SYSTEM AND METHOD OF DETECTION OF GROUND FAULTS IN CONTINUOUS CURRENT SYSTEMS POWERED BY RECTIFIERS.

摘要

The invention relates to a system for detecting earth faults in rectifier-fed DC systems, comprising: - an earthing impedance (6) in the transformer (1) which feeds the rectifier (3); - a device (23) for measuring the current which flows via the earthing impedance (6), obtaining a measured signal (5); - and an analysing device (15) which is responsible for analysing the measured signal (5) and includes either (i) means for obtaining the amplitude of said measured signal (5) at the network frequency, f1 (Af1), and at frequency 3xf1 (A3f1) or (ii) comparison means (10) responsible for comparing said amplitudes at frequency f1 (Af1) and 3xf1 (A3f1) with a pre-determined value (AFALLO) and obtaining at least one output signal (11,12,13) which indicates whether or not there is an earth fault and, if so, the location at which the fault occurred.