Rogowski coil provides highly accurate secondary output without saturation because there is no iron core involved. The air core makes the measurement linear but delivers only a small voltage (1V instead of 100V). It enables a compact equipment arrangement and can be integrated into the GIS with little space requirement because there is no iron core. The Rogowski coil has high immunity to noises/surge voltage because the coupling factor is much lower than for a coil with an iron core.
The primary conductor in the GIS enclosure acts as the primary winding for the Rogowski coil. The secondary winding of the coil has an air core and is connected to an analog/digital converter as IED and then is connected by optical bus to the protection and control system. The
primary conductor has a high voltage potential and carries the current. It acts as the primary winding of the Rogowski coil.
The secondary windings are at ground potential at the GIS enclosure to transform the current in the primary conductor into an induced voltage of the secondary windings of the Rogowski coil .
In photo shown an electronic card then converts the measured value into a digital signal to be connected to
the control system.
