Investigation of wide-range trap energy spectra of typical aerospace polymer dielectric materials by using photo-stimulated discharge method

The presence of space charge in polymer insulation materials has emerged as a critical constraint in the advancement of polymer materials for high-voltage electrical devices. Trap properties play a pivotal role in governing the storage and transport of space charges. Thus, precise characterization of the distribution of charge trap energy spectra in polymer dielectric materials holds immense scientific significance for enhancing the properties and applications of such materials. In response, the author develops a platform utilizing the photo-stimulated discharge (PSD) method to measure the trap energy spectra of polymer dielectric materials. This platform allows for accurate, intuitive, and effective characterization of trap parameters across a broader range while preserving the original features of trap energy levels. Experimental results have shown that the laser light source employed in the platform does not induce photodegradation or photodamage to the tested samples. The validity of the PSD measurement system has been confirmed under diverse experimental conditions, yielding trap spectra and pertinent parameters for four representative polymer materials: polyimide, polyester, polyvinylidene fluoride, and polyethylene. This work presents a scientifically effective approach to characterize trap energy spectra in polymer dielectrics, providing valuable insights into the characterization of such spectra.