Design, Construction and Operation of the Fast Protection System of the Windings of RFX

The protection of the Windings of RFX against fast electric faults relies on an original dedicated Fast Protection System able to operate within 1 ms. The first ring of the protection chain is the fault protection system of the winding, named RGM, that consists of: about hundred highly reliable voltage and current probes, all electric signal lines and an analog-digital device where signals are processed and logic alarms are generated. RGM is an original machine that required a careful design and manufacturing work. After a long test and adjustment phase it now operates properly. It has already operated against some earth faults which, due to low level of earth current, were not dangerous for the machine but very hard to detect.