A technique for rapid measurement of high-voltage conductivity of dielectric liquids

Summary

The paper presents a ready-to-use experimental technique for rapid measurement of high-voltage conductivity with some examples being given to demonstrate the importance of its application. The so-called dynamical current–voltage characteristics, i.e., those obtained with the voltage modulation by a saw-tooth signal, underlie the proposed technique. Cells with blade-plane and needle-plane electrode systems are used. In such systems, the distribution of electric field strength is highly non-uniform, which lets one obtain very high values of the strength near the electrode tip avoiding the electrical breakdown of the whole interelectrode gap. Due to the rapidity of the corresponding measurements, the technique has a number of advantages. They are the possibility to carry out data acquisition under unchanged external conditions (in particular, without necessity of using a thermostat), the absence of space charge accumulation in the bulk, the possibility to verify the reproducibility of the results, etc. The experimental data were complemented with the computer simulation of the corresponding processes to reveal the features of unsteady-state current passage processes under changing voltage and to simplify the analysis of the results. Besides, the paper provides some examples of the proposed experimental technique application for measuring the high-voltage conductivity of heated liquid and in the case of presence of small mechanical impurities that actually have no effect on liquid conductivity at low voltages, but play an important role at high ones.

Additional informations

Authors

Kil Gyung-Suk, Kim Sung-Wook, Krirapee Sathit