PEA Signal Simulation Using Multiple Viscoelastic Relaxation Model for Determination of Acoustic Attenuation and Velocity Dispersion

Acoustic attenuation in polymer insulators prevents the accurate determination of space charge profiles measured by pulsed electroacoustic (PEA) measurements. A PEA signal simulation is developed on the basis of a multiple viscoelastic relaxation model, which can determine acoustic attenuation and sound velocity dispersion in polymer insulators. To implement the multiple relaxation model, we use an analogy between the viscoelastic and dielectric relaxations. The Kelvin-Voigt model is used as a single relaxation model, and the Cole-Cole model is used as a multiple relaxation model. The simulation based on the Cole-Cole model as a multiple relaxation model can accurately reproduce measured PEA signals. The distortion of a PEA-measured space charge profile due to acoustic attenuation and velocity dispersion is also discussed. The charge profile calculated using the multiple relaxation model is in good agreement with the peak value, width, and tail shape obtained in experiments.