Abdul Rahim Abdul Razak

Proteus based simulation of a charge controller

This paper provides the simulation aspect of a newly design charge controller in Proteus Isis environment. The system function by to managing battery (for two batteries) charging scheme by regulating incoming source. The sensing method only employs voltage reading from source. Since the research is at initial stage, it is therefore conducted in an adequate manner by completing each stage at fundamental basis.

Properties of Lightweight Concrete Composites with Mixture of Fly Ash and Concrete Sludge Aggregate

Lightweight foamed concrete is a concrete made by cement slurry mixed with foam so that foamed concrete that is much lighter than conventional concrete can be produced. The objectives of this study is to develop optimal pre-foamed lightweight foamed concrete and to achieve desired density of lightweight concrete that is below 2400 kg/m3. Three samples of concrete were batching with 0%, 25% and 50% of foam respectively under mixing ratio of 1:1:2 and foam dilution ratio 1:5 to obtain optimum result. Based on the result attained, the samples achieved the bulk density ranged from 1943 kg/m3 to 2305 kg/m3. In addition, other physical characteristics of this mixture of materials show that its water absorption for all the samples was increased from 6.508% to 11.889%. This trend of results was obtained if the volume of foam presented in the concrete were increased. Furthermore, the samples achieved compression strength ranged from 22.418 MPa to 32.229 MPa with presence of foam. In summary, with additional of fly ash and concrete sludge as aggregate it can help to produce comparable concrete composites with lighter density.

A conceptual implementation of a buck converter for an off-grid hybrid system consisting of solar and wind turbine sources

A hybrid renewable power generation system is proposed through parallel connection between two potential energy resources: photovoltaic (PV) and wind turbines. The method consists of incorporating a buck converter connected by a wind turbine to provide adjustment according to PV potential. Unlike the conventional buck-boost converter topology that is normally used, this research tries to emphasize the use of a buck converter as part of the system configuration. Design schemes were carefully performed and the postdesign system was tested through system simulation with MATLAB/Simulink software. The simulated system offers promising and significant results, thus making it suitable for hardware implementation.

Simulation of Microcontroller Based Perturb and Observe MPPT Controller for Photovoltaic Energy Applications

This paper demonstrates the implementation of P&O MPPT controller. The proposed controller was written and compiled in mikroC and later incorporated to a low cost PIC18F4550 microcontroller. Open loop simulation using Proteus Isis was conducted to test the effectiveness of the proposed algorithm. Results obtained from simulation proved the effectiveness of the proposed controller making it suitable for hardware implementation.

Effect of NaOH concentration on microstructure of boiler ash based geopolymer

Boiler ash is one of the waste material from palm oil processing industry and it was widely available. The role of alkaline activator in geopolymer is important for its mechanical properties. NaOH and sodium silicate solution was used as alkaline activator. In order to investigate effect of NaOH concentration on microstructure of boiler ash based geopolymer 6 different NaOH concentration (6M, 8M, 10M, 12M, 14M, 16M) were used. The boiler ash based geopolymer samples were cured in oven at temperature 80 °C for 24 hr. The compressive strength of geopolymer samples at 7 days showed that 14M obtained the maximum strength (13.9 MPa). This result was supported with SEM analysis were the 14M geopolymer sample showed more dense geopolymer matrix compared to others.

Core loss characteristics analysis of power transformer under different frequencies excitation

This paper presents a simplified method for determination the separation of hysteresis and eddy current losses characteristic of power transformer. The model tuning is performed by energized the transformer core in no-load condition with sinusoidal voltage waveform, different frequencies and the magnetic flux density in transformer core always constant maintained. The core loss splitting is obtained by using two-frequency method. The results show that at low frequency, the appearance of hysteresis loss is visible, but at higher frequency, the eddy current loss is more significant.

Effects of DC line voltage environment on different types of compact fluorescent lamps operation

Compact fluorescent lamps are tested under DC operating conditions. Five random samples are evaluated in term of their starting and operation response compared to normal AC environment. Experiment result shows that DC line supply has successfully able to start and operate any conventional CFL at almost the same lux level and power consumption rate of 240ac rms.

Effect on Strength and Hardness of Clay Ceramic Substrate after Treatment Using Koalin Based Geopolymer Glaze

Geopolymerization is an alternative for ceramic industry by using clay based material such as kaolin or calcined kaolin geopolymer. Geopolymer paste is initially produced by alkaline activation of calcined kaolin with NaOH and Na2SiO3 solution), dried at 80oC for 4 hours, pulverized and sieved to fixed particle size powder. The parameters involved in this processing route (alkali concentration, kaolin or calcined kaolin to activator ratio, alkali activator ratio and heating conditions) are investigated. Geopolymeric powder is added with water to produce slurry to be coated on the surface of clay ceramic. It undergoes heat treatment at high temperature to produce glaze on the surface. Flexural strength and hardness analysis are studied. Result evidences the processing show of incresing strength value between 8-10% after treatment with geopolymer glaze and also the Vickers hardness values of geopolymers improved.