High Impedance Fault Identification by Cyclostationary Feature Analysis
High impedance fault, analysis cyclostationay, distribution systems
Conventional overcurrent protection systems are often not sensitized to the occurrence of high impedance faults, because they have a low amplitude. This type of disturbance causes damages to the concessionaires, as well as can cause damages to the lives of people and/ or animals. Therefore, different identification methods of high impedance faults in electric power distribution systems have been proposed. The main difficulty found by these methods is due to noise interference on the signal, as well as the low fault overcurrent level. Therefore the search for efficient and reliable method to identify high impedance faults, which does not present the drawbacks found in the methods proposed in the literature, an innovative method is proposed that minimizes the noise interference on the signal, and uses characteristics Statistics present on the signals with lack of high impedance to identify them, and thus to differentiate them from other phenomena present in the electrical systems. Specifically, the method uses analysis of cyclostationary processes to extract cyclic autocorrelation information from the samples of the signals of interest by calculating the cyclic spectral density function. From this information, we can obtain descriptors that allow to classify at a later stage the faults of high impedance. Preliminary results indicate that the method is robust to noise and efficient in terms of correct classification rate of high impedance events.