A novel setting-free method for fault classification and faulty phase selection by using a pilot scheme

Accurate fault classification and swift faulty phase selection are the bases of protection for transmission systems. The classification and selection process should be done as fast and reliably as possible. In order to reduce the time required for fault classification and faulty phase selection, traditional methods cannot work well and it is necessary to use sophisticated ones. Besides, settings necessary for these methods in order to properly work always present challenge. This paper presents a new fault classification and faulty phase selection method using reactive power features during normal condition and after fault inception. It will be demonstrated that during faulty conditions the reactive power of faulty phase measured at the ends of line will be positive whereas under non-faulty conditions this feature is not held. By using this specific feature and a pilot scheme the method will work without setting any threshold for any parameter. The simulations done by MATLAB^® will verify the performance of the proposed method.