Partial Discharge Measurement and Signal Analysis at Repetitive Voltage Pulses

This paper is concerned with the measurement and evaluation of partial discharges with high frequency current transformers at square wave voltages. Since these voltages are used as power supply for electrical machines, especially in the field of drive systems, twisted pairs of enameled wires are used as test samples. In addition to the complex signal acquisition, it is important to evaluate the signals. For this purpose, the analysis in the time domain, in the frequency domain by means of fast Fourier transformation and in the time frequency domain by means of wavelet transformation are presented in this work. It is shown that the voltage shape of the test voltage has only a small effect on the spectrum of the pulse in the frequency range under consideration for the investigated twisted pairs.