In the past, research on the development of breakdown mechanism has been based entirely on experiments, owning to the very complicated nature of this mechanism and it's dependency on a large number of parameters. On the other hand, the realisation of such experiments becomes more and more difficult, the higher become the voltages applied in practice. The development of an analytic model of the breakdown mechanism which is needed for the design and operation of high voltage installations.
A strong influence on the breakdown mechanism in gases, especially in atmospheric air, is exercised by their humidity, their strength varying considerably with it. By analysing the mechanism of the influence of humidity on the breakdown mechanism (Research Object No. 1), and incorporating it in the analytic model of the breakdown mechanism, it will be possible to calculate the dielectric strength of gases as a function not only of the geometric dimensions of the specimens but also of the humidity. Further, it will be possible to include in the IEC standards regulations on the influence of humidity.
Because of the very complicated nature of the breakdown mechanism of atmospheric air the acceptance of an analytic model of this mechanism depends on the veriiication of it' s accuracy by experiments. Besides, data needed for the analytic models must also be gained through experiments. In these experiments, for the carrying out of which a vast and complicated experimental set-up is regisrered and subsequently evaluated.
A prerequisite for the development of analytic models of the breakdown mechanism in air is the ability to evaluate the electric field of the gaps under investigation. In the last decades, various numerical metħods of calculation of the electric field with the use computers have been proposed, but none of them has been adequate for the rapid calculation of 411 the needed parameters of the electric field around (and on the surface) of the conductors of high voltage overhead lines. The present research program covers the existing need, by enabling the calculation and automatic registration of the named electric field. From the results of the calculation, analytic expressions are established, giving the characteristics of the electric feld as a function of the geometric parameters.
A very serious problem, having caused in the last years serious problems, is the puncture of the porcelain insulators of overhead lines. This phenomenon appears in parallel with the more usual phenomenon of the sparkover of the insulators and both phenomena are due to very steep over voltages generated in the lines.
