EARTH-FAULT PROTECTION IN MINE LOW VOLTAGE NETWORKS -- LEAKAGE PROTECTION SYSTEM TYPE RRgFx/M

摘要

To reach the optimal functional and safety parameters of central earth-fault protection, the proper recognition and estimation of the network emergency state, resulting from insulation-to-ground damage, are necessary. Many problems of earth-fault protection in networks supplying power-electronic equipment can be solved by means of a multi-parameter measuring process of characteristic quantities related to earth insulation damage. The functional-safety parameters of the RRgFx/M leakage protection system provide high safety level of the networks supplying power-electronic equipment. The RRgFx/M system ensures earth-fault protection at all sections of the network under control (also in d.c. circuits of converter). In comparison with the present protection systems used for networks with frequency converters, the system concerned is characterised by the remarkably shorter time of activation and higher resistance to disturbing transient processes of the network, caused by converter operation.