Analysis of problems in the operation of zinc oxide arrester manufacturers

Technical analysis of the damaged zinc oxide arrester in terms of operating time, installation environment, climate, and production plant

The reasons for the explosion of the zinc oxide arrester during operation can be summarized as follows:

Sealing and sealing aging problems of zinc oxide arresters:

The main reason is that the sealing technology used by the manufacturer is imperfect, or the anti-aging performance of the sealing material used is unstable. When the temperature difference changes greatly or the running time is close to the end of the product life, it will cause poor sealing and then moisture infiltration, causing internal insulation damage. It accelerates the deterioration of the resistor and causes an explosion.

Poor aging resistance of resistors:

When the zinc oxide arrester is operating at the end of its product life, the deterioration of the resistor piece causes the leakage current to rise, and even causes the internal discharge with the porcelain sleeve. When the discharge is serious, the gas pressure and temperature inside the arrester increase sharply, which causes the zinc oxide arrester body to explode and internal discharge When it is not too serious, it can cause single-phase grounding of the system.

Porcelain sleeve pollution:

Due to the zinc oxide arrester working outdoors, the porcelain sleeve is polluted by environmental dust, especially if it is installed in the substation of the metallurgical plant area, due to the large proportion of metal dust in the dust, it causes serious pollution to the porcelain sleeve and causes pollution flashover. Or due to the unevenness of the contamination on the surface of the porcelain sleeve, the current along the surface of the porcelain sleeve is unevenly distributed, which will inevitably lead to uneven distribution of the current IMOA in the resistor (or uneven distribution of the voltage along the resistor), causing the resistor to flow The current of the chip is 1-2 orders of magnitude larger than normal, which causes additional temperature rise, greatly reduces the ability to absorb overvoltage, and accelerates the deterioration of the resistor chip.

Higher harmonics:

With the influence of large-tonnage electric arc furnaces, large-scale rectifiers, frequency conversion equipment and the impact load of steel rolling production in the power grid of metallurgical enterprises, the value of high-order harmonics on the power grid has seriously exceeded the standard. Due to the nonlinearity of the resistor, when the sinusoidal voltage is applied, there are a series of odd harmonics, and when the higher harmonics are applied, the degradation speed of the resistor is even more accelerated.

Poor impact resistance:

Zinc oxide arresters often have accidents under operating overvoltage or lightning conditions. The reason is that during the manufacturing process of the resistor, due to the poor control of the quality control points of the process, the resistance of the resistor is not able to withstand square wave impact. Strong, in the process of frequently absorbing over-voltage energy, it accelerates the deterioration and damage of the resistor, and loses its own technical performance.

Yichang Hengyuan Technology Co., Ltd. is a cable connector, plug connector, high-voltage cable branch box, American elbow type head, high-voltage vacuum circuit breaker, high-voltage load switch, lightning arrester, high-voltage arrester, low-voltage arrester, arrester monitor, European-style cable connector, heat Shrinkable cable accessories, cold-shrinkable cable accessories, T-shaped heads, wall bushings, European-style cable accessories, elbow cable joints, insulators, European-style plugs, heat-shrinkable tubes, double-wall tubes, Teflon tubes, busbars Professional manufacturer of tube, cold shrink tube and other products.