Pressure monitoring and pressure releasing device for clean air insulation current transformer

Abstract

The utility model provides a pressure monitoring and pressure releasing device for a clean air insulation current transformer, which belongs to the field of pressure monitoring and pressure releasing devices and comprises a pressing plate, the edge of the pressing plate is mounted at a gas releasing port of a transformer body through a fastener, and a stepped hole penetrates through the middle of the pressing plate. A release shell is installed below the step face of the stepped hole, a release channel penetrates through the release shell and communicates with the stepped hole and a gas release opening of the mutual inductor body, a control valve is installed in the release channel and electrically connected with a pressure sensor, and the pressure sensor can monitor the pressure of insulating gas in the mutual inductor body. The internal pressure of equipment can be ensured to be within a safe range by releasing insulating gas, and the insulation performance of a product can be prevented from being reduced, so that the safe operation of the product is ensured.

Description

Technical Field

[0001] The utility model belongs to the field of pressure monitoring and pressure relief devices, and particularly relates to a pressure monitoring and pressure relief device for a clean air insulated current transformer. Background Art

[0002] In a high-voltage power system, in order to meet the needs of measurement and relay protection, transformers are usually used, including voltage transformers and current transformers. A current transformer is an electrical instrument that works based on the principle of electromagnetic induction and is mainly used to convert high current (primary side current) into low current (secondary side current) for easy measurement, protection, and control.

[0003] Moreover, during the operation of a current transformer, since the internal insulating gas is prone to pressure increase due to internal faults or overloads, etc., in order to prevent the current transformer from exploding or being damaged and ensure the normal and stable operation of the current transformer and the entire power system, most existing current transformers are equipped with simple pressure relief devices. In this way, when the pressure of the internal insulating gas exceeds the safety threshold that the current transformer can withstand (the rated pressure is 0.4 MPa when sulfur hexafluoride (SF6) gas is used as the insulating medium), the insulating gas inside the current transformer can be released through this pressure relief device.

[0004] However, since the pressure relief device used in traditional current transformers is just a simple bursting disc and does not have a closing function, it will release all the internal insulating gas after the bursting disc explodes, resulting in a rapid decline in the insulation performance of the product and posing a serious threat to the operation of the current transformer. Especially when clean air is used as the insulating gas in the current transformer, since the insulation strength of clean air is lower than that of SF6 gas, it needs to increase the gas pressure to enhance the insulation effect; the gas pressure inside the existing clean air insulated current transformer needs to reach 0.8 MPa (or higher) to meet the insulation requirements, so the traditional pressure relief device cannot meet its usage requirements. Summary of the Utility Model

[0005] The technical problem solved by the utility model is to provide a pressure monitoring and pressure relief device for a clean air insulated current transformer, which can ensure that the internal pressure of the device is within a safe range and avoid the reduction of the insulation performance of the product, thereby ensuring the safe operation of the product.

[0006] To solve the above technical problems, the technical solution provided by the present utility model is as follows: A pressure monitoring and pressure relief device for a clean air-insulated current transformer, comprising a pressing plate. The edge of the pressing plate is installed at the gas release port of the transformer body through fasteners. A stepped hole penetrates through the middle of the pressing plate. A release housing is installed below the step surface of the stepped hole. A release channel penetrates through the release housing. The release channel communicates the stepped hole and the gas release port of the transformer body. A control valve is installed in the release channel. The control valve is electrically connected to a pressure sensor, and the pressure sensor can monitor the pressure of the insulating gas inside the transformer body. In this way, when the pressure of the insulating gas inside the transformer body rises above the safety threshold, the present utility model can monitor the increase in the internal pressure of the transformer body through the pressure sensor and send a corresponding signal to control the opening of the control valve to release some insulating gas until the internal pressure drops to 0.8 MPa, and then close the control valve to avoid the reduction of the insulation performance of the product and ensure the safe operation of the product.

[0007] Further, a bursting disc is installed in the release channel. The bursting disc is arranged inside the control valve. At this time, the present utility model can control the control valve to be in an open state all the time. Under normal pressure conditions, only the bursting disc seals the gas release port of the transformer body. In this way, even if there is a problem with the circuit of the control valve and it cannot be controlled to open, the present utility model can still ensure the smooth release of insulating air through the bursting disc and avoid the explosion of the transformer body.

[0008] Further, a sealing ring is arranged between the release housing and the transformer body, and the sealing between the release housing and the transformer body is achieved through this sealing ring.

[0009] Further, a rain shield is covered outside the pressing plate, and moisture is prevented from entering through this rain shield.

[0010] Further, the fastener is a bolt, and its specific quantity can be flexibly selected according to the size of the pressing plate.

[0011] Further, the bursting disc is an arched grooved bursting disc, which has the characteristics of high operating pressure, wide adaptability, stable state, long service life, etc., and preferably adopts a model with a response time less than 0.001 seconds.

[0012] Further, a filter screen is arranged at the bottom of the release channel, and the bursting disc after bursting is prevented from entering the inside of the transformer body through this filter screen.

[0013] As can be seen from the above technical solutions, the utility model has the following advantages: when the pressure of the insulating gas inside the transformer body rises above the safety threshold, the utility model can monitor the increase in the internal pressure of the transformer body through the pressure sensor and send a corresponding signal to control the control valve to open, releasing some of the insulating gas until the internal pressure drops to 0.8 MPa, and then closing the control valve, effectively controlling the release amount of the insulating gas inside the transformer body to avoid the reduction of the insulation performance of the product and ensure the safe operation of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the present utility model, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 is a schematic structural diagram of the present utility model;

[0016] Figure 2 is a schematic structural diagram of the release housing and the bursting disc in the present utility model (the control valve and the filter screen are not shown).

[0017] In the figure: 1, release housing; 2, sealing ring; 3, rain shield; 4, fastener; 5, pressing plate; 6, transformer body; 7, bursting disc. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0019] Such as Figure 1 、 Figure 2As shown in the figure, the present utility model provides a pressure monitoring and pressure relief device for a clean air-insulated current transformer, which includes a pressing plate 5. A rain shield 3 is provided outside the pressing plate 5. The edge of the pressing plate 5 is installed at the gas release port of the transformer body 6 through fasteners 4 such as bolts. A stepped hole penetrates through the middle of the pressing plate 5. A release housing 1 is installed below the stepped surface of the stepped hole. A sealing ring 2 is provided between the lower end of the release housing 1 and the transformer body 6. A release channel penetrates between the upper and lower ends of the release housing 1. The release channel communicates with the stepped hole and the gas release port of the transformer body 6, and a control valve is installed in the release channel. The control valve is electrically connected to a pressure sensor. The pressure sensor is installed in the cavity of the transformer body 6 so that the pressure sensor can monitor the pressure of the insulating gas inside the transformer body 6, and preferably, the pressure sensor is a high-precision pressure sensor.

[0020] In this way, when the pressure of the insulating gas inside the transformer body 6 rises above the safety threshold, the present utility model can monitor the increase in the internal pressure of the transformer body 6 through the pressure sensor, and send a corresponding signal to control the opening of the control valve to release some insulating gas until the internal pressure drops to 0.8 MPa, and then close the control valve to avoid the reduction of the insulation performance of the product and ensure the safe operation of the product.

[0021] In addition, preferably, the present utility model can also install a rupture disk 7 inside the release channel on the inner side of the control valve. The rupture disk 7 preferably adopts an inverted arch grooved rupture disk. And preferably, a filter screen can be provided below the rupture disk 7 to prevent the ruptured rupture disk 7 from entering the inside of the transformer body 6 through the filter screen. At this time, the present utility model can control the control valve to be in an open state all the time. Under normal pressure conditions, only the rupture disk 7 seals the gas release port of the transformer body. And based on this, even if the circuit of the control valve has problems and cannot be controlled to open, the present utility model can also ensure the smooth release of insulating air through the rupture disk 7, effectively avoiding the explosion of the transformer body 6.

[0022] In addition, it should be noted that the present utility model can be applied not only to clean air-insulated current transformers, but also to current transformers using other insulating gases.

[0023] In the description and claims of the present utility model and the above-mentioned drawings, the terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0024] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A clean air insulated current transformer pressure monitoring and pressure release device, characterized in that: It includes a pressure plate, the edge of which is installed at the gas release port of the transformer body through fasteners, a step hole is passed through the middle of the pressure plate, a release shell is installed below the step surface of the step hole, a release channel is passed through the release shell, the release channel connects the step hole and the gas release port of the transformer body, a control valve is installed in the release channel, the control valve is electrically connected to a pressure sensor, and the pressure sensor can monitor the pressure of the insulating gas inside the transformer body.

2. The clean air insulated current transformer pressure monitoring and pressure release device according to claim 1, characterized in that: A bursting disc is installed in the release channel and is arranged on the inner side of the control valve.

3. The clean air insulated current transformer pressure monitoring and pressure release device according to claim 2, characterized in that: The bursting disc is a reverse-arched grooved bursting disc.

4. The clean air insulated current transformer pressure monitoring and pressure release device according to claim 2, characterized in that: A filter screen is arranged at the bottom of the release channel.

5. The clean air insulated current transformer pressure monitoring and pressure release device according to claim 1, characterized in that: A sealing ring is arranged between the release housing and the transformer body.

6. The clean air insulated current transformer pressure monitoring and pressure release device according to claim 1, characterized in that: The outer side cover of the pressure plate is provided with a rain cover.

7. The clean air insulated current transformer pressure monitoring and pressure release device according to claim 1, characterized in that: The fasteners are bolts.

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