Space Charge Distribution Characteristics of XLPE/Charge Emission Shielding Layer Composite Samples

To improve the breakdown field strength of XLPE cables, an effective approach is the introduction of a charge emission shielding layer positioned between the shielding layer and the insulation layer. In this study, the melt-blending method was employed to incorporate CB into LDPE as the charge emission shielding layer, and its volume resistivity was measured. Subsequently, the PEA method was utilised to characterise the charge distribution in diverse charge emission shielding layer/XLPE composite samples under different electric field strengths and times, aiming to investigate the impact of the charge emission shielding layer. The results revealed that due to the higher volume resistivity of the emission shielding layer compared to XLPE, the introduction of this layer increased the electric field distortion in composite samples at lower field strengths. On the contrary, at higher field strengths, the emission shielding layer resulted in a more uniform electric field distribution within the charge emission shield/XLPE composite. However, the addition of excess CB to the emission shield layer increased the maximum distorted electric field in the composite samples.