Layered epoxy/paper composites that exhibit excellent insulating characteristics under elevated electrification and temperature conditions are essential components for power system insulation. Yet

inevitable charge accumulation occurs at hetero interfaces between layers due to interfacial polarisation and interface barrier effect

bringing about local electric field distortion and potential risk of partial discharge. A fundamental challenge is either to obtain accurate interface charge behaviours of in-service multi-layer insulating composites

or to construct verified simulating models for replacing experiments. Herein

a modified bipolar charge transport model to simulate interface charge behaviours in layered composites is proposed. With model parameters directly originated from equivalent experiments (e.g. conduction current measurement

thermally stimulated depolarisation current testing

and ultraviolet-visible spectroscopy) of epoxy/paper composites

the simulated temperature-dependent interface charge characteristics match well with pulsed electro-acoustic results. Furthermore

electrical thresholds can also be accurately calculated using such models (maximum deviation of 8.44% from experimental results)

providing references for optimised insulation structural design.