In the field of electrical engineering, an insulator is a material or medium that insulates against the conduction of electricity. Insulators are used in the transmission and distribution of energy, for example, in high-voltage lines, in primary components, but also in switchgear. Insulators are available in glass, porcelain or plastic with the aim of being able to secure an electrical connection without leakage currents and without a surge. Insulators are manufactured in accordance with IEC, ANSI and other certifications as a single component to a voltage level of up to 1100kV.

High-voltage lines

The lines on a high-voltage tower (e.g. Danube tower) are held in place by (triangular shaped) suspended insulators. On the other hand, in the case of a Wintrack pylon (resembling the chassis of a wind turbine), sideways protruding insulators are fitted as a V-shape and serve as support insulators to absorb both compressive and tensile forces. The high-voltage lines then usually enter a high-voltage substation via the guyed tower using insulators with a different function. It is also common to see the use of a flexible cable termination with an integrated insulator at take-off points (or points of departure) where a ground cable passes to the lines.

High-voltage substation

If we look at the primary components in a high-voltage substation, insulators are used everywhere. An insulator is therefore an indispensable component in electrical engineering for insulating the conductivity of electricity. However, support insulators are also used in high-voltage substations to safely connect rail, tube or wire to each other in order to create the various three-phase rail sections and branches to the various switch bays.

Functional requirements

The use of the various insulators mentioned is determined based on the voltage level, insulation level, pollution class, forces and application. Insulators must continue to function for their entire technical life in various weather conditions, in various operating situations regardless of whether standing or suspended. That is why strict requirements are imposed on an insulator, such as on the top transverse and tensile forces that can arise as a result of wind loads and electrical forces.

Creepage distance

In addition, depending on the insulation level (BIL) and pollution class (very light to heavy), different versions of the screens can be used to achieve the desired creepage distance. The most common creepage distances vary from 16mm/kV to 31mm/kV phase-to-phase.

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