An alternative method for Partial Discharges measurement using digital filters

Partial Discharge (PD) or Partial Breakdown (PB) analysis is one of the most widely used methods to determine the state of electrical power insulation systems. An alternative method to measure PD is presented in this paper. In this proposed approach, data are obtained from electrical charge signals displaced by partial discharges on dielectric elements, pin type insulators. An electrical assembly consisting of a high voltage (HVAC) source, a blocking impedance, a capacitive divider and a measurement impedance was designed to obtain data. The signal detected by the measurement impedance is displayed on a high-end oscilloscope, the visualization instrument has the possibility of accessing the management software; therefore, it was possible to implement a bandpass finite impulse response (FIR) digital filter of a higher order than one hundred. The output of the filter presents the components of typical signals in partial discharges produced inside the dielectric material. Different analyzes were performed by using data segmentation which allows affirming that this approach is valid for its implementation. It this case, this method is innovative and appropriate for application in laboratories where there does not exist PD analyzers.