

Articles
by
N.A. Rahim 
Total Records (
3 ) for
N.A. Rahim 





N.A. Rahim
and
Z. Islam


Problem statement: The design and implementation of a sinusoidal PulseWidth Modulation (PWM) generator for a singlephase hybrid power filter is presented. Approach: The PWM was developed in an Altera® Flex 10 K Field Programmable Gate Array (FPGA) and the modulation index was selected by calculating the DC bus voltage of the active filter through a digital controller, by ProportionalIntegralDerivative (PID) technique. Results: Experiment results showed the proposed active power filter topology to be capable of compensating the load current and the voltage harmonic, up to IEC limit. Conclusion: The implemented PWM generator using an FPGA required less memory usage while providing flexible PWM patterns whether same phase, lagging, or leading, the reference voltage signal. 




R. Omar
,
N.A. Rahim
and
A. Ahmad


Problem statement: Voltage disturbances are the most common power quality problem due to the increased use of a large numbers of sophisticated electronic equipment in industrial distribution system. The voltage disturbances such as voltage sags, swells, harmonics, unbalance and flickers. High quality in the power supply is needed, since failures due to such disturbances usually have a high impact on production cost. There are many different solutions to compensate voltage disturbances but the use of a DVR is considered to be the most cost effective method. The objective of this study is to propose a new topology of a DVR in order to mitigate voltage swells using a powerful power custom device namely the Dynamic Voltage Restorer (DVR). Approach: New configuration of a DVR with an improvement of a controller based on directquadraturezero method has been introduced to compensate voltage swells in the network. Results: The effectiveness of the DVR with its controller were verify using Matlab/Simulink’s SimPower Toolbox and then implemented using 5KVA DVR experimental setup. Simulations and experimental results demonstrate the effective dynamic performance of the proposed configuration. Conclusion: The implimentation of the proposed DVR validate the capabilities in mitigating of voltage swells effectiveness.During voltage swells, the DVR injects an appropriate voltage to maintain the load voltage at its nominal value. 





M. Azri
,
M.H. Bahrom
,
N.H.A. Khanipah
,
Z. Ibrahim
,
N.A. Rahim
and
S.R.S. Raihan


This study presents the optimization of parameter operation in (PEMFC) Proton Exchange of Fuel cell
using the electrical model and the mathematical model. The parameters of the fuel cell are hard to be determine
since, the developer did not provides their parameter in details. The modelling of thermodynamic mathematical
model and the electrical model is model based on a dynamic model and both is modeled using Matlab/Simulink
simulation software by following the Horizon500 specification. The analysis of the model is model based on
the losses of the system. The cell temperature plays a role in affecting the value of losses in the model. The
input pressure plays part in affecting the stack output of the mathematical model where it is proven that a higher
pressure will produce large difference in the stack output. The efficiency for both mathematical and electrical
is below 10% less compared to the specification of Horizon500 specification thus the model parameter is
verified. 





