Advanced Application of Space Charge Measurement using PEA Method for Evaluation of Insulating Materials

Recently, the pulsed electroacoustic (PEA) method, which enable to measure space charge distributions in insulating materials, is applied to evaluate a performance of various electrical insulating materials. Using some improved PEA measurement systems, we can observe the space charge distributions in the materials at various temperature even under very high dc stress including a condition of electrical breakdown. In many cases, the space charge accumulation is recognized as a warning of a bad condition such as a degradation or a breakdown for the insulating materials. Therefore, by observing the space charge accumulation, we can understand the condition of the insulating materials. For such evaluation, samples are exposed to some sever accelerated conditions to confirm the degradation and the breakdown processes. In our laboratory, we have developed many types of PEA systems to make them apply to measure the space charge distributions in various samples under demanded various conditions. In this presentation, some typical examples of the advanced applications of the PEA measurement systems will be introduced with some typical spotlighted results.