Analysis of Mechanical Failures in High-Voltage Disconnecting Switches and Improvement Techniques
1 Common Defects and Failure Analysis
Since high-voltage power lines require daily maintenance, high-voltage disconnect switches must be frequently operated to isolate the power supply. The purpose of this is to ensure the safety of workers during maintenance. However, due to certain issues and defects inherent in high-voltage disconnect switches, investigations reveal that mechanical failures are the primary type of malfunction. For example, improper installation and debugging or mechanical corrosion can directly lead to excessively high temperatures in the conductive circuit, insulation layer fractures, and severe safety accidents. Therefore, a comprehensive analysis is necessary: identifying the root cause of failures, conducting regular maintenance, promptly detecting issues, and preventing safety incidents.
It is worth noting that the fracture of pillar porcelain insulators during operation is the most hazardous and severe mechanical failure. The causes can be analyzed from the following aspects: First, the quality of the insulator itself. If the insulator fails to meet standards and manufacturers do not strictly control quality checkpoints, significant safety hazards arise. Examination of failed fractured insulators reveals that impurities and cracks are invariably present, with inferior adhesive quality, and even the absence of asphalt as a buffer layer within the insulator. Beyond quality issues, there are also inherent design flaws, unreasonable manufacturing processes, and improper handling during the porcelain firing process. These factors result in defects at the insulator joints and flange interfaces, leading to reduced service life and poor performance. Insulators, when exposed to harsh environments for extended periods, endure intense electromagnetic radiation and corrosion, resulting in severe aging. Additionally, during seismic disasters, strong vibrations and tremors can also cause insulator fractures.
In addition to the above, the malfunction of high-voltage isolation switches is also a common fault. Improper opening and closing due to improper operation can result in poor contact, excessive resistance power, and further overheating of the circuit. The reasons for the above situations are as follows: firstly, unreasonable design or incorrect material selection; The second is severe corrosion. Due to the fact that the materials used for rotating parts are mostly metal and are exposed to outdoor environments for a long time, the outdoor climate is mostly humid, and there is a lack of lubricating oil, which leads to severe corrosion of the rotating shaft and a decrease in operational flexibility. In addition, if there is a problem with the quality of the circuit electrical components in the electric operating system, it will lead to operational failure. As most parts are made of metal materials, high-voltage isolating switches are exposed to air for a long time, and the external natural environment has a great impact on them. Adverse weather conditions such as rain and snow can accelerate the corrosion rate of their components. In addition, in recent years, the severe haze weather in China has led to an increasing humidity in the atmosphere, which has further increased its corrosiveness. Furthermore, pollutants such as dust and sand in the atmosphere react with water vapor to form highly corrosive electrolytes. If adsorbed on the surface of the isolation switch, it can cause chemical corrosion hazards. In addition to the external factors mentioned above, internal factors should not be underestimated. The mechanical components of high-voltage switches have weak sealing due to unreasonable design, internal water permeability, or errors in the selection of metal materials. The lack of selection of metals with strong corrosion resistance, or the improper workmanship of the anti-corrosion layer on the metal surface, results in the practical significance of the anti-corrosion layer being limited. In addition, the long-term lack of regular maintenance and a series of security measures can cause severe corrosion of the mechanical components of the isolation switch.
2. Improvement measures for mechanical faults of high-voltage isolating switches
Firstly, in the process of reproduction, we must firmly control the technical aspects and manufacture according to the design. At the same time, we must determine the required materials based on the design and pay attention to overall quality control. Regarding the issue of repairing broken porcelain bottles, the first thing to do is to ensure that the isolation switch meets the technical and design standards, and its design should meet the basic requirements for use. Furthermore, it is necessary to strengthen the technical control of its production process. In the production and manufacturing process, attention should be paid to selecting high-quality raw materials, and cooperation with honest and technically compliant manufacturers is required. In order to better ensure quality, contracts can be signed with manufacturers to enable them to test the quality requirements and products. In the production and operation process, on-site staff should strictly follow the production operation requirements. If there are technical errors or other faults, they should be dealt with urgently and cannot be forced to operate.
The high temperature of the circuit of the isolation switch is also a serious safety hazard, and there are many cases of affecting the normal operation of equipment due to circuit overheating. The following measures can be taken, such as adjusting the depth of contact insertion appropriately and keeping the contact clean, or introducing automatic cleaning contacts. At the same time, it is necessary to prevent high temperature phenomena in a timely manner and set up temperature detectors. Once the temperature exceeds the normal value, it needs to be dealt with in a timely manner. If we want to strengthen the cleaning force, we can use live cleaning.
In the previous fault analysis, it can be seen that rust prevention of mechanical components is very important. Therefore, regular rust prevention measures should be taken, such as timely lubrication of various components. Mechanical parts can be made of stainless steel to strengthen sealing and improve their waterproof performance. Finally, it is important to pay attention to timely maintenance and repair of mechanical components during the maintenance period. If there are safety hazards in the components, even during the maintenance period, it cannot be guaranteed that the machinery will operate normally without any malfunctions. However, one thing needs to be reminded that if repairs are only carried out to meet inspection requirements and are routine, it will not only fail to achieve the expected goals, but also cause a waste of resources. It is better not to do inefficient work.
3. Diagnostic methods for mechanical faults of high-voltage isolating switches
The characteristics of different diagnostic methods are different, and each method has its own advantages and disadvantages, which requires staff to consider which method should be used for examination based on the actual situation. The scope of inspection should be broad, including all aspects of live working and power-off maintenance, and can be compensated according to the advantages and disadvantages of various methods to achieve the goal of correct diagnosis.
Before assembly, post insulators can be inspected for cracks using ultrasound to avoid a series of safety faults such as insulator cracks. Furthermore, after the installation and adjustment of the switch, it is possible to detect whether the insulator is subjected to abnormal stress. These measures are beneficial in avoiding some safety hazards caused by congenital defects in insulators.
Regarding how to detect circuit overheating, infrared method can be used. If the detection results show local heating, the defect can be weakened according to the corresponding program.
At the same time, the motor current of the switch can be detected based on the current survey of the motor, and conclusions can be drawn to identify its severity and take appropriate measures in a timely manner. In addition to the above-mentioned detection methods, the staff also need to perform resistance strain measurement technology, which can be used to survey whether the insulator has abnormal stress conditions.
It should also be noted that the current survey system can also be used to drive the motor current signal to detect and explore whether its operation is normal. After the above detection measures have been arranged, that is, the machine can operate normally without any other safety hazards, the switch can be put into use.
4 Conclusion
This article mainly starts with the mechanical faults of high-voltage isolating switches, and analyzes a series of fault problems such as insulator breakage, abnormal stress, overheating of electrical circuits, operational failure, and corrosion of metal components.
Based on the series of technical problems faced, combined with the current situation, corresponding effective solutions for each fault are proposed.
Staff can strengthen the prevention of high-voltage insulation faults based on these suggestions to ensure the safety of their work.