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Surabaya, Indonesia

Bakar A.H.A.,University of Malaya | Rahim N.A.,University of Malaya | Zambri M.K.M.,Hang Tuah University
International Journal of Electrical Power and Energy Systems | Year: 2011

Power networks contain capacitances and inductances that can saturate, presenting opportunities for ferroresonance to occur. Most power equipment is designed through linear theory but ferromagnetic materials are highly non-linear and when they resonate, the non-linearity produces currents and voltages that are larger than usual. Ferroresonance is a complex, non-linear electrical phenomenon. It can cause dielectric and thermal problems through overvoltage, an intrinsic phenomenon present in all networks. A network dynamic response to lightning and switching will be energy storage and release. The transfer of energy will propagate an overvoltage through the network and damage substation equipment when lightning strikes near the substation. Application of conventional mathematics is inappropriate to ferroresonance study in which actual events are simulated. Lightning strikes that occurred near a substation and that led to explosion of CVTs have been reported, so this study investigates the effect of a lightning strike on a tower with a 132 kV Capacitor Voltage Transformer (CVT). Alternative Transient Program (ATP) was used for the simulation which duplicated the lightning-strike effect that causes a CVT to explode. Source


Hannan M.A.,National University of Malaysia | Azidin F.A.,National University of Malaysia | Azidin F.A.,Hang Tuah University | Mohamed A.,National University of Malaysia
Renewable and Sustainable Energy Reviews | Year: 2014

There are numbers of alternative energy resources being studied for hybrid vehicles as preparation to replace the exhausted supply of petroleum worldwide. The use of fossil fuel in the vehicles is a rising concern due to its harmful environmental effects. Among other sources battery, fuel cell (FC), super capacitors (SC) and photovoltaic cell i.e. solar are studied for vehicle application. Combinations of these sources of renewable energies can be applied for hybrid electric vehicle (HEV) for next generation of transportation. Various aspects and techniques of HEV from energy management system (EMS), power conditioning and propulsion system are explored in this paper. Other related fields of HEV such as DC machine and vehicle system are also included. Various type models and algorithms derived from simulation and experiment are explained in details. The performances of the various combination of HEV system are summarized in the table along with relevant references. This paper provides comprehensive survey of hybrid electric vehicle on their source combination, models, energy management system (EMS) etc. developed by various researchers. From the rigorous review, it is observed that the existing technologies more or less can capable to perform HEV well; however, the reliability and the intelligent systems are still not up to the mark. Accordingly, this review have been lighted many factors, challenges and problems sustainable next generation hybrid vehicle. © 2013 Elsevier Ltd. Source


Tokit E.M.,Hang Tuah University | Mohammed H.A.,University of Technology Malaysia | Yusoff M.Z.,University of Tenaga Nasional
International Communications in Heat and Mass Transfer | Year: 2012

An interrupted microchannel heat sink (IMCHS) using nanofluids as working fluids is analyzed numerically to increase the heat transfer rate. The rectangular IMCHS is designed with length and width of 10mm and 0.057mm respectively while optimum cut section number, n c=3. The three dimensional governing equations (continuity, momentum and energy) were solved using finite volume method (FVM). Parametric study of thermal performance between pure water-cooled and nanofluid-cooled IMCHS are evaluated for particle diameter in the range of, 30nm to 60nm, volume fraction in the range of, 1% to 4%,nanofluid type of Al 2O 3, CuO, and SiO 2 at Reynolds number range of 140 to 1034 are examined. The effects of the transport properties, nanofluid type, nanoparticle volume fraction and particle diameter are investigated on the IMCHS performance. It is inferred that the Nu number for IMCHS is higher than the conventional MCHS with a slight increase of the pressure drop. It is found that highest thermal augmentation is predicted for Al 2O 3, followed by CuO, and finally for SiO 2 in terms of Nu nf/Nu pw in the IMCHS. The Nu number increased with the increase of nanoparticle volume fraction and with the decrease of nanoparticle diameter. © 2012 Elsevier Ltd. Source


Sutikno T.,Ahmad Dahlan University | Sutikno T.,University of Technology Malaysia | Idris N.R.N.,University of Technology Malaysia | Jidin A.,Hang Tuah University
Renewable and Sustainable Energy Reviews | Year: 2014

The first and the most important step in solving the environmental problems created by cars with internal combustion engines is research and development of electric vehicles. Selection of a proper drive and optimal control strategy of electric vehicles are the major factors to obtain optimal energy management in order to extend the running distance per battery charge. This paper presents a brief review of direct torque control (DTC) of induction motors (IM) as well as its implementation for electric vehicle (EV) applications. First, the basic DTC technique based on hysteresis controllers will be introduced, and then an overview of the major problems in a basic DTC scheme will be presented and explained, as well as some efforts for improving the technique. The main section presents a critical review of DTC for EV applications, taking into consideration the vehicle mechanics and aerodynamics of electric vehicles. The review is very important to provide guidelines and insights for future research and development on the DTC of IM drives for sustainable reliability and energy efficient EV applications. © 2014 Published by Elsevier Ltd. All rights reserved. Source


Izyan Z.N.,Hang Tuah University | Shuhaimi M.,Petronas University of Technology
Energy | Year: 2014

Inefficient furnaces and heat exchangers contribute to the depletion of fossil fuel problem due to higher fuel demand and higher carbon emission. The method of exergy analysis is applied to the furnace and crude preheat train (CPT) in a crude distillation unit (CDU) to determine performance benchmark of the system. This paper presents exergy analysis and strategies to reduce exergy loss through process modification. The highest exergy loss was found to be located at the inlet furnace. The proposed options for fuel reduction strategies are reduction of heat loss from furnace stack and overall cleaning schedule of CPT. The feasibility and economic analysis for both options are investigated. From the results, overall cleaning schedule of CPT contributes to the highest energy saving of 5.6%. However, reduction of heat loss from furnace stack is the highest cost saving by about 6.4%. © 2014 Elsevier Ltd. Source

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