Measurements of charge carrier mobility in oil immersed paper insulation by the means of pulsed electro-acoustic method

Carrier mobility is one of the key parameter to characterize charge transportation in dielectrics. In this paper, a method based on space charge measurement technique was proposed to measure the carrier mobility in oil immersed paper. In order to obtain intrinsic carrier mobility for unipolar types, it is necessary to implement unipolar charge injection and transportation in the testing samples. For this sake, we designed a set of experiments with a barrier of dielectric. Within this method, an improved pulsed electro-acoustic system was used as well as the quantitative mapping and measurement for space charge in multi-layer dielectrics. The mobility of electron carriers and hole carriers in oil immersed paper was obtained using this method. It is also indicated that this proposed method can be generalized to measure carrier mobility in typical insulating materials.