Localização de faltas em linhas de transmissão utilizando a teoria de ondas viajantes e transformada Wavelet / Fault Location in Transmission Lines Using Traveling Waves and Wavelet Transform Theory

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

This work presents a wavelet transform (WT) application to analyze the high frequency transients in a transmission line caused by a fault, with the purpose of determining its accurate location. The WT is very similar to Fourier Transform (FT), with an important difference: it allows the time determination of different frequency components of a signal. This skill allows the detection of the time of the disturbance occurrence, such as fault transients. The traveling waves generated by the fault occurrence appear as superimposed disturbances on the power frequency signals recorded by the relay. By processing these signals using the WT, the propagation time between the fault point and the relay location can be determined. Consequently, the distance of the fault point can be easily calculated. The delineated problem is boarded through the practical implementation of a computational algorithm. In this implementation, the user can choose the location technique to be employee, using data registered in one or both the terminals of the line, according to the necessity and/or availability of the data. In order to evaluate the applicability of the proposed scheme, the simulation of the transmission line in a faulty condition was utilized. This work makes use of a digital simulator of a faulted EHV (Extra High Voltage) transmission lines known as Alternative Transients Program (ATP). A typical transmission line from CESP (Companhia Energética de São Paulo) were utilized. The simulated data obtained was very close to that found in practice. This study takes into account single phase to ground faults, phase-to-phase faults, phase-phase to ground and three phase faults. The data set was composed of various fault situations considering different fault locations, fault resistances and fault inception angles. The influence of the sampled rate used was also verified as well as the mutual coupling in case of double transmission circuits. The test results reached for the algorithm are promising and demonstrate a highly satisfactory degree of accuracy and applicability of the proposed method.

ASSUNTO(S)

wavelet transform sistemas elétricos de potência transformada wavelet fault location localização de faltas linhas de transmissão traveling waves ondas viajantes power system transmission lines

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