Space Charge Behaviour at LDPE Interface under AC Electric Stress

This paper reports on measurements of space charge characteristics in single and two-layer of low-density polyethylene (LDPE) films subjected to an applied voltage with a range of frequencies from dc to 50 Hz. Space charge was measured using the pulsed electroacoustic (PEA) technique. To measure charge distributions under ac electric fields at different angles, the point-on-wave method has been used. To obtain a good signal to noise ratio under ac conditions, the measured signals were averaged between 1000 and 2000 times. Experimental results demonstrated that frequency is a significant factor that affects bulk charge formation/distribution. In addition, interfacial charge between polymer and polymer in the two-layer arrangement was influenced by the type of electrode material