Abstract
This paper investigates the influence of high voltage impulses on the surface discharge characteristics of polyethylene (PE) during subsequent application of 50 Hz AC voltage. The investigation is done on two types of PE to examine the generality of the phenomena. The effect of impulses on the surface discharge features of PE are studied for both cases of having either a streamer or flashover. For each case, the consecutive surface discharges behave differently when the insulation has been exposed to the transient voltages. The effect of impulses on surface discharge of PE is shown by the change of PD numbers and phase-resolved PD patterns. The results show a prompt change in the total number of discharges which decays with the time. After a surface flashover has occurred due to the impulse, the PD behaves quite differently compared to the similar case without flashover.
Highlights
Polymeric materials have significant application in high voltage components such as cables and electrical machines and due to their good characteristics their application is increasing
The parameters shown in the results are the number of positive and negative discharges per cycle, obtained from the Phase Resolved Partial Discharge (PRPD) patterns of the surface discharges
By comparison with the Partial Discharges (PD) observed after turning off the AC voltage but without applying an impulse voltage, this change after the impulse cannot be attributed to just the lack of AC voltage: it appears to be due to the impulse
Summary
Polymeric materials have significant application in high voltage components such as cables and electrical machines and due to their good characteristics their application is increasing. Partial Discharges (PD) can influence the performance of electrical insulations in power components. Surface discharge on the insulation is one of the defects that can lead to a failure of the component. Surface discharges that appear at the boundary of insulation are a common problem for polymers used in power components. Substantial work has been done on investigation of surface potential decay of polymers and polyethylene, under corona discharge [2,3,4,5,6]. The effect of initial potential, charging time [5] and thickness [2] on charge decay has been investigated.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
