Mathematical Modelling of Surface Discharge on the Contaminated Surface of Insulator Using Nernst’s Planck Equation

The outdoor insulator is exposed to the surface degradation due to the continuous electrical and environmental stresses. The contaminant flow due to the pollution that mixed with water like dew or rainwater will provide a conductive path that allowed the leakage current flow. This leakage current flow will heat-up the insulator surface and causing the formation of carbonize path due to the surface discharge. Thus, leakage current measurement had been widely used in the monitoring of surface discharge phenomena and to understand the insulator surface condition. However, study on the physical process of discharge phenomenon that leads to the conductive path and breakdown on the insulator are not well concerned and understood. Therefore, this study is concerned with modelling of surface discharge on the contaminated surface of insulator including the charge transport and generation mechanism. This model is used electro-migration model and considered the electric field dependent molecular ionization as the generation mechanism of charge carriers. The charge carrier generation and transport mechanism are accounted with the Nernst Planck theory to model the behaviour of the charge carriers while Poisson’s equation is used to determine the distribution of electric field on the insulator surface. A mathematical model of surface discharge on the insulator based on the Nernst Planck Theory is then discussed

Comparison of Torque Performances on Different Core Material for Switched Reluctance Actuator without Permanent Magnet

This paper presents the comparison of torque profiles of the Switched Reluctance Actuator (SRA) without permanent magnet (PM) using two types of materials which are Low Carbon steel, Grade 1008 and Medium Carbon steel, Grade S45C. Each of the Low Carbon steel and Medium Carbon steel is distinguished by the percentage of carbon contents which is 0.1% and 0.43%, respectively. The designed SRA of both materials was according to the size of NEMA 17 standard stepper motor for small machine applications and simulated through FEM analysis. The maximum generated torque achieved by the SRA with the Low Carbon steel is 122.540mNm and with Medium Carbon steel is 54.107mNm, respectively at 2A input current. It shows that the carbon content influences the magnetic properties of the materials as the generated torque decreases approximately 50% when the carbon content is four (4) times higher. As a conclusion, the Medium Carbon steel, Grade S45C depict better working range as it capable of generating high torque at a small overlapping angle compared to Low Carbon steel, Grade 1008

Optimization of the force characteristic of rotary motion type of electromagnetic actuator based on finite element analysis

The needs for non-invasive technique in breast cancer detection could enhance and preserve the future of medical field in Malaysia as well as countries around the world. Breast cancer has become the main concern nowadays not only for women but for man as well. In overall, the risk of women getting breast cancer is higher than man due to the denser tissue of breast in women compare to man. Beside the unawareness for the disease, the reason which contributes to this increasing number of breast cancer reported is also due to the limitations arising from modalities such as MRI, Mammography, ultrasound and other modalities. An alternative to current technologies should be improved for early detection and treatment which causes no physical harm to patients if possible. Thus, non-invasive and better technology in detecting breast cancer is very much needed in the current market. This paper will be discussing the insights of Magnetic Induction Tomography techniques in breast cancer detection

Comparison of torque performances on different core material for switched reluctance actuator without permanent magnet

This paper presents the comparison of torque profiles of the Switched Reluctance Actuator (SRA) without permanent magnet (PM) using two types of materials which are Low Carbon steel, Grade 1008 and Medium Carbon steel, Grade S45C. Each of the Low Carbon steel and Medium Carbon steel is distinguished by the percentage of carbon contents which is 0.1% and 0.43%, respectively. The designed SRA of both materials was according to the size of NEMA 17 standard stepper motor for small machine applications and simulated through FEM analysis. The maximum generated torque achieved by the SRA with the Low Carbon steel is 122.540mNm and with Medium Carbon steel is 54.107mNm, respectively at 2A input current. It shows that the carbon content influences the magnetic properties of the materials as the generated torque decreases approximately 50% when the carbon content is four (4) times higher. As a conclusion, the Medium Carbon steel, Grade S45C depict better working range as it capable of generating high torque at a small overlapping angle compared to Low Carbon steel, Grade 1008