SiR dan EPDM adalah material polimer yang selalu digunakan sebagai bahan penebat di luar dan kedua-dua bahan tersebut mempunyai ciri-ciri berbeza yang diperlukan untuk menghasilkan penebat luar yang baik. Oleh itu, SiR dan EPDM dicampur bersama untuk membentuk bahan komposit yang mempunyai sifat unggul kedua-dua bahan. Nano pengisi turut dicampur untuk menghasilkan bahan penebat yang lebih baik. Walau bagaimanapun, kelembapan pencemaran di atas permukaan penebat menyebabkan konduksi meningkat dan kebocoran arus dan seterusnya menghasilkan bebad kering. Penghasilan bebad kering ini mempengaruhi pengedaran medan elektrik sepanjang penabat yang mengakibatkan arka separa dan lebihan kilat. Oleh itu, dalam kajian ini, medan elekrik sepanjang elektrod pin-satah berhampiran permukaan dielektrik tercemar disimulasi dan dianalisis menggunakan perisian analisis unsur terhingga, Comsol Multiphysics. Elektrod dnpermukaan penebat di model mengikut piawai IEC 60587. Bebad kering berlainan panjang seperti 5 mm, 15 mm, 30 mm dan 40 mm dimodel untuk menganalisis hubungan antara panjang bebad kering terhadap pengagihan medan elektrik. Dalam simulasi, tahap pencemaran diwakili oleh konduksi bahan iaitu 0.0175 S/m, 0.0500 S/m, 0.0850 S/m and 0.1500 S/m di mana masing-masing mewakili tahap pencemaran ringan, sederhana, berat dan sangat berat. Kesemua model ini disimulasi menggunakan isipadu peratusan seperti 1%, 2% dan 5%. Keputusan simulasi menunjukkan bahawa semakin pendek bebad kering menyebabkan medan elektrik bertambah di hujung pencemaran. Ia turut didapati bahawa penebat dengan isipadu nano pengisi alumina tertinggi mempunyai medan elektik terendah pada hujung pencemaran tetapi mempunyai medan elekrik tertinggi pada elektrod tanah. Selain itu, turut didapati bahawa tahap pencemaran tidak mempunyai kesan yang ketara pada medan elektrik. Ini disebabkan peningkatan kekonduksian yang digunakan terlalu kecil.
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SiR and EPDM are polymeric material that is often used as outdoor insulating material and both material has different properties that is needed to produce good outdoor insulator. Therefore, SiR and EPDM are blended together to form composite material that combined both of their superior properties. Nanofillers are also added in order to further develop the insulating material. However, the moisture of contamination on insulator surface causes increased conductivity and leakage current thus producing dry band. This formation of the dry band influences the electric field distribution along the insulator and can result to partial arc and flashover. Hence, in this work, the electric field along pin-plane electrodes near the contaminated dielectric surface is simulated and analysed using finite element analysis software, Comsol Multiphysics. The electrodes and insulating surface is modelled according to IEC 60587 standard. Dry band length of 5 mm, 15 mm, 30 mm and 40 mm is modelled to analyse the relationship of electric field distribution against dry band length. In the simulation, the severity of the contamination is presented by the conductivity of the material. Therefore, the conductivity is varied from 0.0175 S/m, 0.0500 S/m, 0.0850 S/m and 0.1500 S/m to represent light, medium, heavy and very heavy contamination, respectively. All of the model is then simulated with different volume percent of nanofiller, which are 1%, 2% and 5%. The simulation results revealed that narrower dry band create higher magnitude of electric field at the end of contamination. It is also found that insulator with 5 vol% of alumina nanofiller has the lowest electric field when compared at the end of contamination but is the highest when it is compared at the ground electrode. Other than that, it is also found that the severity of contamination is not causing any significant increase in electric field as the conductivity of contamination is not greatly varied.
Electric field analysis along pin-plane electrodes near the contaminated dielectric surface using FEM / Nurin Nadzrah Mohd Shariff