Capacitance and Loss Variations with Frequency And Temperature in Composite Insulation

Abstract

Synopsis.-Variations in electrical properties of compositeTheoretical analyses are given, showing that the general form of insulation with changes in temperature and frequency are important the capacitance and loss characteristics could be cautsed by any one because they lead to concepts of physical causes of such variations of several physical mechanisms. and, therefore, indicate how to obtain improved electrical properties As a result of these studies it seems probable that in synthetic resin in commercial materials. Typical experimental data are presented laminated products semi-conducting materials in small insulated showing the capacitance and loss characteristics of synthetic resin pockets or fibers can account for observed characteristics and can be laminated materials and of imperfect composite dielectrics made represented mathematically by the Maxwell-Wagner theory. It is from combinations of fused quartz or glass and semi-conducting also shown that capacitance and loss measurements at one frequencyliquids. An example is given showing agreement between calculated and temperature cannot generally be used to predict corresponding and observed characteristics of such a glass-liquid combination.values under different conditions.

Influence of temperature and moisture on the electrical properties of leather

“…In view of the similarities in results and the characteristics of the materials, the interpretations of the present data will be patterned to some extent along the lines of the conclusions of previous workers [8,12,13,22,34,35,38,43], who have emphasized th e importance of considering interfacial polarization in electrical measurements on nonhomogeneous materials of this type.…”

“…These dipoles will represent sources of Debye polarization, an effect that is qualitatively similar to interfacial polarization. The extreme difficulty in distinguishing b etween these two phenomena has been emphasized previously [32,38].…”

“…The interface between any two of these phases is an obvious source of MaxwellWagner polarization effects. The behavior of such types of interfacial polarization has been considered in detail and d eveloped quantitatively for simple systems by other workers [32,38,39]. In leather the vast number of these interfaces present, the complexity of the interconnections of the physical matrix, and t he unknown conductivities and dielectric constants of the phases involved present a problem that permits no quantitative analysis.…”

The Thermal Evaluation of Formvar Resin

“…In some cases correlations have been found between the change in power factor with time and the life expectancy of the insulation. These are usually exceptional cases because the power factor, as a measure of loss, has meaning only when the dielectric constant does not change (4).…”

Dielectric Increments in Aqueous Solutions of Synthetic Polyelectrolytes

“…Experimental confirmation of the relative insensitivity of the Maxwell-Wagner dispersion to the geometric distribution of phases has been given by studies on a model system composed of quartz and alcohol. 18 The essential prerequisite for the Maxwell-Wagner dispersion is therefore the existence of boundaries between media of different electrical properties. Consequently we shall assume that the macroions and their associated counter ions may be represented by spherical droplets, although the actual geometry must tend toward cylindrical as dilution increases.…”