An oil-immersed power capacitor with leak-proof design and an alarm method

Abstract

An oil-immersed power capacitor with leak-proof design and an alarm method are disclosed. The outlet bushing of the oil-immersed power capacitor includes a vertical bushing and an angled bushing. The vertical bushing includes a horizontal section and a vertical section. The inlet end of the horizontal section is connected to the power capacitor body, and the inlet end of the vertical section is connected to the outlet end of the horizontal section. The outlet end of the vertical section is connected to the inlet end of the angled bushing, with the outlet end of the angled bushing facing downwards. A displacement sensor is installed at a sealing piston, which transmits the position of the sealing piston to a monitoring system. When the position of the sealing piston reaches a set position threshold, the monitoring system issues an alarm signal. This invention solves the oil leakage problem of power capacitors through structural improvements and also provides a pressure relief channel for insulating oil in case of internal faults in the power capacitor, enabling monitoring of internal faults without damaging the capacitor's seal.

Description

Technical Field

[0001] This invention belongs to the field of power equipment technology, specifically relating to an oil-immersed power capacitor and an alarm method for preventing oil leakage. Background Technology

[0002] Power capacitors, as crucial equipment in power systems, are primarily used in filter construction and reactive power compensation. In 110kV and above substations and DC stations, oil-immersed capacitors are the most common type, where the capacitor is submerged in insulating oil. The main function of the insulating oil is to increase insulation strength and accelerate heat dissipation. In existing projects, the primary arrangement of power capacitors is horizontal, meaning the outgoing lines are in a horizontal direction. The outgoing lines of various existing power capacitor models are mainly located at the ends in this horizontal configuration. However, oil leakage from oil-immersed power capacitors is a frequent occurrence during actual operation.

[0003] Figure 1 This describes the shape of the body and the arrangement of the capacitor bank in existing oil-immersed power capacitor technology. In this type of capacitor, the leads extend horizontally directly from the tank wall, and all the capacitors are placed together on a capacitor rack to form a capacitor bank. During actual operation, oil leakage can occur in oil-immersed power capacitors. There are two possible reasons for this: First, an internal fault may occur. This fault increases internal heat generation, leading to vaporization of the liquid inside the capacitor and the production of small-molecule gases from a small amount of decomposition reaction. This causes a sudden increase in internal liquid pressure. Since the power capacitor is a closed container, it is only sealed at the ends with bolts. The bolts, connected by their interlocking force, have lower strength compared to welding or other methods of connection. Therefore, under the influence of rising oil pressure, the bolts may loosen, causing leakage. Second, insufficient sealing at the leads during assembly can cause the sealing rings to deform or slightly displace under internal oil pressure stress, leading to seal failure and leakage of insulating oil. These two reasons are the main causes of oil leakage in oil-immersed power capacitors.

[0004] During routine maintenance, oil leakage of oil-immersed power capacitors is often found. Once this is discovered, the usual practice is to replace the leaking power capacitor. This will result in a considerable replacement cost and will also increase the workload of inspection.

[0005] Existing technologies have proposed solutions to the oil leakage problem of oil-immersed power capacitors through accident analysis and research on sealing gaskets and sealing methods. However, these studies lack a thorough understanding of the root causes of oil leakage in power capacitors and their potential improvements. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an oil-immersed power capacitor and an alarm method for preventing oil leakage. Starting from the root cause of oil leakage in power capacitors, the invention improves the structure of the power capacitor, solving the problem of oil leakage caused by sealing issues during normal operation. It also provides a pressure relief channel for the insulating oil in case of internal faults in the power capacitor. Furthermore, it enables monitoring of internal faults in the power capacitor without damaging its seal.

[0007] The present invention adopts the following technical solution.

[0008] This invention proposes an oil-immersed power capacitor that is leak-proof and is arranged horizontally. The oil-immersed power capacitor includes: a power capacitor body, a lead sleeve, and lead wires.

[0009] In an oil-immersed power capacitor designed to prevent oil leakage, the outgoing bushing includes a vertical bushing and an angled bushing. The vertical bushing comprises a horizontal section and a vertical section. The inlet end of the horizontal section is connected to the power capacitor body, and the inlet end of the vertical section is connected to the outlet end of the horizontal section. The outlet end of the vertical section is connected to the inlet end of the angled bushing, with the outlet end of the angled bushing oriented diagonally downwards. A sealing piston is provided at the connection between the outlet end of the vertical section and the inlet end of the angled bushing.

[0010] The vertical bushing adopts an L-shaped structure, and the outlet end of the vertical section of the vertical bushing is higher than the height of the power capacitor body; the insulating oil level in the vertical section of the vertical bushing is not lower than the maximum design value of the insulating oil level in the power capacitor body; the maximum design value of the insulating oil level in the power capacitor body is based on the factory parameters of the oil-immersed power capacitor.

[0011] The angled sleeve adopts a ∠-shaped structure, and the included angle between the inlet and outlet ends of the angled sleeve is no greater than 45°.

[0012] The sealing piston slides up and down within the vertical section of the vertical sleeve, and the position of the sealing piston is not lower than the height of the power capacitor body.

[0013] A displacement sensor is installed at the sealing piston, and the displacement sensor sends the position of the sealing piston to the monitoring system; when the position of the sealing piston reaches the set position threshold, the monitoring system issues an alarm signal; the set position threshold is the outlet port of the vertical section of the vertical sleeve.

[0014] The outlet end of the angle bushing is provided with a notch; when an internal fault occurs in the oil-immersed power capacitor, the oil pressure inside the power capacitor increases, causing the insulating oil level in the vertical section of the vertical bushing to rise; when the insulating oil flows into the angle bushing, it flows out from the notch under the action of gravity.

[0015] The lead wires are arranged inside the vertical sleeve and the angled sleeve, and pass through the sealing piston.

[0016] The inlet end of the horizontal section of the vertical bushing is integrally welded to the wall of the power capacitor body.

[0017] Another aspect of the present invention proposes an alarm method for an oil-immersed power capacitor that prevents oil leakage, wherein the alarm method comprises:

[0018] Step 1: Use a displacement sensor to collect the position of the sealing piston and send the position of the sealing piston to the monitoring system;

[0019] Step 2: The monitoring system compares the position of the sealing piston with the set position threshold. If the position of the sealing piston reaches the set position threshold, the monitoring system issues an alarm signal.

[0020] In step 2, the set position threshold is the outlet port of the vertical section of the vertical sleeve.

[0021] The beneficial effects of this invention are compared with those of the prior art:

[0022] 1) This invention modifies the lead-out section of a conventional horizontally arranged capacitor by setting an L-shaped vertical sleeve and a ∠-shaped angled sleeve, so that the final lead-out direction is perpendicular to the capacitor body. This changes the conventional horizontal lead-out method and reduces the oil leakage problem caused by unreliable installation sealing under normal operation by changing the lead-out direction.

[0023] 2) An internally sliding sealing piston is installed at the connection between the vertical bushing and the angle bushing to isolate the battery from the outside air. The sealing piston not only provides a seal but also prevents leakage of insulating oil at the outlet bushing. A displacement sensor is installed at the sealing piston. When the insulating oil leaks due to an internal fault in the power capacitor, the sealing piston moves. When the sealing piston reaches a certain displacement, it sends an alarm signal to the backend. By monitoring the insulating oil level through the sensor, the internal fault monitoring of the power capacitor is achieved. Compared with traditional monitoring methods, this method not only retains the traditional oil spray alarm function but is also more sensitive and reliable.

[0024] 3) The use of L-shaped vertical bushings and ∠-shaped bend bushings forms an insulating oil leakage channel with a certain length. A notch is set at the end of the ∠-shaped bend bushing to provide a pressure relief channel for the capacitor insulating oil and control the leakage direction in case of internal faults, so as to prevent the capacitor from exploding and catching fire under internal fault conditions.

[0025] 4) The product structure proposed in this invention can be fully realized during factory production without increasing the workload of on-site installation and debugging, which is conducive to its promotion and application in engineering.

[0026] 5) The product proposed in this invention can also avoid damaging the flow field distribution, composition and physical properties of the insulating oil inside the power capacitor, and does not affect the original electrical and mechanical properties of the power capacitor. Attached Figure Description

[0027] Figure 1 This refers to the shape of the body of an oil-immersed power capacitor and the arrangement of the capacitor bank in the existing technology;

[0028] Figure 2 This is a schematic diagram of the external shape of an oil-immersed power capacitor that is leak-proof.

[0029] Figure 2 The annotations in the accompanying drawings are explained as follows:

[0030] 1-Power capacitor body; 2-Vertical bushing; 3-Angle bushing; 4-Lead wire; 5-Sealing piston. Detailed Implementation

[0031] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be construed as limiting the scope of protection of the present application.

[0032] like Figure 2 The present invention proposes an oil-immersed power capacitor that is leak-proof and is arranged horizontally. The oil-immersed power capacitor includes: a power capacitor body 1, a lead sleeve, and lead wires 4.

[0033] In an oil-immersed power capacitor designed to prevent oil leakage, the outgoing bushing includes: a vertical bushing 2 and an angled bushing 3. The vertical bushing comprises a horizontal section and a vertical section. The inlet end of the horizontal section is connected to the power capacitor body, and the inlet end of the vertical section is connected to the outlet end of the horizontal section. The outlet end of the vertical section is connected to the inlet end of the angled bushing, and the outlet end of the angled bushing is oriented diagonally downward. A sealing piston 5 is provided at the connection between the outlet end of the vertical section and the inlet end of the angled bushing.

[0034] The vertical bushing adopts an L-shaped structure, and the outlet end of the vertical section of the vertical bushing is higher than the height of the power capacitor body. The insulating oil level in the vertical section of the vertical bushing is not lower than the maximum design value of the insulating oil level in the power capacitor body. The maximum design value of the insulating oil level in the power capacitor body is based on the factory parameters of the oil-immersed power capacitor. This design is to ensure that the inside of the power capacitor body is completely immersed in oil without the insulating oil level dropping.

[0035] The angle bushing adopts a ∠-shaped structure, and the included angle between the inlet and outlet ends of the angle bushing is no greater than 45°. The outlet end of this angle bushing is designed to face downwards at an angle, which avoids the increase of impurities in the insulating oil caused by rain, dust, etc., and avoids clogging the pressure relief channel of the insulating oil.

[0036] The sealing piston slides up and down within the vertical section of the vertical bushing, and its position is not lower than the height of the power capacitor body. The sealing piston also prevents floating impurities from entering the insulating oil.

[0037] A displacement sensor is installed at the sealing piston, and the displacement sensor sends the position of the sealing piston to the monitoring system; when the position of the sealing piston reaches the set position threshold, the monitoring system issues an alarm signal; the set position threshold is the outlet port of the vertical section of the vertical sleeve.

[0038] The outlet end of the angle bushing is provided with a notch; when an internal fault occurs in the oil-immersed power capacitor, the oil pressure inside the power capacitor increases, causing the insulating oil level in the vertical section of the vertical bushing to rise; when the insulating oil flows into the angle bushing, it flows out from the notch under the action of gravity.

[0039] The oil-immersed power capacitor in the preferred embodiment effectively prevents oil leakage caused by poor sealing. Furthermore, its structural design preserves the function of triggering an oil injection alarm in case of internal faults causing oil pressure increases. Even if the internal piston seal malfunctions, oil leakage will not occur under normal operating conditions.

[0040] The lead wires are arranged inside the vertical sleeve and the angled sleeve, and pass through the sealing piston.

[0041] The inlet end of the horizontal section of the vertical bushing is integrally welded to the wall of the power capacitor body.

[0042] Another aspect of the present invention proposes an alarm method for an oil-immersed power capacitor that prevents oil leakage, wherein the alarm method comprises:

[0043] Step 1: Use a displacement sensor to collect the position of the sealing piston and send the position of the sealing piston to the monitoring system;

[0044] Step 2: The monitoring system compares the position of the sealing piston with the set position threshold. If the position of the sealing piston reaches the set position threshold, the monitoring system issues an alarm signal.

[0045] In step 2, the set position threshold is the outlet port of the vertical section of the vertical sleeve.

[0046] The applicant of this invention has provided a detailed description of the embodiments of the invention in conjunction with the accompanying drawings. However, those skilled in the art should understand that the above embodiments are merely preferred embodiments of the invention. The detailed description is only intended to help readers better understand the spirit of the invention and is not intended to limit the scope of protection of the invention. On the contrary, any improvements or modifications made based on the inventive spirit of the invention should fall within the scope of protection of the invention.

Claims

1. A leak-proof oil-immersed power capacitor, arranged horizontally, comprising: The power capacitor body, the outgoing bushing, and the leads are characterized in that, The outlet bushing includes: a vertical bushing and an angled bushing, wherein the vertical bushing includes a horizontal section and a vertical section; the inlet end of the horizontal section of the vertical bushing is connected to the power capacitor body, and the inlet end of the vertical section of the vertical bushing is connected to the outlet end of the horizontal section of the vertical bushing; the outlet end of the vertical section of the vertical bushing is connected to the inlet end of the angled bushing, and the outlet end of the angled bushing is oriented obliquely downward; A sealing piston is installed at the connection between the outlet end of the vertical section of the vertical sleeve and the inlet end of the angled sleeve. The vertical bushing adopts an L-shaped structure, and the outlet end of the vertical section of the vertical bushing is higher than the height of the power capacitor body; the insulating oil level in the vertical section of the vertical bushing is not lower than the maximum design value of the insulating oil level in the power capacitor body; the maximum design value of the insulating oil level in the power capacitor body is based on the factory parameters of the oil-immersed power capacitor.

2. The oil-immersed power capacitor with oil leakage prevention according to claim 1, characterized in that, The angled sleeve adopts a ∠-shaped structure, and the included angle between the inlet and outlet ends of the angled sleeve is no greater than 45°.

3. The oil-immersed power capacitor with oil leakage prevention according to claim 1, characterized in that, The sealing piston slides up and down within the vertical section of the vertical sleeve, and the position of the sealing piston is not lower than the height of the power capacitor body.

4. The oil-immersed power capacitor with oil leakage prevention according to claim 1 or 3, characterized in that, A displacement sensor is installed at the sealing piston, and the displacement sensor sends the position of the sealing piston to the monitoring system; when the position of the sealing piston reaches the set position threshold, the monitoring system issues an alarm signal; the set position threshold is the outlet port of the vertical section of the vertical sleeve.

5. The oil-immersed power capacitor with oil leakage prevention according to claim 2, characterized in that, The outlet end of the angle bushing is provided with a notch; when an internal fault occurs in the oil-immersed power capacitor, the oil pressure inside the power capacitor increases, causing the insulating oil level in the vertical section of the vertical bushing to rise; when the insulating oil flows into the angle bushing, it flows out from the notch under the action of gravity.

6. The oil-immersed power capacitor with oil leakage prevention according to claim 1 or 2, characterized in that, The lead wires are arranged inside the vertical sleeve and the angled sleeve, and pass through the sealing piston.

7. The oil-immersed power capacitor with oil leakage prevention according to claim 1, characterized in that, The inlet end of the horizontal section of the vertical bushing is integrally welded to the wall of the power capacitor body.

8. A method for alarming an oil-immersed power capacitor that prevents oil leakage, using the oil-immersed power capacitor described in any one of claims 1 to 7, characterized in that... The alarm method includes: Step 1: Use a displacement sensor to collect the position of the sealing piston and send the position of the sealing piston to the monitoring system; Step 2: The monitoring system compares the position of the sealing piston with the set position threshold. If the position of the sealing piston reaches the set position threshold, the monitoring system issues an alarm signal.

9. The method for alarming an oil-immersed power capacitor to prevent oil leakage according to claim 8, characterized in that, The set position threshold is the outlet port of the vertical section of the vertical sleeve.

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