In order to distinguish own faults of nonlinear elements from their look-like faults, the paper analyses oriented energy ellipsoids of voltagechange matrices on limited accessible nodes.

The oriented energy of filter response is introduced for detecting orientation strength of vessels in that direction.

Transient radiation parameters were calculated by using the calculation formulation of transient radiated field of aperture, which included radiation energy pattern, half-energy beam-width and area-utilize coefficient, and it was for the case that the tapered circular aperture field is cophase or non-cophase with linear phase-shifting and quadratic phase-shifting excited by gauss pulse.

Traditional energy directional relay fails to discriminate fault direction in protection of the UHV long distance transmission line;and for the system resistance is too small,active energy directional relay will not work when there is fault on the outlet of transmission line.

A quadrature filter pair is designed, which consists of a steerable filter and its Hilbert transform, to analyze the dominant orientation and local orientation energy in registered images.

In this method,quadrature pair that consists of a steerable filter and its Hilbert transform is used for analysing the dominant orientation and local orientation energy in the high frequency level of each image.