Effect of Cross-linking Agent Content on Dielectric Properties of PP Films Modified by EB Irradiation for HVDC Capacitor

• Published in: IEEE transactions on dielectrics and electrical insulation 2024-11, p.1-1
• Main Authors: Xiao, Meng, Chen, Yuyan, Liu, Haoliang, Du, B. X.
• Format: Article
• Language: English
• Subjects: cross-linking; dielectric properties; electron-beam irradiation; Film capacitor; polypropylene
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2024.3502000

The decline in breakdown strength and the rise in dielectric loss of polypropylene (PP) film at high temperatures are the key factors restricting the application of metalized film capacitors (MFCs). This paper proposed a modification method using electron-beam (EB) irradiation to improve the high-temperature insulation performance of PP film for capacitors. The influence of cross-linking agent contents on the dielectric properties of irradiated cross-linked PP is investigated. The results show that the conductivity of EB-irradiated films doped with 0-2 wt% PETA is reduced by 26.9%-60.8% and the breakdown strength is enhanced by 2.8%-21.2% at 125 °C, resulting in better dielectric properties compared to pure PP films. The formation of a three-dimensional network structure by cross-linking can inhibit the thermal motion of molecular chains and improve their thermal stability, consequently limiting the transport behavior of carriers. Irradiation cross-linking modification can improve the high-temperature dielectric properties of PP films. This research provides a valuable reference for the cross-linking modification of PP films serving in MFCs.