Electrothermal Aging and Electrical Properties Analysis of High Voltage PVC-Filled ZnO Microcomposites for Cable Insulation /

Abstract

Electrical cables covered with appropriate insulating material have an important role in electrical power systems. Polymeric insulators also known as polymers have widespread applications in cable insulation and indoor and outdoor insulation as well due to their versatile nature and unique properties. The polymers experience deterioration as a result of being exposed to high temperatures and voltage in their working environment. The purpose of this study is to examine the impact of zinc oxide incorporation on the electrical properties of polyvinyl Chloride and its microcomposites under accelerated electrothermal aging. This thesis aims to assess the extent of enhancement in the structural stability of polymers, electrical properties particularly dielectric properties. This is achieved by the fabrication of PVC microcomposites by using the melt compounding method. The selection of polyvinyl chloride (PVC) as the matrix material for the fabrication of the polymer microcomposites was determined based on its elastic properties, ease of processing, widespread availability, insulating capabilities, and ease of handling. Neat PVC (PZ-0) and its microcomposites with 5 % (PZ-5), 10 % (PZ-10), 15 % (PZ-15), 20 % (PZ-20), 25 % (PZ-25), and 30 % (PZ-30) of filler loading were fabricated. The microcomposites are further investigated with X-ray diffractometry (XRD). This technique evaluates how well the microfiller is mixed into the polymer matrix and how finely it is spread out. These samples were then subjected to an accelerated electrothermal aging chamber for aging purposes. Different analysis techniques were performed before and after electrothermal aging, in order to analyze and compare the electrical characteristics of neat PVC and PVC microcomposites including Visual inspection, X-ray Diffraction, STRI Hydrophobicity, Contact Angle, Optical microscopy, Leakage Current Measurement, temperature-dependent dielectric Properties, Frequency-Dependent Dielectric Properties. OM and visual analysis are used to verify any loss of material or resistance to it. Similarly, STRI and contact angle are used to determine surface hydrophobicity. The investigation proved that DC resistivity decreases with an increase in temperature. Similarly, as the samples undergo through electrothermal aging, their DC resistivity decreases because of degradation. The experimental findings indicate that the relative permittivity of a polymeric insulating material exhibits an increasing relationship with temperature, wherein greater temperatures result in an increase in the dielectric constant. The VIII microcomposite PZ-15 showed better DC resistivity and many other characteristics such as Relative permittivity, Tan Delta, etc. The effect of the addition of microfiller ZnO performed better than the neat PVC due to the intactness of the composite structure or greater surface area and surface energy. Polyvinyl Chloride and its microcomposites have proved exceptional characteristics that make them appropriate for use in electrical applications, particularly in high-voltage cables and motor insulation applications.