Analysis of problems in operation of zinc oxide arrester manufacturers
Conduct a technical analysis of damaged zinc oxide arresters in terms of operating time, installation environment, climate, and production plant.
The reasons for the explosion of zinc oxide arresters during operation can be summarized as follows:
Zinc oxide arrester sealing and seal aging issues:
The main reason is that the sealing technology used by the manufacturer is imperfect, or the sealing material used has unstable anti-aging properties. When the temperature difference changes greatly or the operating time is close to the end of the product life, the sealing is poor and moisture infiltrates, causing internal insulation damage, accelerating the deterioration of the resistor and causing an explosion.
The resistance film has poor anti-aging performance:
When the zinc oxide arrester runs in the later period of its product life, the deterioration of the resistor causes the leakage current to increase, and even causes internal discharge with the porcelain sleeve. When the discharge is serious, the gas pressure and temperature inside the arrester increase sharply, causing the zinc oxide arrester body to explode. When the internal discharge is not serious, it can cause the system to be grounded in a single phase.
Porcelain sleeve pollution:
Since the zinc oxide arrester works outdoors, the porcelain sleeve is polluted by environmental dust, especially if it is installed in a substation in a metallurgical factory. Since the proportion of metal dust in the dust is large, it causes serious pollution to the porcelain sleeve, causing pollution flashover or uneven distribution of the current along the surface of the porcelain sleeve due to uneven pollution on the surface of the porcelain sleeve. This will inevitably lead to uneven distribution of the current IMOA in the resistor sheet (or uneven distribution of the voltage along the resistor sheet), making the current flowing through the resistor sheet larger than normal. 1-2 orders of magnitude, causing additional temperature rise, greatly reducing the ability to absorb overvoltage, and also accelerating the deterioration of the resistor.
Higher harmonics:
With the impact of the application of large-tonnage electric arc furnaces, large-scale rectifiers, frequency conversion equipment, and the impact load of steel rolling production, the high-order harmonics on the power grid have seriously exceeded the standard. Due to the nonlinearity of the resistor, when the sinusoidal voltage is applied, there are still a series of odd harmonics, and when high-order harmonics are applied, the deterioration of the resistor is 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 sheet, the quality control points of each process are not strictly controlled, which makes the resistor sheet not strong enough to withstand square wave impact. In the process of frequently absorbing overvoltage energy, the resistor sheet is accelerated to deteriorate and damaged, and loses its own technical performance.
Yichang Hengyuan Technology Co., Ltd. specializes in cable joints, plug-and-pull heads, high-voltage cable branch boxes, American elbow joints, high-voltage vacuum circuit breakers, high-voltage load switches, lightning arresters, high-voltage arresters, low-voltage arresters, arrester monitors, and European cable joints , professional manufacturer of heat shrink cable accessories, cold shrink cable accessories, T-shaped heads, wall bushings, European cable accessories, elbow cable joints, insulation parts, European plug-in and unplug heads, heat shrink tubes, double-wall tubes, Teflon tubes, busbar tubes, cold shrink tubes and other products.
