Observation of current spikes caused by possible fast carrier transport through a low-density polyethylene sheet under high DC fields

Abstract

The repetitive current spikes caused by possible fast carrier transport through a low-density polyethylene (LDPE) sheet under high DC fields from 0.1 to 2.0 MV/cm are simultaneously measured with space charge distributions. Although a constant dc voltage is applied to the sheet between a semi-conduction (SC) electrode and an Al-evaporated electrode, large current spikes of the order of 10−8 A are repeatedly superimposed onto the dc conduction current of the order of 10−10 A. Results of the space charge measurements indicate that the charge injection from the SC anode and the subsequent deep penetration into the LDPE bulk can be observed when the current spikes are repeatedly detected. In addition, we find that a phenolic antioxidant added into the LDPE has an inhibition effect not only on the space charge penetration but also on the repetitive current spikes. This finding suggests that the antioxidant additive produces a deep trapping site for fast-moving carriers.

Analysis of Current–Voltage Characteristics in Insulating Polymers Using a Bipolar Charge Transport Model

“…Although no experimental data will be presented in the present paper, the optimized set of parameters chosen is able to reproduce most of the space charge and current measurements available for LDPE, for different experimental protocols. This set of parameters is presented in These time values are based on practices reported in the literature for polyolefins [13][14][15][16][17][18][19][20][21]. This leads to a total time of experiment varying from 18 min to 54 hours.…”

PEA measurement of low‐density polyethylene using spin‐coated P(VDF‐TrFE) film and acoustic propagation analysis based on viscoelasticity

“…Consequently, space charge accumulation is a significant obstacle to achieving long‐term use of DC transmission systems. Additionally, in recent years, there have been multiple studies 1–4 on the extremely fast charge transmission phenomenon called “Ultrafast charge.” This “Ultrafast charge” is a precursor phenomenon to insulator breakdown in polyethylene under high DC voltage.…”