Patent ID: 8744637

Claim:
A method of detecting an instance of fault clearance, or distinguishing a temporary versus permanent fault, or detecting a healthy condition in a shunt reactor compensated transmission line consists of following steps, wherein each step could be independently practiced by an entity with a product or a service of one's own or another entity to accomplish each step: determining a set of unique characteristics expressed by the transmission line with shunt reactor system during fault, secondary arc and fault cleared states for each type of fault; determining a set of parameters including non-leakage window lengths, acceptable spectral leakage window lengths, modal transformation matrix, time period and frequency for each fault state and type to facilitate accurate feature extraction; determining a set of feature extraction algorithms along with associated settings, threshold values, and settling times using said set of parameters, wherein said set of feature extraction algorithms either independently or in combination, are used to extract said set of unique characteristics to detect fault state or state transitions; and implementing the said algorithms in systems including protection relays, disturbance monitoring equipment, standalone systems comprising analog, digital, discrete, and memory systems, wherein the said extracted set of unique characteristics from the said feature extraction algorithms are compared against known values representing the said unique characteristics to detect the fault state, or a sudden change in the said extracted set of unique characteristics from the said feature extraction algorithms is used to detect a state change, and wherein the said associated settling times and threshold values are used to qualify the detection of the fault state or the state transition.