Space Charge In Crosslinked Polyethylene Research Articles

Effect of Electrical Trees on the Distribution of Electric Field and Space Charge in Cross-linked Polyethylene Cables

Background: Electrical trees can affect the distribution of electric field and space charge in cross-linked polyethylene (XLPE) cables, and play an important role in insulation aging and breakdown of cables. Therefore, it is important to study the influence of electrical trees in cables. Methods: In this study, the finite element method of second-order tetrahedral element and electromagnetic theory method is used for calculation. A model of XLPE cable with three-dimensional electrical trees is taken as an example for calculation. Results: The results show that the longer the trunk length is, the greater the electric field intensity at the end of the branch is; the farther the electrical trees are from the insulation side of the high voltage, the more the electric field intensity of each location decreases. Conclusion: With the increase of the resistivity of the trees, the electric field intensity and charge density tend to be stable at the end of the tree.

Space Charge Accumulation and Micro-Structure of Cross-linked Polyethylene

In this paper, laser induced pressure pulse (LIPP) method and electrostatic force microscopy (EFM) method are utilized to investigate the distribution of space charge in cross-linked polyethylene (XLPE), and the action on the groups of XLPE by the accumulative charge are investigated by infrared spectroscopy (IR) method. It was found that space charge in the sample has obvious influence on the vibration of chemical group, especially on group OH, group CH3 and group CH2. Group vibration affected considerably by space charge in XLPE sample locates on the interface between crystalline and amorphous domains. The experimental results also indicate that positive charge compared to negative charge has a different effect on bands.

Formation and Distribution of Space-Charge in Cross-LinkedPolyethylene

The formation and distribution of space-charge in a cross-linkedpolyethylene (XLPE) sample are investigated by means of pressure wavepropagation, infrared spectroscopy and electrostatic force microscopy(EFM). The related mechanism of space-charge distribution and thestructure of XLPE are discussed. The EFM images show that quite largequantitative space-charges locate at the surface of spherulites.

Thermaliy Stimulated Surface Potential Measurement Using Temperature Gradient: Polarity of Trapped Carriers in Xlpe

A new technique of thermally stimulated surface potential measurement using temperature gradient (TG-TSSP measurement) has been applied to the study of space charge in cross-linked polyethylene (XLPE) films. The open circuit voltage generated in the films has been measured, maintaining constant temperature gradient during heating. It was found that the polarity of trapped carriers injected from an electrode into the films is positive.