Pressurizing lead connecting device and method for partial discharge test of converter transformer valve side

Abstract

The invention discloses a converter transformer valve side partial discharge test pressurization lead connecting device and method, and the device comprises a conductive part which is made of hard aluminum and has a smooth surface; the universal connecting pieces are mounted at the two ends of the conductive piece; wherein the universal connecting piece located at one end of the conductive piece is used for being connected with a test device; and the universal connecting piece is located at the other end of the guide piece and used for being connected with a converter transformer valve side sleeve. Due to the fact that the conductive part is made of hard aluminum and has high strength, the conductive performance is guaranteed, and meanwhile the convenience of installation with hoisting equipment is improved. The surface of the conductive part is smooth, dust attachment is avoided in the using process, and the problem of suspension discharge interference is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of converter transformer testing, and in particular relates to a converter transformer valve-side partial discharge test pressurized lead connection device and method. Background Art

[0002] With the continuous growth of energy demand, the long transmission distance of electricity and the excessive loss of transmission lines have made DC transmission an inevitable choice for improving the transmission mode. UHV DC transmission has the advantages of large capacity, long distance and low loss, which has a positive effect on improving the safety, stability and economy of the power grid. The converter transformer is one of the core equipment of DC transmission. With the development and application of UHV DC transmission projects, the voltage level is getting higher and higher. The valve side winding excitation voltage of the converter transformer is special and the insulation electric field is complex, which makes it easy to become the weak point of the quality of the UHV converter transformer. When conducting the valve side withstand voltage and partial discharge measurement test of the converter transformer, it is necessary not only to test the withstand voltage strength and insulation performance of the valve side winding to the grid side winding and the ground, but also to control the partial discharge level, which brings great challenges to the test. On the valve side of the converter transformer originally used, during the partial discharge test pressurization process, soft copper wire with suitable cross-sectional area is first used to ensure the current flow, and then a corrugated shielding hose is used externally for uniform electric field. The following technical defects exist in this process: First, since the surface of the corrugated shielding hose is a spiral cylinder, the electrode shape is not very good and a larger diameter tube is required. For example, a 900kV requires a corrugated tube with a diameter of 700 mm; secondly, the corrugated shielding hose is soft and heavy, which is not conducive to installation using equipment such as a crane and is difficult to install; finally, the surface of the corrugated shielding hose is metal aluminum foil, which is extremely easy to damage and can easily cause tip discharge interference, and new corrugated hoses need to be purchased frequently, which is expensive. In addition, the surface of the corrugated shielding hose is a spiral cylinder, which is easy to hide dust and is not easy to clean, which can easily cause suspended discharge interference. Summary of the invention

[0003] The purpose of the present invention is to provide a device and method for connecting pressurized leads for partial discharge test on the valve side of a converter transformer. On the one hand, it is used to solve the technical defects in the prior art that the surface of the corrugated shielding hose used is a metal aluminum foil, which is very easy to be damaged and easily causes tip discharge interference; on the other hand, it is used to solve the technical defects that the surface of the corrugated shielding hose is a spiral cylinder, which is easy to hide dust and is not easy to clean, and easily causes suspended discharge interference. At the same time, the corrugated shielding hose has a large diameter and a soft texture, and is not easy to install.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, a converter transformer valve-side partial discharge test pressurized lead connection device is provided, comprising: The conductive part is made of hard aluminum and has a smooth surface; A universal connector installed at both ends of the conductive member; The universal connector located at one end of the conductive member is used to connect to the test device; the universal connector located at the other end of the guide member is used to connect to the valve-side bushing of the converter transformer.

[0005] Furthermore, the cross section of the conductive member is circular.

[0006] Furthermore, the conductive member is detachably connected to the universal connector.

[0007] Furthermore, the conductive member is a conductive rod.

[0008] In a second aspect, a converter transformer valve side partial discharge test pressurization test method is provided, the method being performed using the connection device as described above, comprising: Install the universal connector at two opposite ends of the conductive part; Binding a sling on the conductive member to connect the conductive member to the lifting device; Adjust the height and angle of the conductive parts, and use universal connectors to connect them to the test pressurizing equipment and the valve-side bushing of the converter transformer.

[0009] Furthermore, before the universal connector is installed at two opposite ends of the conductive member, the method further includes: According to the voltage required for the test, a conductive piece with a corresponding diameter is designed, and a universal connector matching the conductive piece is manufactured.

[0010] Furthermore, the connection with the test pressurizing equipment and the valve-side bushing of the converter transformer specifically includes: One of the universal connectors is electrically connected to the pressurizing device by using fasteners, and the other universal connector is connected to the valve-side bushing of the converter transformer.

[0011] Furthermore, it also includes: Clean the surface of the conductive parts to prevent discharge interference at the tip of the conductive parts during pressurization.

[0012] Furthermore, the surface of the conductive member is cleaned, specifically: Use alcohol to clean the conductive parts to ensure that the surface of the conductive parts is free of impurities and smooth.

[0013] Furthermore, the binding sling is specifically: Place the conductive part on the mobile bracket and tie the slings at the appropriate positions on both ends of the conductive part.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Since the conductive parts are made of hard aluminum, they have high strength, which ensures the conductive performance while improving the convenience of installation with lifting equipment; the surface of the conductive parts is smooth, which avoids dust adhesion during use and solves the problem of suspended discharge interference.

[0015] 2. The cross section of the conductive part is designed to be circular, which ensures the reliability of the connection in terms of connection length.

[0016] 3. The detachable connection allows the conductive parts and the universal connector to be easily separated and reassembled, which greatly enhances the flexibility of the device. At the test site, different specifications or damaged parts can be quickly replaced according to actual needs without replacing the entire connection device, thereby improving maintenance efficiency and test continuity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of a pressure lead connection device for a converter transformer valve-side partial discharge test proposed by the present invention; Figure 2 This is a flow chart of the pressure test method for the converter transformer valve side partial discharge test proposed by the present invention; Among them: 1. Conductive parts; 2. Universal connecting parts. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] 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 invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0023] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] With the continuous growth of energy demand, the long transmission distance of electricity and the excessive loss of transmission lines have made DC transmission an inevitable choice for improving the transmission mode. UHV DC transmission has the advantages of large capacity, long distance and low loss, which has a positive effect on improving the safety, stability and economy of the power grid. The converter transformer is one of the core equipment of DC transmission. With the development and application of UHV DC transmission projects, the voltage level is getting higher and higher. The valve side winding excitation voltage of the converter transformer is special and the insulation electric field is complex, which makes it easy to become the weak point of the quality of the UHV converter transformer. When conducting the valve side withstand voltage and partial discharge measurement test of the converter transformer, it is necessary not only to test the withstand voltage strength and insulation performance of the valve side winding to the grid side winding and the ground, but also to control the partial discharge level, which brings great challenges to the test. On the valve side of the converter transformer originally used, during the partial discharge test pressurization process, soft copper wire with suitable cross-sectional area is first used to ensure the current flow, and then a corrugated shielding hose is used externally for uniform electric field. The following technical defects exist in this process: First, since the surface of the corrugated shielding hose is a spiral cylinder, the electrode shape is not very good and a larger diameter tube is required. For example, a 900kV requires a corrugated tube with a diameter of 700 mm; secondly, the corrugated shielding hose is soft and heavy, which is not conducive to installation using equipment such as a crane and is difficult to install; finally, the surface of the corrugated shielding hose is metal aluminum foil, which is extremely easy to damage and can easily cause tip discharge interference, and new corrugated hoses need to be purchased frequently, which is expensive. In addition, the surface of the corrugated shielding hose is a spiral cylinder, which is easy to hide dust and is not easy to clean, which can easily cause suspended discharge interference.

[0025] In order to solve the above technical defects, the inventor provides a converter transformer valve-side partial discharge test pressurized lead connection device and method.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1 As shown, the embodiment of the present invention, in the first aspect, provides a converter transformer valve side partial discharge test pressurized lead connection device, comprising: a conductive part 1, made of hard aluminum and having a smooth surface; a universal connector 2, installed at both ends of the conductive part 1; wherein the universal connector 2 located at one end of the conductive part 1 is used to connect with the test device, and the universal connector 2 located at the other end of the guide part 1 is used to connect with the converter transformer valve side bushing. In this process, since the conductive part 1 is made of hard aluminum, it has a higher strength, while ensuring the conductive performance, it improves the convenience of installation with the lifting equipment, and there is no need to worry about the problem of damage to the conductive part 1; secondly, since the surface of the conductive part 1 is smooth, dust adhesion is avoided during the subsequent pressurization test, solving the problem of suspended discharge interference. In addition, the conductive part 1 is made of hard aluminum. Aluminum is a good conductor with excellent conductivity, which can ensure the stable transmission of current in the partial discharge test and reduce energy loss and signal attenuation. The universal connectors 2 installed at both ends of the conductive part 1 enable the conductive part 1 to flexibly adapt to the connection requirements of different angles and positions. Whether it is connected to the test device or the valve-side bushing of the converter transformer, it can achieve fast and accurate docking, further improving the efficiency and convenience of the test. The smooth surface design of the conductive part 1 reduces the resistance and heat generation during the current transmission process, and reduces the safety hazards caused by overheating. At the same time, the hard aluminum material itself also has good mechanical strength and corrosion resistance, which can ensure the stability and safety of the connection device during long-term use. Figure 1As shown, the cross section of the conductive member 1 is circular, and the conductive member 1 is detachably connected to the universal connector 2. The conductive member 1 with a circular cross section can provide a larger current-carrying area, which helps the current to be transmitted more stably and evenly in the conductive member 1, which reduces the unevenness of the current density, reduces the risk of local overheating and resistance loss, and thus improves the efficiency and stability of current transmission. The detachable connection design allows the conductive member 1 and the universal connector 2 to be easily separated and reassembled. This flexibility not only facilitates rapid replacement or repair on site, but also makes the entire device easier to maintain and service. When a component is damaged or needs to be upgraded, only the component needs to be replaced or repaired, without replacing the entire device as a whole, thereby reducing maintenance costs and time. Secondly, the circular cross-section conductive part 1, combined with the detachable connection method, makes it easier for the device to adapt to different test environments and equipment. By replacing conductive parts 1 and universal connectors 2 of different specifications or types, the connection device can be flexibly adjusted to meet the requirements of specific tests or applications, increasing the versatility and adaptability of the device. In addition, since the conductive part 1 and the universal connector 2 can be detached, the entire device is more convenient to transport, and the disassembled parts can be compactly stacked or placed in a smaller space, reducing transportation costs and storage space requirements. In this solution, the conductive part 1 is a conductive rod. The conductive rod with a circular cross-section is more stable in structure and can withstand greater mechanical stress and pressure, which helps to ensure the stability and reliability of the connection device during the test and reduce failures and damage caused by mechanical stress. At the same time, the design of the conductive rod also takes into account its bending and torsion resistance, so that it can adapt to various complex test environments and connection requirements.

[0027] In a second aspect, an embodiment of the present invention provides a method for pressurizing a converter transformer valve-side partial discharge test, the method being performed using the connection device as described above. Figure 2 As shown, including: S101. Install the universal connector at the two opposite ends of the conductive part; illustratively, firstly, design a conductive part 1 of the corresponding diameter according to the voltage required for the test, and make a universal connector 2 that matches the conductive part 1, so that the connection device can flexibly adapt to different test conditions and equipment requirements, whether it is the voltage level, current size or equipment interface size, it can be met through customized design; the matching conductive part 1 and the universal connector 2 are convenient to improve the installation efficiency. At the same time, when the test requirements change or the equipment is updated, only the conductive part 1 and the universal connector 2 of the corresponding specifications need to be replaced, and there is no need to make large-scale changes to the entire connection device. Secondly, the customized conductive part 1 and the universal connector 2 can ensure the safety and reliability of the connection, avoiding safety hazards and failures caused by poor connection, excessive current or insufficient material strength. In this way, stable current transmission and a firm connection relationship improve the accuracy and reliability of the test as a whole, and reduce the test errors and the cost of repeated tests caused by equipment failure or connection problems. In terms of installation, installing the universal connector 2 at the opposite ends of the conductive part 1 can make the connection device more balanced when subjected to force. Whether it is the tension and pressure from the test device or the reaction force from the valve-side bushing of the converter transformer, it can be evenly distributed through the universal connector 2 at both ends, reducing the deformation or damage of the conductive part 1 caused by uneven force; and the balanced force state of the conductive part 1 helps to improve the stability of the entire connection device. During the test, the stable connection device can ensure the stable transmission of current, reduce the interference caused by vibration or shaking, and improve the accuracy and reliability of the test. Since the universal connector 2 itself has the ability to adjust in multiple directions, installing it at the opposite ends of the conductive part 1 can make the connection device more flexible when connected. Moreover, whether it is connected with the test device or the valve-side bushing of the converter transformer, the angle and position of the universal connector 2 can be adjusted to achieve fast and accurate docking. Finally, installing the universal connector 2 at the opposite ends of the conductive part 1 can avoid excessive concentration of stress on a certain part of the conductive part 1, thereby reducing safety hazards such as cracks and fractures caused by stress concentration. During the test, the universal connector 2 is installed at both ends of the conductive member 1. This reliable connection can ensure the stable transmission of current and the smooth progress of the test, avoiding failures or accidents caused by poor connection.

[0028] S102. Tie a sling on the conductive part to connect the conductive part to the lifting device; illustratively, first place the conductive part 1 on a mobile bracket, use the mobile bracket to transport the conductive part 1 to the work site, and then tie one end of the two slings to the appropriate positions at both ends of the conductive part 1, and connect the other end of the sling to the driving end of the lifting device, so as to ensure stability during the lifting process. During the lifting process, the sling can fit tightly to the surface of the conductive part 1 and provide uniform support force, thereby avoiding the risk of shaking or falling off of the conductive part 1 during the lifting process. During the lifting process, the use of the sling reduces the direct contact between the conductive part 1 and the lifting device, thereby reducing the risk of damage caused by friction or collision, which is of great significance for protecting the surface of the conductive part 1 and extending its service life. In terms of assembly, the sling usually has the function of quick connection and release, which makes the connection and separation between the conductive part 1 and the lifting device faster and more convenient. During the test, this helps to improve the lifting efficiency and reduce the operation time. At the same time, the sling can be customized according to the diameter of the conductive member 1 to accommodate different specifications and types of conductive members 1. Finally, the sling is usually made of soft and wear-resistant materials, such as synthetic fibers, etc. These materials can effectively protect the surface of the conductive member from scratches or wear during the lifting process. By protecting the surface of the conductive member 1 from damage, the use of the sling helps to extend the service life of the conductive member 1, thereby reducing the cost of replacing or repairing the conductive member 1.

[0029] S103, adjust the height and angle of the conductive part, and use the universal connector to connect it to the test pressurization equipment and the valve-side bushing of the converter transformer. Exemplarily, in the process of connecting with the test pressurization equipment and the valve-side bushing of the converter transformer, a fastener is used to electrically connect one of the universal connectors 2 to the pressurization equipment, and another universal connector 2 to the valve-side bushing of the converter transformer. The fastener is preferably a screw. As an important tool for connection and fixing, the fastener can ensure the stable connection between the universal connector and the pressurization equipment and the valve-side bushing of the converter transformer, and improve the safety and stability of the connection. At the same time, during the connection process, the combined use of the universal connector 2 and the fastener can disperse the stress at the connection, avoid damage caused by stress concentration, help to extend the service life of the entire connection device, and improve the reliability of the entire system. After the lifting and fixing are completed, the present solution also includes cleaning the surface of the conductive part 1 to prevent discharge interference at the tip of the conductive part 1 during the pressurization process; specifically, alcohol is used to clean the conductive part 1 to ensure that the surface of the conductive part 1 is free of impurities and smooth. As an effective solvent, alcohol can dissolve and remove impurities such as grease, dust, oxides, etc. on the surface of the conductive part 1. The presence of these impurities will hinder the smooth flow of current, resulting in increased resistance and even the formation of local discharge points. By cleaning with alcohol, the conductive performance of the conductive part 1 can be significantly improved, ensuring that the current can flow evenly and stably during the pressurization process. The surface of the conductive part 1 after cleaning is smoother, the contact area with the pressurization equipment or other conductive parts is increased, and the contact resistance is reduced, which helps to reduce the phenomena such as heat generation and arcing caused by poor contact, and improve the stability and reliability of the entire electrical system. Since the tip of the conductive part 1 is an area with high electric field strength, it is easy to form tip discharge. Impurities and uneven surfaces will aggravate this phenomenon and generate interference signals. By cleaning with alcohol, these potential discharge points can be eliminated, significantly reducing the possibility of tip discharge, thereby preventing the generation of discharge interference.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A converter transformer valve side partial discharge test pressurized lead connection device, characterized in that: include: The conductive member (1) is made of hard aluminum and has a smooth surface; Universal connecting parts (2) are installed at two ends of the conductive part (1); The universal connector (2) located at one end of the conductive member (1) is used to connect to the test device; the universal connector (2) located at the other end of the guide member (1) is used to connect to the valve-side bushing of the converter transformer.

2. The converter transformer valve side partial discharge test pressurized lead connection device according to claim 1, characterized in that: The conductive member (1) has a circular cross section.

3. The converter transformer valve side partial discharge test pressurized lead connection device according to claim 1 or 2, characterized in that: The conductive member (1) is detachably connected to the universal connecting member (2).

4. The converter transformer valve side partial discharge test pressurized lead connection device according to claim 3, characterized in that: The conductive member (1) is a conductive rod.

5. A pressure test method for partial discharge test on the valve side of a converter transformer, characterized in that: The method is carried out using the connecting device according to any one of claims 1 to 4, comprising: Install the universal connector at two opposite ends of the conductive part; Binding a sling on the conductive member to connect the conductive member to the lifting device; Adjust the height and angle of the conductive parts, and use universal connectors to connect them to the test pressurizing equipment and the valve-side bushing of the converter transformer.

6. The converter transformer valve side partial discharge test pressure test method according to claim 5 is characterized in that: Before the universal connector is installed at two opposite ends of the conductive member, the method further includes: According to the voltage required for the test, a conductive piece with a corresponding diameter is designed, and a universal connector matching the conductive piece is manufactured.

7. The converter transformer valve side partial discharge test pressure test method according to claim 5, characterized in that: The connection with the test pressurizing equipment and the valve-side bushing of the converter transformer specifically includes: One of the universal connectors is electrically connected to the pressurizing device by using fasteners, and the other universal connector is connected to the valve-side bushing of the converter transformer.

8. The converter transformer valve side partial discharge test pressure test method according to claim 5, characterized in that: Also includes: Clean the surface of the conductive parts to prevent discharge interference at the tip of the conductive parts during pressurization.

9. The converter transformer valve side partial discharge test pressure test method according to claim 8, characterized in that: The cleaning of the surface of the conductive part is specifically: Use alcohol to clean the conductive parts to ensure that the surface of the conductive parts is free of impurities and smooth.

10. The converter transformer valve side partial discharge test pressure test method according to claim 5, characterized in that: The binding slings are specifically: Place the conductive part on the mobile bracket and tie the slings at the appropriate positions on both ends of the conductive part.

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