Selection of synthetic insulating zinc oxide arrester manufacturers
1.1 Zinc oxide porcelain arrester manufacturer
Since the mid-1980s when the Western Porcelain Institute, the Western Porcelain Factory, and the Fu Porcelain Factory jointly introduced the world-leading MOA manufacturing technology from Japan's Hitachi, the production quality of domestic MOA has made great progress. Since the core of MOA, the zinc oxide resistor sheet, has good nonlinearity and high energy density, MOA can not only be made with gaps, but also without gaps (SICA can only be made with gaps). In addition to its good nonlinearity and high energy density, gapless MOA also has the characteristics of simple structure, fast response time, and no freewheeling, which can ensure the protection of high-voltage facilities before lightning overvoltage or operating overvoltage destroys their insulation performance. Because of the time lag effect of the gap, the gapped MOA has problems with the coordination between its gap distance and its protection characteristics. In comparison, the gapless MOA is simpler and more reliable to use. However, since there is no gap in gapless MOA, the internal zinc oxide resistor must withstand the working voltage for a long time, and the corresponding parameter selection should be appropriately adjusted. In the mid-1980s, the gapless MOA of the 10 kV power distribution system was not adjusted in time due to parameter selection. In addition, the maximum charge rate that the zinc oxide resistor sheet could withstand was low at that time, which could only reach about 50%. As a result, the accident rate of gapless MOA was high at that time. By adjusting the corresponding parameters and improving the formula and process of the zinc oxide resistor sheet, the maximum charge rate that the zinc oxide resistor sheet can withstand is increased to about 85%, thereby reducing the accident rate of gapless MOA to normal levels.
1.2 Synthetic insulated zinc oxide arrester, arrester manufacturer
Compared with SICA, gapless MOA has the advantages of large flow capacity, fast response time, and reliable protection. But their common weakness is that the porcelain jacket can only be sealed at both ends, and there is an air gap inside, making it difficult to seal reliably during mass production. According to industry statistics, under normal circumstances, more than 80% of the causes of damage to porcelain-jacketed arresters are due to moisture infiltration due to poor sealing. In 1992, people applied modern insulation technology of organic synthetic insulation to MOA and developed a new type of CMOA. In addition to the advantages of gapless MOA, CMOA also has the following advantages:
Moisture proof:Using a special material potting or integral molding process, there is no air gap inside and moisture cannot penetrate.
Explosion proof:Even if it is hit by direct lightning, the organic jacket will not explode and endanger the surrounding people and objects. At most, it will only partially crack.
Anti-fouling self-cleaning:The organic jacket is "hydrophobic" and is not easy to accumulate dirt. Even after dirt accumulates, the dirt will also become "hydrophobic", which greatly improves the lightning voltage of dirt and has better insulation performance.
It also has the advantages of small size, light weight, no damage during transportation, no rust, and very convenient installation and pre-testing. Due to the reliability of the product in protecting strong current facilities and its own high reliability, CMOA can increase the preventive test interval.
The development of CMOA has gone through three stages of improvement since 1992.
First stage:The umbrella skirt is made individually, and then bonded to form the entire jacket. Finally, special materials are poured between the positioned jacket and the zinc oxide resistor (potting type).
Second stage:Multiple sheds are made at one time, which overcomes the quality problem of insufficient bonding of a single shed during mass production (potting type).
The third stage:The organic synthetic insulating material is directly molded on the periphery of the zinc oxide resistor core to make it integrated. It overcomes the possibility that the two interfaces may slide relative to each other and cause moisture to infiltrate during long-term use due to the different thermal expansion coefficients of the three layers of materials (organic synthetic insulating jacket layer, special potting material middle layer, and zinc oxide resistor sheet innermost layer) due to weak bonding in the first and second stages of the process (integral molded type).
Yichang Hengyuan Technology Co., Ltd. specializes in the production of European-style cable joints, plug-and-pull heads, cable branch boxes, American-style elbow joints, high-voltage vacuum circuit breakers, high-voltage load switches, arresters, zinc oxide arresters, tank arresters, over-voltage protectors, counters, monitors, heat-shrinkable cable accessories, Manufacturer of cold shrink cable accessories, T-heads, wall bushings, European cable accessories, American cable joints, transformer neutral point protection devices, fuses, isolating switches, PT cable heads, elbow cable joints, 10kV outdoor terminals, switch cabinets, cable intermediate joints, cable accessories and other products
