A new approach for discriminating between switching and fault generated broadband noise on EHV transmission lines

A novel technique for the detection of fault generated high frequency noise on transmission lines has been under development within the Power and Energy System Group at Bath University. The technique employs an arrangement involving the use of conventionally connected power line communication signal traps and capacitor voltage transformers (CVTs). This paper examines the performance of the digital fault detection technique in the presence of high frequency signals due to both arcing faults and spurious noise, with a view to improving the reliability and dependability of the technique, particularly in the presence of the latter. The performance is illustrated in relation to high frequency responses attained from a typical 400 kV vertical construction line, under both faults and switching operations on the system and for these purposes, the simulation studies for generating the high frequency phenomenon includes the incorporation of very realistic nonlinear arc models. The well known EMTP software package is used.<>