Mobility of charge carriers in dielectric liquids

The mobility of charge carriers in dielectric liquids is not only an intrinsic parameter of the conduction process, but it also can define the pre-breakdown processes in the liquids. The charge carrier mobility also affects the electrostatic behavior of fine and ultra-fine (micrometer and sub-micrometer) particles in -fluids, as the charge induced on dispersed particles is defined by the charge concentration and the velocity of charge carriers in the liquid. In this paper, the charge carrier mobility was obtained by measuring conduction current in different dielectric liquids under DC stress. The investigated liquids included traditional mineral oil, synthetic and natural esters. Both, single polarity and polarity reversal methods were used to obtain the charge carrier mobility in these liquids. The results show significant differences in the mobilities of charge carriers in the mineral oil and in ester liquids. Also, the effects of the electric field on the mobilities has been investigated.