Influência do sistema de aquisição de dados sobre algoritmos de proteção de distância e localização de faltas baseados em componentes fundamentais.

Abstract

The infuence of the data acquisition system on the performance of one- and two-ended fault location techniques and on distance protection is evaluated. Basically, one Coupling Capacitor Voltage Transformers (CCVT), three anti-aliasing Ąlters, and three analog-to- digital converters (ADC) with 8, 16, and 32 bits were taken into account. Several fault scenarios are performed in a 230 kV power system modelled in the Alternative Transients Program (ATP). After each simulation, the data generated were recorded and subsequen- tly evaluated in MATLAB. Routines. In the fault location analyses, the fault point was estimated using as input data to the locator algorithms the voltage and current signals from the primary, secondary, Ąltered secondary, and the signals sampled by the ADC, and the relative errors are computed. Regarding the distance protection, the apparent impe- dance trajectory was plotted, considering the diferent signals from the data acquisition system, over the mho relay characteristics. From the obtained results, it was veriĄed that the estimated fault locations and the impedance trajectory are directly afected by the CCVT and anti-aliasing Ąlters transient responses, and the error introduced by the ADC. Furthermore, it is possible to conclude that ADC with 16 bits or more achieved identical performances for the evaluated protection functions.