Water Tree Simulation on Underground Polymeric Cable Using Finite Element Method

Most insulation failures in polymeric underground cables have been caused by the formation of water tree in the polyethylene insulation that leads to electrical tree. Electric field intensity is fundamental to water tree growth, hence studying and modeling water tree in a cross-linked polyethylene (XLPE) insulation is vital as insulation failure is frequently triggered by water tree. The aim of this study is to determine the electric field intensity and to identify the electric potential distribution in XLPE insulation used in the underground medium voltage cable which are affected by water tree. Finite Element Method is used to perform the simulation works. The Electrostatic numerical models of 11kV single core XLPE cable affected by the variations of water tree models and size of water tree are analyzed. The two types of water tree, vented tree and bow-tie tree are modeled in the simulation and the properties of the models were set by the experimental value found in the literature. The simulation results revealed that regardless of water tree type, size, length, shape, dimension or location, water tree contributes to higher electric field at the affected region and thus reduces the dielectric strength of cable insulation. Nevertheless, the relative permittivity, shape, length and location of water tree induce a significant variation of electric field intensity in the insulation. The electric field is found to be more intensified at the region where water tree is closer to the conductor. Therefore, electrical tree is more likely generated from the vented water tree initiated from the outer surface of the insulation that grows towards the conductor rather than the other types of water tree

Comparative Analysis of Nuclear Power Plant and Thermal Power Plants Using Analytic Hierarchy Process (AHP)

In Malaysia, fossil fuels are the most frequently used as energy resource. However, the amount of reserves for fossil fuels is now declining. That is why nuclear energy has become more popular for a certain country to diversify its production of energy. The aim of this paper is to analyze the suitability of nuclear power plant (NPP) compared to conventional power plants using a multi-criteria decision-making technique or known as the Analytic Hierarchy Process (AHP). A framework of AHP’s hierarchy is being developed, and the hierarchy structure consists of six criteria, namely safety and security, resources, public acceptance, cost of energy, construction time, and CO2 emission, respectively. Other than that, three alternatives, namely NPP, thermal power plant and hydropower plant, are also considered in the hierarchy structure. By using AHP technique, the system reveals that the hydropower plant is the most favourable choice of a better power plant compared with others. The results obtained demonstrate the validity of the framework developed

Development of Micro Hydro Power Plant Prototype as A Field Laboratory for Educational and Research Purposes

The need for cheaper electricity generation rises as the price of fossil fuels is increasingly nowadays. Hydropower plant is one of the most efficient and environmentally friendly alternative power plant sources. In this research works, a prototype of small-scale hydro power plant known as micro hydro power plant (MHPP) was developed for educational and research purpose. The motivation of this work is based on there is no field laboratory could be used for students to study the concept and actively involved in electricity generation at Universiti Teknologi Malaysia (UTM) Johor Bahru campus, Malaysia. This work hopefully become the catalyst for further research regarding renewable energy source, particularly in MHPP research. The research flow for this work begins with feasibility activities to determine some potential sites for development of MHPP at UTM Johor Campus. There are 7 (seven) potential sites based on site visits and data analysis. From the data analysis, the most suitable site chosen for MPPP prototype development. The prototype was built based on the improved design. The results show that the constructed prototype is capable for generating electricity. This prototype can be used as a field laboratory and for educational and research purpose

Optimization of Hybrid Renewable Energy in Sarawak Remote Rural Area Using HOMER Software

In past few years, there has been a huge concern about decentralized electricity supply in Sarawak, Malaysia. Renewable energy resources can be seen as an alternative energy to capture the remote rural electrification’s problems. Installing and operating a renewable energy generation is not difficult but it requires cautious step as to make sure maximum use of energy can improve the electrification. Therefore, the aim of this paper is to critically analyze five types of optimized hybrid renewable energy systems in term of financial and power production using HOMER software. This paper approaches four renewable energy resources, namely solar, hydro, wind and biomass in three remote rural areas located in Limbang, Kapit and Sri Aman regions. Different combination of solar PV system, micro-hydro generator, wind turbine and biomass generator together with battery storage and converter were studied. The optimization between these different sizes of system was built based on energy demand satisfaction, system cost and carbon gas emission. Comparison between operational of behaviors hybrid renewable energy systems with stand-alone diesel generator only were also carried out to elucidate the effects on investment cost and environment. The results revealed that hybrid hydro with battery system is seen to be the cheapest system and has the best technical performance in all locations. Solar PV and biomass generator system were combined with hydro generator as a backup power. It is also found that hybrid renewable energy is more cost-effective and reduce of carbon emission compared to standalone diesel generator. Keywords — HOMER, hybrid renewable energy resources, remote rural area, net present cost, initial cost, operating cost

Model of Grid-Connected PV System in Sarawak, Malaysia Rural Area

Sarawak is largest states in Malaysia and is gifted with lush forest and hilly terrains. However, due to this topography, Sarawak Energy Berhad (SEB) has difficulty to supply a reliable source of electricity to all areas of Sarawak. There are even areas with grid connection that occasionally suffer from power outage. Solar energy can be seen as a solution to the problem of supplying reliable power. However, installing and operating a PV system to generate power will require some insight on the location and the technical information of the PV system. Therefore, this paper aims to collect and analyze the resource data of the locations in Sarawak as well as the possible characteristics of a grid-connected PV system. The project starts with the possible locations of the PV system. The locations include area throughout Sarawak such as Sri Aman, Kapit, Limbang, Lundu, Sebuyau, Tatau and Lawas, respectively. The resource data of the area such as the average annual irradiance and the average annual ambient temperature is collected through HOMER software. The components used to test the characteristics of the PV system are CanadianSolar KuBlack C32K 300MS solar panel, Mitsubishi Electric PV-MLU250HC solar panel, Canadian Solar Single Phase String Inverter CSI-2KTL1P-GI-FL and Mitsubishi Electric Photovoltaic Inverter PVS2600, respectively. Then, the components will interchange into a combination of one PV module and one inverter to make four different sets of PV system. The result of the project revealed that the area of Limbang and Lawas is the most suitable for a Grid connected PV system because the two areas have high irradiance and low ambient temperature. The most suitable combination of components is the Mitsubishi Electric PV-MLU250HC solar panel and CanadianSolar Single Phase String Inverter CSI-2KTL1P-GIFL. This combination component has the least loss which means the PV system is efficient

Development of micro hydro power plant prototype as a field laboratory for educational and research purposes

The need for cheaper electricity generation rises as the price of fossil fuels is increasingly nowadays. Hydropower plant is one of the most efficient and environmentally friendly alternative power plant sources. In this research works, a prototype of small-scale hydro power plant known as micro hydro power plant (MHPP) was developed for educational and research purpose. The motivation of this work is based on there is no field laboratory could be used for students to study the concept and actively involved in electricity generation at Universiti Teknologi Malaysia (UTM) Johor Bahru campus, Malaysia. This work hopefully become the catalyst for further research regarding renewable energy source, particularly in MHPP research. The research flow for this work begins with feasibility activities to determine some potential sites for development of MHPP at UTM Johor Campus. There are 7 (seven) potential sites based on site visits and data analysis. From the data analysis, the most suitable site chosen for MPPP prototype development. The prototype was built based on the improved design. The results show that the constructed prototype is capable for generating electricity. This prototype can be used as a field laboratory and for educational and research purpose

Experimental Investigation on Vegetative Oils under Accelerated Thermal Ageing against Their Dielectric Strength

Insulation is one of the most important parts in high voltage apparatus such as power transformer. Most power transformer use liquid insulation material, known as power transformer oil. Petroleum-based oil so called mineral oil has been used for many years as power transformer oil. This is due to its high dielectric field strength, low dielectric loses and good long-term performance. This research work has been carried out to investigate the effect of thermal accelerated ageing on electrical properties for several vegetative-based oils. The oil samples that have been used in this research work are soy bean-based oil (FR3) and commercial palm-based oil (PFAE). As comparison, Hyrax mineral oil has also been investigated. The results revealed that vegetative-based oils have as well as dielectric strength compared with mineral oil.  It was found that the dielectric strength for all oil samples decreased when undergo the thermal accelerated ageing process

Power Transformer Fire and Explosion: Causes and Control

An increasing number of failures of power transformers over the world has led to greater interest in building up much needed expertise in electric power transformers, from its design to both preventive and prescribed maintenance. Winding failure is a frequent cause of transformer failure, bushing failure leads of fire and explosion, but it is still uncertain whether the increasing failure of transformers may be related to increasing lightning activity or increasing electric energy of the transient, surge voltages generated by lightning, especially long continuing currents and rate of rise of currents. But there are other important causes as well which need close attention, including wearing out of the contact points of tap changers in power generating and substation transformers, and poor maintenance of transformer oil. This paper seeks to review some of the well-known causes that lead to transformer fire and explosion, and highlights the important parts of the power transformer that need careful selection, installation, maintenance and condition monitoring. Moreover the containment of fires and measures that help to prevent transformer explosions in case of transformer fires are also discussed. Keywords: Embedded systems, Smart Antenna; Adaptive Array; Artificial Neural Network

Application of communication technology in Malaysian Hospital

This paper reports based on the communication technology at hospital. The focus of the paper is on describing the application of communication technology in a Malaysian hospital. Communication technology in Malaysian hospital, they are connected through e-government and ehospital. Hospital in Malaysia share the database with other hospital in order to compile and updated the database by using the appropriate system like egovernment and e hospital. Besides,this paper also organize five main communication in hospital, like wireless local area network(WLAN),medical local area network (MedLAN),voice over wireless local area network (VoWLAN),Real Time Location System(RTLS),and pagers

A study of epoxy nanocomposites insulating materials and its effects on electrical tree propagation

Polymeric insulating materials have attracted wide interest especially in high voltage equipments due to its potential properties enhancement. One of the main phenomena of partial discharges occurred in polymeric insulating material is electrical treeing phenomena. This kind of phenomena will cause excessive electric field stress at points where void and defects located. This thesis presents the thorough analysis of electrical treeing phenomena in epoxy nanocomposites. Epoxy resin nanocomposites containing 1 wt% and 3 wt%, of nanofillers sized organically modified montmorillonite (OMMT) nanoclay and silicon dioxide (silica) nanofillers were prepared and investigated, with unfilled epoxy resin served as reference material. The nanocomposites were prepared by using leaf-like specimen’s method and online monitoring method was used to test the samples. Electrical insulating properties, mainly the electrical tree resistance were investigated based on to IEC 1072:1991, “Methods of Test for Evaluating the Resistance of Insulation Materials against the Initiation of Electrical Trees”. There are three main parameters were collected during experiment was conducted which are tree inception voltage (TIV), tree breakdown voltage (TBV) and tree propagation time (TPT). Field emission scanning electron microscope (FESEM) was performed to determine the dispersion state of nanoclay epoxy resin nanocomposites. Based on the results, it was found that the existence of OMMT and silica nanofillers in polymer matrix could exhibit electrical tree growth. Furthermore, the presence of OMMT nanoclay in epoxy resin make tree growth faster compared the presence of silica nanofillers in epoxy resin