Mohd Rafi Adzman
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Preferred name
Mohd Rafi Adzman
Official Name
Mohd Rafi , Adzman
Alternative Name
Adzman, M. R.
Adzman, Mohd Rafi Bin
Adzman, Mohd Rafi
Main Affiliation
Scopus Author ID
16833392100
Researcher ID
AAF-8313-2019
F-8971-2017

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Fault localization and detection in medium voltage distribution network using adaptive neuro-fuzzy inference system (anfis)

2021-01-01 , Jamili N.S.B. , Mohd Rafi Adzman , Salman W.S.A.W. , Muhd Hafizi Idris , Melaty binti Amirruddin

This paper provides an overview method of ANFIS to improve the performance of locating and detecting a single line to ground fault in medium voltage (MV) distribution power system network. For this research, the proposed method used faulted current signals from the network as an input in ANFIS to obtain the expected fault location and detection. In order to accurately locate the faults in the network, an ANFIS was trained and tested using various sets of data, which was obtained from the simulation of faults at various fault scenarios such as inception angle, load, fault location, and fault resistance. Based on the result obtain, the fault distance, major and minor branch of the single line to ground fault can be located with minimal error.

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Two-terminal fault detection and location for hybrid transmission circuit

2021-08-01 , Muhd Hafizi Idris , Mohd Rafi Adzman , Mokhlis H. , Mohammad Faridun Naim Tajuddin , Haziah Abdul Hamid , Melaty Amirruddin

This paper presents the algorithms developed to detect and locate the faults at a hybrid circuit. First, the fault detection algorithm was developed using the comparison of total positive-sequence fault current between pre-fault and fault times to detect the occurrence of a fault. Then, the voltage check method was used to decide whether the fault occurred at overhead line (OHL) or cable section. Finally, the fault location algorithm using the impedance-based method and negative-sequence measurements from both terminals of the circuit were used to estimate the fault point from local terminal. From the tests of various fault conditions including different fault types, fault resistance and fault locations, the proposed method successfully detected all fault cases at around 1 cycle from fault initiation and with correct faulted section identification. Besides that, the fault location algorithm also has very accurate results of fault estimation with average error less than 1 km and 1%.

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A Hybrid Optimization Approach for Power Loss Reduction and Voltage Profile Improvement in Distribution System

2022-01-01 , Noor Najwa Husnaini Mohammad Husni , Siti Rafidah Abdul Rahim , Mohd Rafi Adzman

In the past decades, the electrical power system is designed and developed to satisfy the owner demand that continuously appears in many variations. Hence, engineers have put their full effort to solve the problem associated with electrical power systems that come and might arise in the future. Therefore, distributed generation (DG) has been introduced to solve multiple electrical power system problems. The proposed methodology presented in this study focuses on minimizing network power losses, improving the voltage profile of system operation, and security constraints in a distribution. It is known that the location and capacity of DG play significant roles in the system losses in a distribution system. A hybrid metaheuristic nature-inspired algorithm is presented in this study for optimal location and sizing of multiple DG units. The best location and optimal sizing of DGs will be determined through Hybrid metaheuristic of Artificial Immune System Firefly Algorithm (AISFA). The designated technique will be tested into IEEE-69 test system using MATLAB software. For reducing the power losses, the simulation results have shown that bus 61 is the best location for reducing power losses and improving voltage profile in IEEE-69 test system in the preliminary result. By installing DG at bus 61, the real power losses improve about 89%, with a voltage profile improvement index up to 1.249099.

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Neural Network based Transmission Line Fault Classifier and Locator using Sequence Values

2023-01-01 , Muhd Hafizi Idris , Mohd Rafi Adzman

Faults can easily occur at transmission line because the line is exposed to the environment. The fast fault location after a fault occurrence will minimize the time to repair the faulty part thus reduce the stress of power system due to long outage time. This paper demonstrates the development of fault classifier and fault locator using neural network. The positive, negative and zero sequence values of three-phase voltage and current during fault time were used as the inputs to train the neural networks. Various fault conditions which have different fault types, fault resistance values and fault locations have been simulated to generate the training data for both neural network based fault classifier and fault locator. From the results, the fault classifier and locator successfully classified and located all the simulated fault conditions. One of the advantages of using sequence values as the inputs for the neural networks is only one fault type need to be simulated and used as the training data for single line-to-ground fault (RG, YG and BG), line-to-line fault (RY, YB, BR) and double line-to-ground fault (RYG, YBG, BRG).

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An integrated of hydrogen fuel cell to distribution network system: Challenging and opportunity for D-STATCOM

2021-11-01 , Khaleel M.M. , Mohd Rafi Adzman , Samila Mat Zali

The electric power industry sector has become increasingly aware of how counterproduc-tive voltage sag affects distribution network systems (DNS). The voltage sag backfires disastrously at the demand load side and affects equipment in DNS. To settle the voltage sag issue, this paper achieved its primary purpose to mitigate the voltage sag based on integrating a hydrogen fuel cell (HFC) with the DNS using a distribution static synchronous compensator (D-STATCOM) system. Besides, this paper discusses the challenges and opportunities of D-STATCOM in DNS. In this paper, using HFC is well-designed, modeled, and simulated to mitigate the voltage sag in DNS with a positive impact on the environment and an immediate response to the issue of the injection of voltage. Furthermore, this modeling and controller are particularly suitable in terms of cost-effectiveness as well as reliability based on the adaptive network fuzzy inference system (ANFIS), fuzzy logic system (FLC), and proportional–integral (P-I). The effectiveness of the MATLAB simulation is confirmed by implementing the system and carrying out a DNS connection, obtaining efficiencies over 94.5% at three-phase fault for values of injection voltage in HFC D-STATCOM using a P-I controller. Moreover, the HFC D-STATCOM using FLC proved capable of supporting the network by 97.00%. The HFC D-STATCOM based ANFIS proved capable of supporting the network by 98.00% in the DNS.

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Evaluation of fault location algorithm in distribution power system lines using differential equation method with fault indicator approach

2022-01-01 , Izatti Md Amin , Mohd Rafi Adzman

A malfunction in any electrical system network will eventually happen. Damage and minor problems are less likely to develop if a problem can be resolved quickly. As a general rule, fault location is a procedure of aiming the location fault at the maximum feasible accuracy. In order to locate faults in distribution lines for multi-ended power systems, this work provides a single line to ground (SLG) fault location algorithm employing a differential equation (DE) with a fault indication approach. The overall distribution lines modelcombines the generalized compact models of all homogenous line sections. Furthermore, this study approached fault indicator equipment as an indicator during every section fault. Hence, the ATP Draw has simulated the medium voltage distribution linesconsisting of overhead lines (OHL) and multiple underground cable lines (UCL). The evaluation of the method considered the parameter of fault resistance, fault distance, and fault inception angle. The results show that the fault location algorithm using DE fault location algorithm with fault indicator information produced the most accurate result.

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Influence of flow accelerated corrosion on corrosion protection of mild steel in 3.5% NaCl solution

2024-03-07 , Mahalaksmi Gunasilan , Shaiful Rizam Shamsudin , Mohd Rafi Adzman , Siti Hawa Mohamed Salleh , Wan Mohd Haqqi Wan Ahmad , Mohamad K.A.A.K.

Mild steel is a primary material used to construct ships and other maritime structures. Corrosion protection systems are sometimes ineffective in aqueous mediums subjected to movement, flow, waves, and even turbulence under unpredictable conditions. This study aims to ascertain the influence of flow velocity on mild steel corrosion in the aqueous medium. The mild steel samples are immersed in a 3.5% sodium chloride (NaCl) solution for five days. They were protected against corrosion using an impressed current cathodic protection (ICCP) system. The flow velocity is increased to 200-800 rpm, while the stationary flow is also examined as a control. Data on the metal's potential and current density were collected, and the surface morphology was analyzed using a stereomicroscope. Corrosion protection occurs exclusively in stationary flow, whereas corrosion occurs in solutions flowing at a most studied velocity. Metals show corrosion severity levels ranging from 200 to 600 rpm with increasing current consumption and metal potential. At 800 rpm, the metal surface appears to begin passivating, reducing the current consumption and potential. The flow velocity accelerates corrosion, yet at the high-speed stream, the corrosion is slowed because the steel surface becomes passive and assists the corrosion protection.

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A hybrid multi-objective Evolutionary Programming-Firefly Algorithm for different type of Distributed Generation in distribution system

2022-12-01 , Noor Najwa Husnaini Mohammad Husni , Siti Rafidah Abdul Rahim , Mohd Rafi Adzman , Hussain M.H. , Musirin I. , Syahrul Ashikin Azmi

With the rise in electricity demand, various additional sources of generation, known as Distributed Generation (DG), have been introduced to boost the performance of power systems. A hybrid multi-objective Evolutionary Programming-Firefly Algorithm (MOEPFA) technique is presented in this study for solving multi-objective power system problems which are minimizing total active and reactive power losses and improving voltage profile while considering the cost of energy losses. This MOEPFA is developed by embedding Firefly Algorithm (FA) features into the conventional EP method. The analysis in this study considered DG with 4 different scenarios. Scenario 1 is the base case or without DG, scenario 2 is for DG with injected active power, scenario 3 is for DG injected with reactive power only and scenario 4 is for DG injected with both active and reactive power. The IEEE 69-bus test system is applied to validate the suggested technique.

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Diagnostics of oil filled cable terminations

2006 , Mohd Rafi Adzman , Muzamir Isa , Baharuddin Ismail , Matti Lehtonen , Petri Hyvonen

Cable termination is one of the important components in the electrical power system. A failure of it can cause a long interruption, costly repair and loss of revenue. An existing oil filled cable termination such as rubber tube and porcelain type of cable termination require an observation and preventive maintenance in order to prevent an enormous electrical system failure in future. One of the defects ot this type of oil filled cable termination is lack of insulation oil inside it. The worst case if it becomes totally empty and at the same time there is no approach taht can help detect it. This paper presents the work carried out to find any possible method that can be used to detect a drying out of oil impregnated paper tape cable terminations. Futhermore, the diagnosis has to be used without destroying the terminations. Two diagnosis methods, infrared (IR) thermography and X-ray imaging are reviewed and the diagnosis result is presented. By comparison of two diagnosis method in this work, the X-ray imaging method is the best approach to observe and detect a drying out of paper tape oil impregnated cable terminations.

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Differential equation fault location algorithm with harmonic effects in power system

2023-06 , Izatti Md. Amin , Mohd Rafi Adzman , Haziah Abdul Hamid , Muhd Hafizi Idris , Melaty binti Amirruddin , Omar Aliman

About 80% of faults in the power system distribution are earth faults. Studies to find effective methods to identify and locate faults in distribution networks are still relevant, in addition to the presence of harmonic signals that distort waves and create deviations in the power system that can cause many problems to the protection relay. This study focuses on a single line-to-ground (SLG) fault location algorithm in a power system distribution network based on fundamental frequency measured using the differential equation method. The developed algorithm considers the presence of harmonics components in the simulation network. In this study, several filters were tested to obtain the lowest fault location error to reduce the effect of harmonic components on the developed fault location algorithm. The network model is simulated using the alternate transients program (ATP)Draw simulation program. Several fault scenarios have been implemented during the simulation, such as fault resistance, fault distance, and fault inception angle. The final results show that the proposed algorithm can estimate the fault distance successfully with an acceptable fault location error. Based on the simulation results, the differential equation continuous wavelet technique (CWT) filter-based algorithm produced an accurate fault location result with a mean average error (MAE) of less than 5%.

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