PRODUCT DETAILS

GIS lightning arresters use sulfur hexafluoride (SF6) as an insulating medium and are used in power systems with rated voltages of 66kV to 765kV and rated frequencies of 50Hz. During operation, the transmission, transformation, and distribution equipment in the power system must not only withstand long-term working voltages and temporary overvoltages caused by ground faults, load reduction, resonance, etc., but also withstand lightning overvoltages and operating overvoltages. Among them, lightning overvoltages and operating overvoltages may have very high values. Simply relying on improving the insulation level of equipment to withstand these two overvoltages is not only economically unreasonable, but also often technically impossible.

A positive approach is to use electrical appliances that specifically limit overvoltages to limit overvoltages to a reasonable level, and select the corresponding equipment insulation level accordingly. Lightning arresters are the most important type of electrical appliances that limit overvoltages. The widespread use of metal oxide lightning arresters effectively limits lightning overvoltages and operating overvoltages on electrical equipment.

Gas-insulated metal-enclosed lightning arresters (GIS lightning arresters) are lightning arresters that can be directly connected to combined electrical appliances. GIS arresters use sulfur hexafluoride (SF6) as the insulating medium and are used in power systems with rated voltages of 66kV to 765kV and rated frequencies of 50Hz. The metal jacket of this type of arrester is generally made of aluminum or steel. Since the connection of the GIS gas chamber is specified by the manufacturer and is not standardized, the connection of the GIS arrester is also the same. Therefore, GIS manufacturers generally have their own GIS arrester designs, which can be connected to different GIS and arresters on the market with the help of adapter flanges. The most significant difference in GIS arrester design is the number of phases in the same tank. When the system voltage is lower than 220kV, a three-phase tank design is usually used; when the system voltage is higher, a single-phase design is usually used.

Compared with AIS arresters, since the nonlinear resistor column of GIS arresters is more seriously affected by the capacitance to ground, if special measures are not taken, the voltage distribution along the nonlinear resistor column will be extremely uneven, so the voltage equalization system inside the GIS arrester is more complicated than that of the AIS arrester.

In addition, when the system voltage is higher than 220 kV, in order to reduce the geometric height of the nonlinear resistor column, the internal design of the functional element is: a three-column/four-column spiral structure is used mechanically, and a single-column structure is used electrically. In order to achieve mutual insulation between nonlinear resistor layers, an insulating pad with extremely high insulation strength must be used.

1) The product insulator plug-in is directly connected to the power grid system and withstands the high voltage of the power grid;

2) The shell is made of aluminum alloy and contains main components such as iron core and shielding;

3) The main component of the iron core is the resistor, which is an important component of the product to protect electrical equipment;