Direct current voltage resistance electrical test electric field isolation device for zinc oxide arrester

Abstract

The utility model relates to electrical test technical field, especially relates to a kind of zinc oxide arrester direct current withstand voltage electrical test electric field isolation device, including two half circular annular insulating cylinder, insulating top plate, multiple insulating support cylinder and the dehumidifier for reducing humidity in cylinder;Insulating cylinder is set in arrester outside, and insulating top plate is set in cylinder top, and the upper portion of its is penetrated and is provided with multiple air holes;Insulating support cylinder is set in the side wall of one of insulating cylinder, and the lead of direct current withstand voltage generator is connected through insulating cylinder and arrester;Dehumidifier is set in the side wall position of another insulating cylinder.In the utility model, the closed cylinder that is spliced from two half circular annular insulating cylinder, can effectively shield and isolate the complex ac electric field interference outside arrester, provide a pure electric field environment for direct current withstand voltage test, greatly improve the accuracy and reliability of leakage current measurement value.

Description

Technical Field

[0001] This utility model relates to the field of electrical testing technology, and in particular to an electric field isolation device for DC withstand voltage electrical testing of zinc oxide surge arresters. Background Technology

[0002] Zinc oxide surge arresters with a voltage rating of 110kV and above are installed in transmission lines, primarily for overvoltage protection. The "Power Equipment Maintenance and Testing Regulations" stipulate that zinc oxide surge arresters must undergo a DC withstand voltage and leakage current test after power is de-energized. This test requires checking: ① the critical operating voltage U of the zinc oxide surge arrester at 1mA DC when the ambient humidity is <75%. 1mA ② Zinc oxide surge arresters with ambient humidity < 75% (0.75U) 1mA Leakage current under DC voltage (not greater than 50uA).

[0003] Based on the material characteristics of the MOA (Metal Oxide Asphalt) in zinc oxide surge arresters, the DC withstand voltage test for 110kV-level zinc oxide surge arresters requires a DC voltage of 115kV or higher. This means that the higher the rated voltage of the MOA, the higher the test DC voltage, and the stricter the requirements for the surrounding environment. However, zinc oxide surge arresters are surrounded by numerous high-voltage electrical equipment and metal pipe fittings. The DC electric field generated during the DC withstand voltage boosting process mixes with the surrounding AC electric field, creating a complex electric field phenomenon. Secondly, the testing environment for zinc oxide surge arresters requires humidity <75%. In environments with high humidity, the DC voltage and current fluctuations during the DC withstand voltage electrical test are exacerbated, failing to scientifically and effectively reflect the actual operating conditions of the zinc oxide surge arrester. Some test sites use cranes to remove the zinc oxide surge arrester to the laboratory for electrical testing, which is time-consuming and labor-intensive. These are all common problems currently existing. Effective isolation of the electric field around the zinc oxide surge arrester and removal of humidity from the test environment are essential to maximize the effectiveness and cost-saving of DC withstand voltage testing and to accurately reflect the operating conditions of the zinc oxide surge arrester. Utility Model Content

[0004] In view of the technical problems existing in the background art, the utility model provides an electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester to solve the above-mentioned problems.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows: An electric field isolation device for DC withstand voltage electrical testing of a zinc oxide surge arrester includes two semi-circular annular insulating cylinders, an insulating top plate, multiple insulating support cylinders, and a dehumidifier for reducing humidity inside the cylinders. The two semi-circular annular insulating cylinders can be spliced ​​into an openable and closable cylindrical structure. The insulating cylinders are located outside the surge arrester, and the insulating top plate is located at the top of the cylinder, with multiple ventilation holes extending through its upper part. The insulating support cylinders are located on the side wall of one of the insulating cylinders, and the leads of the DC withstand voltage generator pass through the insulating cylinder and are connected to the surge arrester. The dehumidifier is located on the side wall of the other insulating cylinder.

[0006] Preferably, the device also includes an insulating locking mechanism, which is located at the joint of the two insulating cylinders, and the insulating cylinders are connected by the insulating locking mechanism.

[0007] Preferably, the insulating locking mechanism includes an insulating hinge, an insulating nut, and an insulating screw. The insulating hinge is located on one side of the two insulating cylinders, the insulating screw passes through the insulating hinge and the insulating cylinders, and the insulating nut is located at both ends of the insulating screw.

[0008] Preferably, the insulating cylinder has several connecting holes, the surge arrester has an equalizing ring, and the insulating cylinder and the surge arrester are connected by a rope, which passes through the connecting holes and the equalizing ring.

[0009] Preferably, at least two sets of surge arresters are provided, with the two sets of surge arresters stacked directly. A first base is provided between adjacent surge arresters, and a second base is provided at the lower end of each surge arrester. A grounding wire for the surge arrester is provided on the second base.

[0010] Preferably, several sets of insulating support cylinders are provided, with one set of insulating support cylinders located at the end of the surge arrester, one set of insulating support cylinders located at the first base, and one set of insulating support cylinders located at the second base.

[0011] Preferably, the lower end of the surge arrester is provided with a support base, and the second base is supported on the support base.

[0012] This utility model has the following advantages and beneficial effects: I. Effective Electric Field Isolation: The enclosed cylinder, composed of two semi-circular insulating cylinders, can effectively shield and isolate complex AC electric field interference outside the surge arrester, providing a pure electric field environment for DC withstand voltage testing, and greatly improving the accuracy and reliability of leakage current measurement values.

[0013] II. Precise Humidity Control: The dehumidifier can actively reduce and maintain the humidity inside the cylinder, eliminating the impact of high humidity on the test results and ensuring the compliance and scientific nature of the test conditions.

[0014] III. On-site testing, high efficiency and convenience: The device can be used directly at the installation site of the surge arrester, realizing "on-site testing without disassembling the equipment", saving the huge cost and time of using a crane to disassemble and transport it to the laboratory, and greatly improving the efficiency of the testing work. Attached Figure Description

[0015] Figure 1 This is a structural diagram of an electric field isolation device for DC withstand voltage electrical testing of a zinc oxide surge arrester proposed in this utility model; Figure 2 for Figure 1 A magnified view of a portion of the image; Figure 3 This is a schematic diagram of the internal structure of an electric field isolation device for DC withstand voltage electrical testing of a zinc oxide surge arrester proposed in this utility model; Figure 4 This is a schematic diagram of the structure of the first stage of the surge arrester during the test of the electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester proposed in this utility model; Figure 5 This is a schematic diagram of the second stage of the surge arrester during the test of the electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester proposed in this utility model.

[0016] Reference numerals: 1-Insulating cylinder, 11-Connecting hole, 2-Insulating top plate, 21-Ventilation hole, 3-Insulating support cylinder, 31-First insulating support cylinder, 32-Second insulating support cylinder, 33-Third insulating support cylinder, 4-Dehumidifier, 5-Insulating locking mechanism, 51-Insulating hinge, 52-Insulating screw, 53-Insulating nut, 6-Surge arrester, 61-Equalizing ring, 62-End, 7-First base, 8-Second base, 81-Surge arrester grounding wire, 9-Support base, 91-Support base grounding wire, A-DC withstand voltage generator. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] Example like Figures 1-5As shown, an electric field isolation device for DC withstand voltage electrical testing of zinc oxide surge arrester includes two semi-circular insulating cylinders 1, an insulating top plate 2, multiple insulating support cylinders 3, an insulating locking mechanism 5, and a dehumidifier 4.

[0020] The two insulating cylinders 1 are made of high-strength insulating material (such as FR4 epoxy resin), with smooth and flat inner walls. The two semi-circular insulating cylinders 1 can be spliced ​​together to form an openable and closable cylinder structure. An insulating locking mechanism 5 is set at the joint of the two insulating cylinders 1, and the two insulating cylinders 1 are connected by the insulating locking mechanism 5. The insulating cylinders 1 are set outside the surge arrester 6.

[0021] The insulating locking mechanism 5 includes an insulating hinge 51, an insulating nut 53, and an insulating screw 52. The insulating hinge 51 is made of the same material as the insulating cylinder 1 and is integrally injection molded to ensure consistent insulation performance. The insulating cylinder 1 is provided with mounting holes for installing the insulating locking mechanism 5. The holes on the insulating hinge 51 are aligned with the mounting holes. The insulating screw 52 passes through the insulating hinge 51 and the insulating cylinder 1 at the aligned positions of the two holes and extends into the interior of the insulating cylinder 1. The two ends of the insulating screw 52 are connected to the insulating nuts 53. The insulating hinge 51 connects the two insulating cylinders 1. The insulating screw 52 and the insulating nut 53 connect the insulating hinge 51 and the insulating cylinder 1, thereby forming a detachable and fastened connection between the insulating cylinders 1.

[0022] The insulating top plate 2 is located at the top opening of the insulating cylinder 1 and is fixedly connected to the insulating cylinder 1 by welding or bolting. The insulating top plate 2 is a semi-circular plate structure, and multiple ventilation holes 21 are provided through the insulating top plate 2 to ensure air circulation and prevent external electric field intrusion.

[0023] like Figures 3-5 As shown, at least two sets of surge arresters 6 are provided, arranged in a stacked configuration, one above the other. The upper and lower sets of surge arresters 6 are connected by a first base 7, which is a disc structure made of insulating material. A second base 8, also a disc structure made of insulating material, is located at the lower end of the surge arrester 6. A surge arrester grounding wire 81 is installed on the second base 8. A support seat 9 is located below the second base 8, supporting the entire surge arrester 6. A support seat grounding wire 91 is connected to the side of the support seat 9. An equalizing ring 61 is located at the upper end of the surge arrester 6. The equalizing ring 61 is a ring structure used to evenly distribute high voltage around the object, ensuring no potential difference between different parts of the ring.

[0024] The insulating cylinder 1 has several connecting holes 11 through its wall. The insulating cylinder 1 and the surge arrester 6 are connected by an insulating rope. The insulating rope is made of high-strength insulating fiber. The insulating rope passes through the connecting holes 11, goes around the equalizing ring 61, and then returns to be fixed, increasing the stability of the entire structure.

[0025] A plurality of insulating support cylinders 3 are arranged on the outer side wall of the insulating cylinder 1. The insulating support cylinders 3 adopt a hollow insulating tubular structure, pass through the outer wall of the insulating cylinder 1, and extend into the interior of the insulating cylinder 1. The insulating support cylinders 3 are arranged in three groups along the axial direction of the insulating cylinder 1, including a first insulating support cylinder 31, a second insulating support cylinder 32 and a third insulating support cylinder 33. When the insulating cylinder 1 is hung on the grading ring 61 through an insulating rope member, the first insulating support cylinder 31 is located at the upper part of the insulating cylinder 1, corresponding to the position of the arrester terminal 62; the second insulating support cylinder 32 is located at the middle part of the insulating cylinder 1, corresponding to the position of the first base 7; the third insulating support cylinder 33 is located at the lower end of the insulating cylinder 1, corresponding to the position of the second base 8.

[0026] As Figure 4 shown, when conducting an electrical test on the first-section arrester 6, first place the DC voltage-withstand generator A outside a single insulating cylinder 1. A lead wire is led out from the terminal of the DC voltage-withstand generator A, passes through the first insulating support cylinder 31 and is connected to the terminal 62 of the arrester. The arrester grounding wire 81 passes through the third insulating support cylinder 33 and is connected to the support base grounding wire 91. A lead wire is led out from the first base 7, passes through the second insulating support cylinder 32 and is connected to the support base grounding wire 91. A lead wire is led out from the lower end of the DC voltage-withstand generator A and is connected to the support base grounding wire 91. At this time, the control box matched with the DC voltage-withstand generator A is adjusted to make the voltage rise at a constant speed. During the voltage rising process, pay attention to observing the reading of the microammeter and check the value of the leakage current, so as to realize the electrical test on the first-section arrester 6.

[0027] As Figure 5 shown, when conducting an electrical test on the second-section arrester 6, a lead wire is led out from the terminal of the DC voltage-withstand generator A, passes through the second insulating support cylinder 32 and is connected to the first base 7. The arrester grounding wire 81 passes through the third insulating support cylinder 33 and is connected to the support base grounding wire 91. A lead wire is led out from the lower end of the DC voltage-withstand generator A and is connected to the support base grounding wire 91. At this time, the control box matched with the DC voltage-withstand generator A is adjusted to make the voltage rise at a constant speed. During the voltage rising process, pay attention to observing the reading of the microammeter and check the value of the leakage current, so as to realize the electrical test on the second-section arrester 6.

[0028] The dehumidifier 4 is a PTC heater with a fan of model JRQ-F. Its principle is that the PTC thermistor self-heats and rises in temperature after being electrified, so that its resistance value enters the transition region. The constant-temperature heating PTC thermistor will keep the surface temperature at a constant value, and finally the hot air is blown out through the fan. The dehumidifier 4 is connected to the inside of one of the insulating cylinders 1 by bolts. The control end of the dehumidifier 4 is connected to the outside of the insulating cylinder 1 through a lead wire. When the dehumidifier 4 works, the fan blows hot air to flow inside the insulating cylinder 1 and discharge from the vent hole 21 on the insulating top plate 2. The high-temperature air flow enables the inside of the insulating cylinder 1 to keep dry in a humid environment, reduces the fluctuation of DC voltage and current of the arrester 6, and makes the test data more accurate.

[0029] Working principle: First, place a single insulating cylinder 1 outside the surge arrester 6. The insulating rope passes through the connecting hole 11 and connects to the equalizing ring 61. Then, connect the surge arrester grounding wire 81 through the third insulating support cylinder 33 and connect it to the support base grounding wire 91. Next, connect the lower lead wire of the DC withstand voltage generator A to the support base grounding wire 91. Select different connection positions according to the surge arrester 6 to be measured, so that the surge arrester 6 and the DC withstand voltage generator A are connected. Then, connect another insulating cylinder 1 through the insulating rope and the equalizing ring 61. At this point, the two insulating cylinders 1 are spliced ​​together. The installation position is connected to the insulation locking mechanism 5 to fix the two insulation cylinders 1. The dehumidifier 4 is driven to work through the control terminal of the dehumidifier 4. The fan blows hot air out of the insulation cylinder 1 and the hot air is discharged from the vent 21, so that the inside of the insulation cylinder 1 is kept dry. By controlling the control box of the DC withstand voltage generator A, the voltage is increased, and the value of the microammeter on the control box is observed to check the value of the leakage current to realize the electrical test of the surge arrester 6. After the test is completed, the power supply is disconnected first, then the insulation locking mechanism 5 is opened, and the insulation cylinder 1 component is removed.

[0030] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electric field isolation device for DC withstand voltage electrical testing of zinc oxide surge arresters, characterized in that: It includes two semi-circular insulating cylinders, an insulating top plate, multiple insulating support cylinders, and a dehumidifier for reducing humidity inside the cylinders; the two semi-circular insulating cylinders can be spliced ​​into an openable and closable cylindrical structure; the insulating cylinders are located outside the surge arrester, the insulating top plate is located at the top of the cylindrical structure, and multiple ventilation holes are opened through its upper part; the insulating support cylinders are located on the side wall of one of the insulating cylinders, and the lead wire of the DC withstand voltage generator passes through the insulating cylinder and connects to the surge arrester; the dehumidifier is located on the side wall of the other insulating cylinder.

2. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 1, characterized in that: It also includes an insulating locking mechanism, which is located at the joint of the two insulating cylinders, and the insulating cylinders are connected by the insulating locking mechanism.

3. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 2, characterized in that: The insulating locking mechanism includes an insulating hinge, an insulating nut, and an insulating screw. The insulating hinge is located on one side of the two insulating cylinders, the insulating screw passes through the insulating hinge and the insulating cylinders, and the insulating nut is located at both ends of the insulating screw.

4. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 1, characterized in that: The insulating cylinder has several connecting holes, and the surge arrester is equipped with an equalizing ring. The insulating cylinder and the surge arrester are connected by an insulating rope, which passes through the connecting holes and the equalizing ring.

5. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 1, characterized in that: The surge arrester is provided in at least two sets, and the two sets of surge arresters are stacked directly. A first base is provided between adjacent surge arresters, and a second base is provided at the lower end of the surge arrester. A grounding wire of the surge arrester is provided on the second base.

6. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 5, characterized in that: The insulating support cylinder is provided in several groups, one group of which is located at the end of the surge arrester, one group of which is located at the first base, and one group of which is located at the second base.

7. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 6, characterized in that: The lower end of the surge arrester is provided with a support base, and the second base is supported on the support base.

8. The electric field isolation device for DC withstand voltage electrical test of zinc oxide surge arrester according to claim 7, characterized in that: The second base is provided with a surge arrester grounding wire, and the side of the support base is connected to a support base grounding wire. The surge arrester grounding wire and the support base grounding wire are connected.

Images