The selection of factors and parameters affecting the quality of zinc oxide arrester manufacturers
The stability of the gap discharge voltage is the standard for the protection performance of zinc oxide arresters. There is a difference in the discharge characteristics of the rod-to-rod pure air gap and the ring-to-ring high-voltage insulator supporting gap. The former is an extremely uneven electric field, the latter is a slightly uneven electric field; the former has a slightly lower discharge voltage and less dispersion, and the latter is not only highly dispersible, but also significantly affected by the pollution performance of high-voltage insulators. When the pollution causes leakage current and reaches a certain value At this time, it forms a "voltage divider" with the leakage current of the zinc oxide arrester body, which obviously changes the potential distribution of the entire zinc oxide arrester and increases the discharge voltage value of the zinc oxide arrester. This is what the designer must give full consideration.
Test of line zinc oxide arrester manufacturer
Different from the zinc oxide surge arrester with porcelain jacket, the jacket of the composite zinc oxide surge arrester is made of organic polymer materials. It must undergo many tests to verify its characteristics, such as weather resistance test, electrical corrosion resistance test, salt spray resistance test, etc. Most of these test requirements and test methods have been reflected in the latest version of IEC standards.
Composite jacket tracking and electric corrosion test
Proportional components of zinc oxide arresters are made. The temperature of the spray chamber is 20~25℃, the NaCl content in the salt spray is 9.8kg/m3, and it is sprayed to the proportional element at a speed of 3.9L/m3·h. At the same time, the proportional continuous operating voltage Uc is applied to the proportional element for a duration of 1000h. During the test, there was no overcurrent interruption, no traces, cracks and dendritic cracks occurred in the composite jacket of the proportional element, and the umbrella skirt was not broken down.
Heat engine test and boiling test
This test is used to verify the performance of the bonding part of the flange and epoxy glass fiber cloth tube of the zinc oxide arrester under the combined action of cold, heat and mechanical force. The test is carried out in two steps:
The proportional element is tested under the following conditions at the same time: ①2 times (-35±5)℃~(50±5)℃ cold and hot cycles, high and low temperature is maintained at least 8h, each cycle lasts for 24h; ②50% is applied to the proportional element The load force of the rated tensile load.
After the proportional element is boiled in a 0.1% NaCl solution for 42 hours, it is immediately immersed in an aqueous solution at ambient temperature for 24 hours, and then placed in the ambient temperature air for 24 hours until the surface is dry.
Selection of creepage distance, cold shrinkable cable termination
The anti-fouling performance of the silicone rubber composite jacket is 66% higher than that of the porcelain jacket. This is determined by the water repellency of silicone rubber, which comes from the methyl group of silicone rubber molecules that repel water molecules. The test results show that the pollution resistance of the composite jacket is much higher than that of the porcelain jacket, but a quantitative conclusion has not yet been reached.
The improved pollution resistance of the composite jacket can be left to users and power departments as a margin for consideration. Therefore, the design of the creepage distance is still considered in accordance with the porcelain jacket standard. This design is also affected by two external factors: ①The composite jacket is easier to increase the creepage distance than the porcelain jacket, but the minimum arc distance must be guaranteed (such as ≥1m at 110kV); ②It is believed that there are two types of zinc oxide arresters with series gaps. The selection of the creepage distance should be different: there is a gap between the zinc oxide arrester body and the creepage distance ≥1.7cm/kV, which can be considered safe, because the zinc oxide arrester body hardly bears any voltage value under normal operating voltage; the insulation support has The creepage distance of the zinc oxide arrester for gaps should be the sum of the creepage distance of the zinc oxide arrester body and the creepage distance of the supporting high-voltage insulator. The author suggests that the creepage distance should be specified separately. 1.7cm/kV, because both of them have to withstand almost 100% of the overvoltage under different conditions of normal operation and the moment of lightning strike, the overall creepage distance of the zinc oxide arrester is ≥3.4cm/kV.
Yichang Hengyuan Technology Co., Ltd. is a professional manufacturer of European-style cable connectors, plug connectors, cable branch boxes, American elbows, high-voltage vacuum circuit breakers, high-voltage load switches, lightning arresters, zinc oxide arresters, tank arresters, overvoltage protectors, Counters, monitors, heat-shrinkable cable accessories, cold-shrinkable cable accessories, T-heads, wall bushings, European cable accessories, American cable joints, transformer neutral point protection devices, fuses, isolating switches, PT cable heads, elbows Manufacturers of type cable joints, 10kV outdoor terminals, switch cabinets, cable intermediate joints, cable accessories and other products
