side winding further winds the electromagnet. The electromagnetic shielding plate has the advantages that the electromagnet is arranged on the secondary side, when current in a circuit is too large abnormally, magnetic force generated by the electromagnet is increased, so that the two closed magnetic cores are separated, the electromagnetic shielding plate falls under the action of gravity and is clamped between the two magnetic cores at the moment that the magnetic cores are separated, and the electromagnetic shielding plate is prevented from falling off. Therefore, the magnetic core is completely separated, the current is cut off, and the protection effect on the secondary side circuit is achieved.

Description

Technical Field

[0001] This utility model relates to the field of power distribution box technology, and more specifically, to a current transformer for relay protection with a protective structure. Background Technology

[0002] Current transformers are based on the principle of electromagnetic induction and achieve voltage transformation through the mutual conversion of electromagnetic fields. They are mainly composed of a closed iron core and coils. In order to perform voltage transformation, there will be a certain difference in the number of turns of the coils on both sides of the iron core. The closed iron core is an essential condition to ensure the circuit inside the current transformer.

[0003] In practical use, current transformers are often used to protect low-current electrical instruments. When a high-voltage current enters the current transformer, it can output a lower voltage and current by utilizing electromagnetic conversion and the different number of coil turns. However, the current transformer itself does not have any circuit breaking structure. The two sets of coils inside do not contact each other; power is transmitted only through electromagnetic fields. Therefore, current transformers usually do not have a circuit breaking structure. In an emergency, the only way to break the circuit is to disconnect the power supply equipment upstream of the current transformer. This option is relatively limited and cannot be applied to the complex installation environments in real life. If the upstream circuit cannot be quickly disconnected in the actual installation environment, the current transformer will not be able to disconnect the circuit and will therefore fail to provide effective circuit breaking protection, thus reducing the practicality of the current transformer. Utility Model Content

[0004] The purpose of this invention is to provide a current transformer for relay protection with a protective structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, a current transformer for relay protection with a protective structure is provided, including a housing, a magnetic core and a base. The housing is mounted on the base, and a receiving box is mounted on its top. The interior of the receiving box is connected to the interior of the housing. An inner shell is also provided inside the housing.

[0006] The magnetic core is composed of two semi-ring magnets of the same size. One of the magnetic cores is fixedly connected to the inner wall of the inner shell. An electromagnet is provided on the inner wall of the outer shell. The electromagnet is connected to the movable magnetic core through a spring.

[0007] The container contains an electromagnetic shielding plate, which can fall into the gap between the two magnetic cores when the two magnetic cores are separated.

[0008] One magnetic core is fixedly connected to the inner shell and wound on the primary side, while the other magnetic core is wound on the secondary side, and the secondary side winding also winds the electromagnet.

[0009] Furthermore, the outer wall of the outer shell is also provided with terminals, the inner shell includes front and rear side plates and a bottom plate, the bottom of the bottom plate is arc-shaped and its top is flat, and the inner wall of the side plates is also provided with guide rails to ensure horizontal displacement of the magnetic core.

[0010] Furthermore, a partition plate is provided on the inner ring side of the two magnetic cores, and the partition plate has a semi-cylindrical structure.

[0011] Furthermore, the spring is specifically a composite rubber spring, and when the two magnetic cores are attached together, the spring is in a stretched state.

[0012] Furthermore, the spring and the electromagnet are vertically fixed to the inner wall of the housing, and the spring and the electromagnet are specifically located on the side close to the movable magnetic core.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] This invention uses an electromagnet on the secondary side. When the current in the circuit is abnormally high, the magnetic force generated by the electromagnet increases, thereby separating the two closed magnetic cores. At the moment of separation, the electromagnetic shielding plate falls under the action of gravity and gets stuck between the two magnetic cores, thus completely separating the magnetic cores and cutting off the current, thereby protecting the secondary circuit. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the magnetic core docking state in an embodiment of this utility model;

[0017] Figure 3 This is a schematic diagram of the magnetic core separation state in an embodiment of this utility model;

[0018] Figure 4 This is a schematic diagram of the inner shell structure in this utility model.

[0019] The meanings of the labels in the diagram are as follows:

[0020] 1. Outer shell; 2. Magnetic core; 3. Base; 4. Receiving box; 5. Inner shell; 501. Side plate; 502. Bottom plate; 6. Electromagnet; 7. Spring; 8. Electromagnetic shielding plate; 9. Terminal block; 10. Divider plate. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0022] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” and “described” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this specification means the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0023] Please see Figure 1-4 As shown, a current transformer for relay protection with a protective structure is provided, including a housing 1, a magnetic core 2 and a base 3. The housing 1 is mounted on the base 3, and a receiving box 4 is mounted on its top. The interior of the receiving box 4 is connected to the interior of the housing 1. An inner shell 5 is also provided inside the housing 1.

[0024] The magnetic core 2 is composed of two semi-annular magnets of the same size. One of the magnetic cores 2 is fixedly connected to the inner wall of the inner shell 5. An electromagnet 6 is provided on the inner wall of the outer shell 1. The electromagnet 6 is connected to the movable magnetic core 2 through a spring 7. The spring 7 and the electromagnet 6 are fixedly connected to the inner wall of the outer shell 1 perpendicularly. The spring 7 and the electromagnet 6 are specifically located on the side close to the movable magnetic core 2.

[0025] The container 4 contains an electromagnetic shielding plate 8. When the two magnetic cores 2 are separated, the electromagnetic shielding plate 8 can fall into the gap between the two magnetic cores 2. In order to ensure that the electromagnetic shielding plate 8 falls accurately into the gap between the two magnetic cores 2, guide grooves or guide tracks can be provided on the inner walls of the container 4 and the inner shell 5.

[0026] The magnetic core 2, which is fixedly connected to the inner shell 5, is wound on the primary side, and the other magnetic core 2 is wound on the secondary side. The secondary side winding also winds the electromagnet 6. It should be noted that when the wire is wound around the electromagnet 6, the number of turns should be greater than the number of turns on the secondary side winding.

[0027] like Figure 3 and Figure 4As shown, in this embodiment, the outer wall of the outer shell 1 is also provided with a terminal post 9. The inner shell 5 includes two side plates 501 at the front and rear and a bottom plate 502 at the bottom. The bottom of the bottom plate 502 is arc-shaped, and its top is flat. The inner wall of the side plate 501 is also provided with a guide rail to ensure the horizontal displacement of the magnetic core 2. The bottom of the bottom plate 502 is arc-shaped so that it can be well fixed inside the outer shell 1, while its top is flat to ensure the normal movement of the magnetic core 2.

[0028] from Figure 3 It can also be seen that in this embodiment, a partition plate 10 is provided on the inner ring side of the two magnetic cores 2. The partition plate 10 has a semi-cylindrical structure. The partition plate 10 can effectively increase the collision area of ​​the two magnetic cores 2 when they dock, prevent the two magnetic cores 2 from being damaged when they dock, and also avoid the weakening of the magnetic force by strong collision.

[0029] Please combine Figure 2 and Figure 3 As shown, the spring 7 is specifically a composite rubber spring. Figure 2 At this time, the electromagnetic shielding plate 8 is inside the housing box 4, and the two magnetic cores 2 on the left and right are attached to each other. In this state, the spring 7 is in a stretched state. However, in this state, the current on the secondary side is normal, and the magnetic force generated on the electromagnet 6 and the tension generated by the spring 7 are insufficient to separate the two magnetic cores 2.

[0030] And in Figure 3 When the current in the secondary side is abnormally large, the magnetic force generated by the electromagnet 6 will increase. At this time, the magnetic force generated by the electromagnet 6 plus the pulling force generated by the spring 7 will separate the two magnetic cores 2. At the moment the magnetic cores 2 separate, the electromagnetic shielding plate 8 falls due to gravity and falls into the space between the two magnetic cores 2. At this time, the two magnetic cores 2 cannot form a closed circuit and cannot generate current in the secondary side.

[0031] Although the electromagnet 6 will lose its magnetic force as a result, the two magnetic cores 2 are separated by the electromagnetic shielding plate 8, thus achieving the protection effect of the secondary side current.

[0032] It should be noted that a reset structure can also be provided in this application to achieve the reset of the electromagnetic shielding plate 8. For this purpose, another embodiment is provided, in which an opening is made in the receiving box 4 and a connecting structure is used to connect it to the electromagnetic shielding plate 8. The electromagnetic shielding plate 8 is reset by controlling the connecting structure. The connecting mechanism here can be a rod, rope or other structure.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A current transformer for relay protection with a protective structure, comprising a housing (1), a magnetic core (2), and a base (3), characterized in that: The outer shell (1) is mounted on the base (3), and a receiving box (4) is mounted on its top. The interior of the receiving box (4) is connected to the interior of the outer shell (1). An inner shell (5) is also provided inside the outer shell (1). The magnetic core (2) is composed of two semi-ring magnets of the same size. One of the magnetic cores (2) is fixedly connected to the inner wall of the inner shell (5). An electromagnet (6) is provided on the inner wall of the outer shell (1). The electromagnet (6) is connected to the movable magnetic core (2) through a spring (7). The container (4) contains an electromagnetic shielding plate (8), which can fall into the gap between the two magnetic cores (2) when the two magnetic cores (2) are separated; The magnetic core (2) fixedly connected to the inner shell (5) is wound on the primary side, and another magnetic core (2) is wound on the secondary side. The secondary side winding also winds the electromagnet (6).

2. A current transformer for relay protection with a protective structure according to claim 1, characterized in that: The outer wall of the outer shell (1) is also provided with a terminal post (9). The inner shell (5) includes two side plates (501) at the front and back and a bottom plate (502) at the bottom. The bottom of the bottom plate (502) is arc-shaped and its top is flat. The inner wall of the side plate (501) is also provided with a guide rail to ensure the horizontal displacement of the magnetic core (2).

3. A current transformer for relay protection with a protective structure according to claim 2, characterized in that: The inner ring sides of the two magnetic cores (2) are provided with partition plates (10), which are semi-cylindrical in shape.

4. A current transformer for relay protection with a protective structure according to claim 2, characterized in that: The spring (7) is specifically a composite rubber spring. When the two magnetic cores (2) are attached together, the spring (7) is in a stretched state.

5. A current transformer for relay protection with a protective structure according to claim 4, characterized in that: The spring (7) and the electromagnet (6) are vertically fixed to the inner wall of the outer shell (1), and the spring (7) and the electromagnet (6) are specifically located on the side close to the movable magnetic core (2).

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