Análise de uma proteção de linhas de transmissão baseada em ondas viajantes e transformada wavelet.

Abstract

Transmission line protection schemes using signals from two terminals are widely used in practice. However, those protection schemes should perform fairly well even when the communication from one of the terminals is lost somehow. Here, a protection scheme based on travelling waves theory using only local current signals is presented. Detection and location of faults steps are made through maximal discrete overlap wavelet transform (MODWT) due to its ability to deal with timevarying frequency signals without downsampling, suitable for real-time processing. Once the fault location is calculated, the protected zone is identified and a trip command to the proper circuit breaker is sent. The implemented methods are evaluated simulating various fault conditions with the ATP (Alternative Transients Program) and then analyzed by protection algorithms coded in MATLAB®. It shown that the implemented methods enables fast detection of fault and accurate identification of protected zones.