Proposta para Suporte na Identificação de Rompimento e Queda de Condutores Energizados na Rede de Distribuição Primária

Abstract

In this paper, a methodology for detecting broken and downed energized conductors of medium voltage power systems is proposed. The proposed method can differentiate between the opening of one of the phases in the medium voltage in a scenario where incipient faults are generated by a downed conductor on the source side or downed conductor on the load side. This is based on an algorithm that checks the unbalance of the phase voltages measured on the low voltage side that indicates whether an open-phase has occurred at medium voltage. On the other hand, another algorithm checks the current measured in the grounding conductor of the neutral point of the distribution transformer for the existence of typical variations associated with arcing faults that occur in the medium voltage circuit. These two pieces of information define and indicate a down conductor. The first part is based on unbalancing factor calculation and the second part is based on wavelet transform to extract features from the measured current and a Frequency-Domain classifier for arcing current detection is applied. Simulations are obtained using PSCAD/EMTDC for generating data for two scenarios test cases and the detection proposed approach is implemented using Matlab software. It is necessary to emphasize that in this case we are proposing to measure and analyze the current in the grounding conductor in distribution transformers ("medium voltage to low voltage transformers"). We are not using the measured value of the ground current or residual current at the substation transformer that is normally used.