Leakage currents and pollutants properties of porcelain insulators from geothermal area

This paper presents the experimental results of one new-clean and four different geothermal naturally polluted outdoor porcelain insulators. The conducted experiments were leakage current and applied high voltage measurements, in the hermetically sealed chamber, on various temperature, humidity, pressure and applied voltage. Both quantities were measured by a storage digital oscilloscope. The data could be recorded and transferred to a computer, saved in softcopy form. The leakage current waveforms were analyzed using FFT and the relation to environmental parameters were analyzed using correlation coefficient matrix and principal component analysis. The results indicated that power factors and leakage current amplitudes closed to humidity, the phase angle closed to THD, and temperature opposited to humidity. On the polluted insulator, the comparison of impedance between that on wet and dry conditions reached 0.134, as the lowest. The reached lowest phase angle and THD were 24 degree and 7,5% respectively. These phenomena occurred due to contamination on the porcelain insulator surface that make more fairly conductive. The most chemical element on EDAX test was silicon.