A novel digital directional technique for bus-bars protection

This paper presents a novel digital technique for bus-bars protection. The technique is based on deriving a directional quantity proportional to the postfault current signal and the prefault voltage signal. The prefault current signal is also used to compensate the current signal during the current transformer (CT) saturation. The performance of the technique was investigated for a variety of operating conditions, for CT saturation, high fault resistance, source impedance, and for several bus-bar configurations. Results show that the technique is stable during early and severe CT saturations and it is able to offer very high accuracy and speed in fault detection.