Understanding the Impact of Inherent Dielectric Material Properties on PEA Output

Understanding and quantitatively analyzing space charge phenomena in dielectric materials is essential to ensure the reliability of High Voltage Direct Current (HVDC) systems. Presence of space charge in dielectrics increases local electrical fields. It is a major factor affecting insulation performance. Thus, measuring space charges is important to comprehend the processes that lead to insulation failure. Different space charge measuring techniques have been developed over the past few decades. The most widely used technique is the Pulsed Electro-Acoustic (PEA) method. Ongoing research work on PEA has proposed impact of design parameters and improvements in various signal processing techniques, both by experiments and simulations. However, this research work focuses on understanding the impact of inherent dielectric sample material properties on the measurable signal. Several materials have been studied and simulation results indicate that the acoustic wave propagation in a material is dependent upon the electro-mechanical properties of the material. The practical implication of this work is that sample properties should be considered while evaluating PEA output signals. If not considered, it may lead to inaccurate assessment of space charge profiles.