CN206225183U - Transformer grounding resistance device - Google Patents

Abstract

The utility model provides a transformer grounding resistance device, comprising: a transformer (10); a grounding resistance box (20); a flexible cable (30); the first end of the flexible cable (30) is connected with the transformer (10); The second end of the cable (30) is connected to the grounding resistance box (20). The technical solution of the utility model effectively solves the problem of poor flexibility in the connection between the transformer and the grounding resistor in the prior art.

Description

Transformer grounding resistance device

technical field

The utility model relates to the technical field of transformer grounding, in particular to a transformer grounding resistance device.

Background technique

As shown in Figure 1, when a single-phase ground fault occurs in the power system, the grounding transformer 1 makes the power grid form an artificial neutral point for system grounding (such as grounding through the arc-suppression coil), providing a capacitive current that is similar to the grounding capacitive current and has a phase The opposite inductive current compensates the capacitive current to avoid the generation of arc at the grounding point and the harm it causes.

However, some transformers experienced 10kV dry ground transformer faults. In order to explore the effective detection means of the dry-type grounding substation's operating status, the laboratory carried out the grounding substation live detection effectiveness verification test, and used different inspection methods to carry out partial discharge detection experiments on different parts of the dry-type grounding substation, in order to seek best detection method.

As shown in Figure 1, after experimental comparison, it is recommended to use the high-frequency method to detect at the grounding wire of the cable between the neutral point of the grounding transformer and the small resistance box. However, what is used in the prior art is that the neutral point of the grounding transformer 1 (grounding transformer) is connected to the grounding resistance box 2 by connecting the busbar 3, and the existing shape of the busbar 3 is not easy to change during the connection process. Less flexibility.

Utility model content

The main purpose of the utility model is to provide a transformer grounding resistor device to solve the problem of poor flexibility in the connection between the transformer and the grounding resistor in the prior art.

In order to achieve the above object, the utility model provides a transformer grounding resistance device, including: a transformer; a grounding resistance box; a flexible cable, the first end of the flexible cable is connected to the transformer, and the second end of the flexible cable is connected to the grounding resistance box connect.

Further, the flexible cable includes a copper wire, an inner semiconductive layer, an insulating layer, an outer semiconductive layer, copper foil and an outer sheath from the center to the outermost layer, the copper wire is arranged in the center, and the inner semiconductive layer is arranged on the copper wire. Circumferentially outside of the inner semiconductive layer, the insulating layer is arranged on the circumferentially outside of the inner semiconductive layer, the outer semiconductive layer is arranged on the circumferentially outside of the insulating layer, the copper foil is arranged on the circumferentially outside of the outer semiconductive layer, and the outer sheath is arranged on the copper foil the circumferential outer side.

Further, the transformer grounding resistance device further includes a current transformer and a lead wire, the first end of the lead wire communicates with the copper foil, and the second end of the lead wire passes through the current transformer.

Further, the transformer grounding resistance device also includes a box, the box has an accommodation space, and the current transformer is arranged in the box, and the lead wires are inserted into the box from the outside of the box and grounded.

Further, the box has perforations through which the lead wires enter the box.

Further, the box is made of insulating material.

Further, the transformer grounding resistance device also includes a support structure, and the flexible cable is arranged on the support structure.

Further, the bracket structure includes a base and a supporting part, the supporting part is arranged on the base, the supporting part is made of insulating material, the flexible cable is arranged on the supporting part, and the base is arranged on the ground.

Further, the support structure includes a plurality of support structures arranged in the same direction as the axis of the flexible cable.

Further, the copper wire is multi-strand, and the diameter of the copper wire is 40 mm.

Applying the technical scheme of the utility model, the transformer is connected to the grounding resistance box through a flexible cable, because the shape of the flexible cable can be changed, and the length of the flexible cable is easy to realize, which changes the way of connecting the copper bar in the prior art, that is, the transformer and The position between the resistance boxes is not restricted, and the flexible cable can change the track to connect the transformer and the resistance boxes. The technical solution of the utility model effectively solves the problem of poor flexibility in the connection between the transformer and the grounding resistor in the prior art.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. In the attached picture:

Figure 1 shows a schematic diagram of the connection relationship of a transformer grounding resistance device according to the prior art

Fig. 2 shows a schematic diagram of the connection relationship of Embodiment 1 of the transformer grounding resistance device according to the present invention.

Wherein, the above-mentioned accompanying drawings include the following reference signs:

1. Grounding transformer; 2. Grounding resistance box; 3. Busbar; 10. Transformer; 20. Grounding resistance box; 30. Flexible cable.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

For the convenience of description, spatially relative terms may be used here, such as "on ...", "over ...", "on the surface of ...", "above", etc., to describe the The spatial positional relationship between one device or feature shown and other devices or features. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, devices described as "above" or "above" other devices or configurations would then be oriented "beneath" or "above" the other devices or configurations. under other devices or configurations”. Thus, the exemplary term "above" can encompass both an orientation of "above" and "beneath". The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. These example embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It should be understood that these embodiments are provided to make this disclosure of the utility model thorough and complete, and to fully convey the concept of these exemplary embodiments to those of ordinary skill in the art. Thicknesses of layers and regions, and the same reference numerals are used to designate the same devices, and thus their descriptions will be omitted.

As shown in FIG. 2 , the transformer grounding resistance device of Embodiment 1 includes: a transformer 10 , a grounding resistance box 20 and a flexible cable 30 . A first end of the flexible cable 30 is connected to the transformer 10 , and a second end of the flexible cable 30 is connected to the grounding resistance box 20 .

Applying the technical solution of Embodiment 1, the transformer 10 is connected to the grounding resistance box 20 through the flexible cable 30, because the shape of the flexible cable 30 can be changed, and the length of the flexible cable 30 is easy to realize, which changes the prior art that uses copper bars to connect The way, that is, the position between the transformer 10 and the resistance box is not limited, and the flexible cable 30 can change the track to connect the transformer 10 and the resistance box. The technical solution of the first embodiment effectively solves the problem of poor flexibility in connecting the transformer 10 and the grounding resistor in the prior art.

As shown in Figure 2, in the technical solution of Embodiment 1, the flexible cable 30 includes a copper wire, an inner semiconductive layer, an insulating layer, an outer semiconductive layer, a copper foil and an outer sheath from the center to the outermost layer in sequence, and the copper The wire is arranged in the center, the inner semiconductive layer is arranged on the circumferential outer side of the copper wire, the insulating layer is arranged on the circumferential outer side of the inner semiconductive layer, the outer semiconductive layer is arranged on the outer circumferential side of the insulating layer, and the copper foil is arranged on the outer semiconductive layer. The outer sheath is disposed on the outer circumferential side of the copper foil. The flexible cable 30 with the above structure connects the transformer 10 and the grounding resistance box 20 on the one hand, and on the other hand, the internal structure of the flexible cable 30 provides good protection for the passage between the transformer 10 and the grounding resistance box 20 . In addition, the flexible cable 30 having the above-mentioned structure has conditions for further determining failure of the transformer 10 or the ground resistance box 20 .

As shown in Figure 2, in the technical solution of Embodiment 1, the transformer grounding resistance device also includes a current transformer and a lead wire, the first end of the lead wire communicates with the copper foil, and the second end of the lead wire passes through the current transformer and is grounded . The current transformer can detect the voltage change of the lead wire, which is beneficial to find out whether the transformer 10 is faulty. Specifically, the structure of the lead wire is a copper wire in the middle, and an insulating layer on the outer side of the copper wire. When the induced voltage of the current transformer is large, it means that the transformer 10 is faulty. For example, when the absolute value of the signal wave of the current transformer is less than 2V, it indicates that the transformer 10 is relatively normal. When the absolute value of the signal wave of the current transformer is greater than 2V, it indicates that there is a problem with the transformer 10. When a problem occurs, replace the transformer 10. Further specifically, the current transformer has a circular through hole in the middle, and the lead wire passes through the middle circular through hole. Of course, as those skilled in the art know, it is also possible to clamp the current transformer to the lead wire only when measuring the lead wire for measurement.

As shown in FIG. 2 , in the technical solution of Embodiment 1, the transformer grounding resistance device further includes a box, the box has an accommodating space, the current transformer is arranged in the box, and the lead wires are inserted into the box from the outside of the box. The above structure has less influence on the current transformer. Specifically, the box is made of insulating material.

As shown in FIG. 2 , in the technical solution of Embodiment 1, the box has a perforation, and the lead wire enters the box through the perforation. The above-mentioned structure is easy to process and has little influence on the leads.

As shown in FIG. 2 , in the technical solution of Embodiment 1, the transformer grounding resistance device further includes a support structure, and the flexible cable 30 is arranged on the support structure. In this way, the flexible cable 30 has a supporting structure, which on the one hand ensures the safety of the transformer grounding resistance device and prevents problems such as leakage, and on the other hand ensures that the transformer grounding resistance device can be connected in an orderly manner according to a predetermined route.

As shown in Figure 2, in the technical solution of Embodiment 1, the support structure includes a base and a support part, the support part is arranged on the base, the support part is made of insulating material, the flexible cable 30 is arranged on the support part, and the base is arranged on on the ground. The above structure makes the flexible cable 30 contact with the insulating material, which further ensures the safety of electricity use.

As shown in FIG. 2 , in the technical solution of Embodiment 1, the copper wire is multi-strand, and the diameter of the copper wire is 40 mm. The above structure ensures that the connection between the transformer 10 and the grounding resistance box 20 is more effective. Specifically, the thicker diameter of the copper wire will cause waste and cause higher costs, and the thinner diameter of the copper wire will cause the transformer 10 and the grounding resistance box 20 to be more effective. The electrical conductivity between them is poor.

The difference between the transformer grounding resistance device of Embodiment 2 and Embodiment 1 is that the support structure includes multiple rather than a whole. For example, the support structure is composed of multiple hooks, and the hooks are made of insulating materials. Multiple support structures and flexible cables The axis directions of 30 are arranged in the same direction.

The transformer grounding resistance device of the second embodiment includes: a transformer 10 , a grounding resistance box 20 and a flexible cable 30 . A first end of the flexible cable 30 is connected to the transformer 10 , and a second end of the flexible cable 30 is connected to the grounding resistance box 20 .

Applying the technical solution of Embodiment 2, the transformer 10 is connected to the grounding resistance box 20 through the flexible cable 30, because the shape of the flexible cable 30 can be changed, and the length of the flexible cable 30 is easy to realize. The way, that is, the position between the transformer 10 and the resistance box is not limited, and the flexible cable 30 can change the track to connect the transformer 10 and the resistance box. The technical solution of this embodiment effectively solves the problem of poor flexibility in connecting the transformer 10 and the grounding resistor in the prior art.

In the technical solution of Embodiment 2, the flexible cable 30 includes a copper wire, an inner semiconductive layer, an insulating layer, an outer semiconductive layer, copper foil and an outer sheath from the center to the outermost layer, the copper wire is arranged in the center, and the inner The semiconductive layer is arranged on the outer side of the copper wire in the circumferential direction, the insulating layer is arranged on the outer side of the inner semiconductive layer, the outer semiconductive layer is arranged on the outer side of the insulating layer, and the copper foil is arranged on the outer side of the outer semiconductive layer, The outer sheath is provided on the circumferential outer side of the copper foil. The flexible cable 30 with the above structure connects the transformer 10 and the grounding resistance box 20 on the one hand, and on the other hand, the internal structure of the flexible cable 30 provides good protection for the passage between the transformer 10 and the grounding resistance box 20 . In addition, the flexible cable 30 having the above-mentioned structure has conditions for further determining failure of the transformer 10 or the ground resistance box 20 .

In the technical solution of the second embodiment, the transformer grounding resistance device further includes a current transformer and a lead wire, the first end of the lead wire communicates with the copper foil, and the second end of the lead wire passes through the current transformer and is grounded. The current transformer can detect the voltage change of the lead wire, which is beneficial to find out whether the transformer 10 is faulty. Specifically, the structure of the lead wire is a copper wire in the middle, and an insulating layer on the outer side of the copper wire. When the induced voltage of the current transformer is large, it means that the transformer 10 is faulty. For example, when the absolute value of the current transformer is less than 2V, it indicates that the transformer 10 is relatively normal, and when the absolute value of the current transformer is greater than 2V, it indicates that there is a problem with the transformer 10 .

In the technical solution of the second embodiment, the transformer grounding resistance device further includes a box, the box has an accommodation space, the current transformer is arranged in the box, and the lead wires are inserted into the box from the outside of the box. The above structure has less influence on the current transformer. Specifically, the box is made of insulating material.

In the technical solution of the second embodiment, the box has a perforation, and the lead wire enters the box through the perforation. The above-mentioned structure is easy to process and has little influence on the leads.

In the technical solution of the second embodiment, the transformer grounding resistance device further includes a support structure, and the flexible cable 30 is arranged on the support structure. In this way, the flexible cable 30 has a supporting structure, which on the one hand ensures the safety of the transformer grounding resistance device and prevents problems such as leakage, and on the other hand ensures that the transformer grounding resistance device can be connected in an orderly manner according to a predetermined route.

In the technical solution of the second embodiment, the copper wires are multiple strands, and the diameter of the copper wires is 40 mm. The above structure ensures that the connection between the transformer 10 and the grounding resistance box 20 is more effective. Specifically, the thicker diameter of the copper wire will cause waste and cause higher costs, and the thinner diameter of the copper wire will cause the transformer 10 and the grounding resistance box 20 to be more effective. The electrical conductivity between them is poor.

In this application, the high-frequency detection method is used to detect the partial discharge of the grounding transformer. After the high-frequency current sensor is installed in place, the 200pC discharge generated by the grounding transformer can be effectively detected, and the detection will not be affected after the grounding wire is properly extended. Effect. In order to improve the safety and convenience of testing, we have further improved the testing method.

The original busbar is a single-core rigid fixed cable, which is fixed between the neutral point of the grounding transformer and the grounding resistor in an "L" shape, which is not conducive to detection, but it is beneficial to detection after being transformed into a flexible cable for 30 years.

In the busbar connection mode after transformation, we transformed the original single-core rigid fixed busbar into a single-core flexible cable as shown in Figure 2, and grounded the metal shielding layer (copper foil) end of the single-core cable, and the grounding down conductor It can be led to the outside of the grounding transformer fence, and the other end of the metal shielding layer is not grounded. While ensuring the safety of personnel and equipment, the detection process is greatly facilitated.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

It should be noted that the terms "first" and "second" in the specification and claims of the present utility model and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific order or sequence . It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

The above descriptions are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (10)

1. a kind of transformer grounding resistance device, it is characterised in that including：

Transformer (10)；

Earth resistance case (20)；

Flexible cable (30), the first end of the flexible cable (30) is connected with the transformer (10), the flexible cable (30) the second end is connected with the earth resistance case (20).

2. transformer grounding resistance device according to claim 1, it is characterised in that the flexible cable (30) is from center Include copper cash, interior semi-conductive layer, insulating barrier, outer semiconducting layer, Copper Foil and oversheath successively to outermost layer, the copper cash is arranged on Center, the interior semi-conductive layer is arranged on the outer circumferential of the copper cash, and the insulating barrier is arranged on the interior semi-conductive layer Outer circumferential, the outer semiconducting layer is arranged on the outer circumferential of the insulating barrier, and the Copper Foil is arranged on the outer semiconductive The outer circumferential of layer, the oversheath is arranged on the outer circumferential of the Copper Foil.

3. transformer grounding resistance device according to claim 2, it is characterised in that the transformer grounding resistance device Also include current transformer and lead, the first end of the lead is connected with the Copper Foil, and the second end of the lead passes through The current transformer.

4. transformer grounding resistance device according to claim 3, it is characterised in that the transformer grounding resistance device Also include box, the box has receiving space, the current transformer is arranged in the box, the lead is from described Penetrated outside box in the box and be grounded.

5. transformer grounding resistance device according to claim 4, it is characterised in that the box has perforation, described Lead enters in the box through the perforation.

6. transformer grounding resistance device according to claim 4, it is characterised in that the box is by insulating materials system Into.

7. transformer grounding resistance device according to claim 3, it is characterised in that the transformer grounding resistance device Also include supporting structure, the flexible cable (30) is arranged on the supporting structure.

8. transformer grounding resistance device according to claim 7, it is characterised in that the supporting structure include base and Supporting part, the supporting part is arranged on the base, and the supporting part is made up of insulating materials, and the flexible cable (30) sets Put on the supporting part, the base is set on the ground.

9. transformer grounding resistance device according to claim 7, it is characterised in that the supporting structure includes multiple, The axis direction identical set of the multiple supporting structure and the flexible cable (30).

10. transformer grounding resistance device according to claim 2, it is characterised in that the copper cash is multiply, the copper A diameter of 40mm of line.