Automated digital fault recording analysis system

This paper presents the development, implementation, simulation results and field tests of an automated digital fault recording analysis system. The proposed system, which is based on measurements provided by intelligent electronic devices (IEDs) installed at the substation level and/or along the electrical networks, is capable of evaluating the behaviour of protection systems, the performance of the networks under faults and power quality events. It consists of five software modules and a humanmachine interface responsible for: reading voltage and current signals stored in COMTRADE sets of files [1], [2]; filtering the direct current (DC) decaying component of the current signals; estimating the phasor quantities and identifying the transition instants of these signals; estimating the network´s state; and presenting the results. The system is installed in “Companhia Paranaense de Energia” , one of the largest Brazilian G,T&D utility [3], and it is under evaluation.