Muhammad NurHakim Nizam - Academia.edu (original) (raw)

Papers by Muhammad NurHakim Nizam

International Journal of Power Electronics and Drive Systems (IJPEDS)

The lithium-ion (Li-ion) battery has a high demand because of its long cycle, reliability, high e... more The lithium-ion (Li-ion) battery has a high demand because of its long cycle, reliability, high energy density, low toxic, low self-discharge rate, high power density, and high efficiency. However, lithium-ion batteries have sensitivity to over-charge, temperature, and charge discharge currents. The conventional battery charging system takes a very long time to charge which makes the battery temperature high. Therefore, a charger system that can maximize charging capacity, shorten charging time, and extend battery life is needed. In this study, a battery charging system was developed using the constant current–fuzzy (CC-fuzzy) control method. The aim is to get faster charging time and maintain battery life by limiting the battery charging temperature. The proposed charger system is dual mode which can be operated in both buck and boost mode. The experimental result shows that the proposed method is superior compared to the constant current constant voltage (CCCV) method in charging ...

Jurnal Ilmiah Teknik Elektro Komputer dan Informatika, 2021

This paper presents dynamic voltage collapse prediction on an actual power system using support v... more This paper presents dynamic voltage collapse prediction on an actual power system using support vector machines. Dynamic voltage collapse prediction is first determined based on the PTSI calculated from information in dynamic simulation output. Simulations were carried out on a practical 87 bus test system by considering load increase as the contingency. The data collected from the time domain simulation is then used as input to the SVM in which support vector regression is used as a predictor to determine the dynamic voltage collapse indices of the power system. To reduce training time and improve accuracy of the SVM, the Kernel function type and Kernel parameter are considered. To verify the effectiveness of the proposed SVM method, its performance is compared with the multi layer perceptron neural network (MLPNN). Studies show that the SVM gives faster and more accurate results for dynamic voltage collapse prediction compared with the MLPNN.

International Journal of Power Electronics and Drive Systems, 2021

Braking systems in motor vehicles generally use a braking system that utilizes friction. The brak... more Braking systems in motor vehicles generally use a braking system that utilizes friction. The braking performance will decrease caused by using friction rapidly. To overcome this, as an alternative, an electromagnetic braking system can be used by utilizing eddy currents, such as eddy current brakes (ECB). Eddy currents are generated when the rotor pass the magnetic field of the electromagnet. The research aim is to design an ECB system. The performance of the disk design will be determined in this study. The study is about the tendency of the ECB properties. The finite element (FEM) method is used by modeling ECB performance. The experimental results were used to validate the result. The test showed the results of braking using aluminum disk showed the best performance in 12.03 Nm. From these results, the combination of the disks is needed by an appropriate disk design.

World Electric Vehicle Journal, 2021

The increase in electric vehicles needs to be supported by the existence of reliable energy stora... more The increase in electric vehicles needs to be supported by the existence of reliable energy storage devices. The battery, as an energy storage system, has its advantages and disadvantages. The combination of different battery types is chosen since the battery is one of the energy storage systems with mature technology and low life cycle cost. A solution that can be proposed to cover the weakness of each battery is the use of the Dual Battery System (DBS). In this project, a dual battery control system with a combination of Valve Regulated Lead Acid (VRLA) and Lithium Ferro Phosphate (LFP) batteries was developed using the switching method. Battery selection switching is determined by the specification and operational set point of the battery used. The experimental testing was carried out. The result of the research conducted showed that the current sensor accuracy was 83.75% and the voltage sensor accuracy was 94.25% while the current sensor precision value was 64.91% and the voltag...

Applied Sciences, 2020

Highly crystalline “zero-strain” Li4Ti5O12 (LTO) has great potential as an alternative material f... more Highly crystalline “zero-strain” Li4Ti5O12 (LTO) has great potential as an alternative material for the anodes in a lithium ion battery. In this research, highly crystalline LTO with impressive electrochemical characteristics was synthesized via a salt-assisted solid-state reaction using TiO2, LiOH, and various amounts of NaCl as a salt additive. The LTO particles exhibited a cubic spinel structure with homogenous micron-sized particles. The highest initial specific discharge capacity of LTO was 141.04 mAh/g with 4 wt % NaCl addition, which was tested in a full-cell (LTO/LiFePO4) battery. The battery cell showed self-recovery ability during the cycling test at 10 C-rate, which can extend the cycle life of the cell. The salt-assisted process affected the crystallinity of the LTO particles, which has a favorable effect on its electrochemical performance as anodes.

Applied Sciences, 2020

The braking system in a vehicle has the main role of slowing down the speed or stopping the movin... more The braking system in a vehicle has the main role of slowing down the speed or stopping the moving vehicle. Compared to mechanical braking, which utilizes friction, non-contact braking has several advantages, including longer lifetime and less maintenance. One form of non-contact braking systems is the eddy current brake (ECB), an electric braking system that employs eddy currents to operate. This research focuses on the impact of magnetic field sources used in the ECB. In addition, the number of magnetic field sources is also observed. In order to achieve an ECB design that can be easily applied in any types of vehicles, including motorcycles and compact cars, a compact ECB design with an excellent braking torque is required. In this study, a compact design of the ECB is obtained by distributing the required braking torque from the disc brake into multiple electromagnets. Finite element method-based modeling has been performed to study ECB parameters, including the number of coil w...

Energies, 2020

The high throughput and rapid flame-assisted spray pyrolysis method has been adapted to synthesiz... more The high throughput and rapid flame-assisted spray pyrolysis method has been adapted to synthesize cathode materials LiNi0.apCo0.15Al0.035O2 (NCA). This method is considered low cost and simple. By varying the precursor solution concentration and sintering temperature, the optimal condition was established at temperature sintering of 800 °C and precursor solution concentration of 1 M. X-ray diffraction patterns showed the as-prepared NCA particles exhibit a pure well-ordered hexagonal layer structure with high crystallinity. Polyhedral shaped micro-sized particles are confirmed by SEM images. Galvanostic charge–discharge tests were conducted using cylindrical full-cell utilizing artificial graphite as the anode. The highest specific initial discharge capacity measured between 2.7 and 4.3 V is 155 mAh g−1 with capacity retention of 92% after cycled at 0.2 C for 50 cycles. Thus, this method is considered as a satisfying approach for NCA mass production.

Journal of Electrical, Electronic, Information, and Communication Technology, 2020

We fabricated a ZnO nanostructures based TFT on plastic substrate by solution method under low te... more We fabricated a ZnO nanostructures based TFT on plastic substrate by solution method under low temperature. ZnO nanostructures were prepared by zinc nitrate hexahydrate, and hexamethylenetetramine. The device shows hard saturation characteristics and exhibits a high off-resistance. The output characteristics devices also shows current saturation and pinch off behavior, in which the high of current saturation obtained 266 mA at VGS = 40 V and VDS = 42.5 V. The pH response on the electrical properties was also studied. It was found that the threshold voltage shifted from 10.21 V to 13 V as pH solution gradually increased. The Ion/Ioff for as grown TFTs and TFTs with pH response of 10.21 shifted from 1.86 x 105 to 7.03 x 106 at VDS = 20 V. The obtained sensitivity of devices was 1.05 V/pH.

Energies, 2020

The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignor... more The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analyt...

Journal of Electrical Engineering and Technology, 2007

2014 International Conference on Electrical Engineering and Computer Science (ICEECS), 2014

The advantages and disadvantages of slotted brushless DC motor (BLDC) and slotless BLDC make the ... more The advantages and disadvantages of slotted brushless DC motor (BLDC) and slotless BLDC make the user confused when they want to choose BLDC motors. The objective of this research was to describe the characteristic of slotted BLDC and slotless BLDC using 2D finite element method. Result of this research showed that slotted BLDC has higher torque than slotless BLDC. The power produced by slotted and slotless BLDC were almost the same, while the speed of the slotless BLDC was 10 times higher than the speed of slotted BLDC. Slotted BLDC produced more ripple torque than slotless BLDC, thus it made slotted BLDC had higher vibration than slotless BLDC.

2014 International Conference on Electrical Engineering and Computer Science (ICEECS), 2014

ABSTRACT

2014 International Conference on Electrical Engineering and Computer Science (ICEECS), 2014

ABSTRACT

TENCON 2009 - 2009 IEEE Region 10 Conference, 2009

2008 IEEE 2nd International Power and Energy Conference, 2008

Abstract This paper presents the application of support vector machines (SVM) for determining vol... more Abstract This paper presents the application of support vector machines (SVM) for determining voltage unstable areas in an actual power system. The voltage unstable area is first determined based on the power transfer stability index (PTSI) calculated using information obtained from dynamic simulation output. Simulations were carried out on a practical 87 bus test system by considering load increase as the contingency. The data collected from time domain simulations are then used as inputs to the SVM which acts as ...

TENCON 2008 - 2008 IEEE Region 10 Conference, 2008

Abstract This paper presents dynamic voltage collapse prediction on an actual power system using ... more Abstract This paper presents dynamic voltage collapse prediction on an actual power system using support vector machines. Dynamic voltage collapse prediction is first determined based on the PTSI calculated from information in dynamic simulation output. Simulations were carried out on a practical 87 bus test system by considering load increase as the contingency. The data collected from the time domain simulation is then used as input to the SVM in which support vector regression is used as a predictor to determine the ...

2013 Joint International Conference on Rural Information & Communication Technology and Electric-Vehicle Technology (rICT & ICeV-T), 2013

ABSTRACT

Applied Mechanics and Materials, 2014

Urban area is the center of activities. Many people use the vehicle to cover the distance toward ... more Urban area is the center of activities. Many people use the vehicle to cover the distance toward their activities places. In order to support the activities a large number of vehicles are moving in urban areas. Consequently, the consumption of fuel will increase from time to time and oil price has increased due to higher of demands. Thus, a plugin hybrid electric vehicle (PHEV) is proven as one of the best practical applications for transportation in order to reduce fuel consumption. One of the types of PHEV is a series PHEV (SPHEV). SPHEV is the simplest type of PHEV but still having higher efficiency of fuel than an internal combustion engine vehicle. This study was focused to discuss on the ability of SPHEV for covering distance and velocity of the urban drive cycle. Three driving cycles namely new European drive cycle (NEDC), extra urban driving cycle (EUDC), and EPA highway fuel economy cycle (HWFET) were used for the simulation using ADVISOR software to study performance of SP...

International Journal of Power Electronics and Drive Systems (IJPEDS)

The lithium-ion (Li-ion) battery has a high demand because of its long cycle, reliability, high e... more The lithium-ion (Li-ion) battery has a high demand because of its long cycle, reliability, high energy density, low toxic, low self-discharge rate, high power density, and high efficiency. However, lithium-ion batteries have sensitivity to over-charge, temperature, and charge discharge currents. The conventional battery charging system takes a very long time to charge which makes the battery temperature high. Therefore, a charger system that can maximize charging capacity, shorten charging time, and extend battery life is needed. In this study, a battery charging system was developed using the constant current–fuzzy (CC-fuzzy) control method. The aim is to get faster charging time and maintain battery life by limiting the battery charging temperature. The proposed charger system is dual mode which can be operated in both buck and boost mode. The experimental result shows that the proposed method is superior compared to the constant current constant voltage (CCCV) method in charging ...

Jurnal Ilmiah Teknik Elektro Komputer dan Informatika, 2021

This paper presents dynamic voltage collapse prediction on an actual power system using support v... more This paper presents dynamic voltage collapse prediction on an actual power system using support vector machines. Dynamic voltage collapse prediction is first determined based on the PTSI calculated from information in dynamic simulation output. Simulations were carried out on a practical 87 bus test system by considering load increase as the contingency. The data collected from the time domain simulation is then used as input to the SVM in which support vector regression is used as a predictor to determine the dynamic voltage collapse indices of the power system. To reduce training time and improve accuracy of the SVM, the Kernel function type and Kernel parameter are considered. To verify the effectiveness of the proposed SVM method, its performance is compared with the multi layer perceptron neural network (MLPNN). Studies show that the SVM gives faster and more accurate results for dynamic voltage collapse prediction compared with the MLPNN.

International Journal of Power Electronics and Drive Systems, 2021

Braking systems in motor vehicles generally use a braking system that utilizes friction. The brak... more Braking systems in motor vehicles generally use a braking system that utilizes friction. The braking performance will decrease caused by using friction rapidly. To overcome this, as an alternative, an electromagnetic braking system can be used by utilizing eddy currents, such as eddy current brakes (ECB). Eddy currents are generated when the rotor pass the magnetic field of the electromagnet. The research aim is to design an ECB system. The performance of the disk design will be determined in this study. The study is about the tendency of the ECB properties. The finite element (FEM) method is used by modeling ECB performance. The experimental results were used to validate the result. The test showed the results of braking using aluminum disk showed the best performance in 12.03 Nm. From these results, the combination of the disks is needed by an appropriate disk design.

World Electric Vehicle Journal, 2021

The increase in electric vehicles needs to be supported by the existence of reliable energy stora... more The increase in electric vehicles needs to be supported by the existence of reliable energy storage devices. The battery, as an energy storage system, has its advantages and disadvantages. The combination of different battery types is chosen since the battery is one of the energy storage systems with mature technology and low life cycle cost. A solution that can be proposed to cover the weakness of each battery is the use of the Dual Battery System (DBS). In this project, a dual battery control system with a combination of Valve Regulated Lead Acid (VRLA) and Lithium Ferro Phosphate (LFP) batteries was developed using the switching method. Battery selection switching is determined by the specification and operational set point of the battery used. The experimental testing was carried out. The result of the research conducted showed that the current sensor accuracy was 83.75% and the voltage sensor accuracy was 94.25% while the current sensor precision value was 64.91% and the voltag...

Applied Sciences, 2020

Highly crystalline “zero-strain” Li4Ti5O12 (LTO) has great potential as an alternative material f... more Highly crystalline “zero-strain” Li4Ti5O12 (LTO) has great potential as an alternative material for the anodes in a lithium ion battery. In this research, highly crystalline LTO with impressive electrochemical characteristics was synthesized via a salt-assisted solid-state reaction using TiO2, LiOH, and various amounts of NaCl as a salt additive. The LTO particles exhibited a cubic spinel structure with homogenous micron-sized particles. The highest initial specific discharge capacity of LTO was 141.04 mAh/g with 4 wt % NaCl addition, which was tested in a full-cell (LTO/LiFePO4) battery. The battery cell showed self-recovery ability during the cycling test at 10 C-rate, which can extend the cycle life of the cell. The salt-assisted process affected the crystallinity of the LTO particles, which has a favorable effect on its electrochemical performance as anodes.

Applied Sciences, 2020

The braking system in a vehicle has the main role of slowing down the speed or stopping the movin... more The braking system in a vehicle has the main role of slowing down the speed or stopping the moving vehicle. Compared to mechanical braking, which utilizes friction, non-contact braking has several advantages, including longer lifetime and less maintenance. One form of non-contact braking systems is the eddy current brake (ECB), an electric braking system that employs eddy currents to operate. This research focuses on the impact of magnetic field sources used in the ECB. In addition, the number of magnetic field sources is also observed. In order to achieve an ECB design that can be easily applied in any types of vehicles, including motorcycles and compact cars, a compact ECB design with an excellent braking torque is required. In this study, a compact design of the ECB is obtained by distributing the required braking torque from the disc brake into multiple electromagnets. Finite element method-based modeling has been performed to study ECB parameters, including the number of coil w...

Energies, 2020

The high throughput and rapid flame-assisted spray pyrolysis method has been adapted to synthesiz... more The high throughput and rapid flame-assisted spray pyrolysis method has been adapted to synthesize cathode materials LiNi0.apCo0.15Al0.035O2 (NCA). This method is considered low cost and simple. By varying the precursor solution concentration and sintering temperature, the optimal condition was established at temperature sintering of 800 °C and precursor solution concentration of 1 M. X-ray diffraction patterns showed the as-prepared NCA particles exhibit a pure well-ordered hexagonal layer structure with high crystallinity. Polyhedral shaped micro-sized particles are confirmed by SEM images. Galvanostic charge–discharge tests were conducted using cylindrical full-cell utilizing artificial graphite as the anode. The highest specific initial discharge capacity measured between 2.7 and 4.3 V is 155 mAh g−1 with capacity retention of 92% after cycled at 0.2 C for 50 cycles. Thus, this method is considered as a satisfying approach for NCA mass production.

Journal of Electrical, Electronic, Information, and Communication Technology, 2020

We fabricated a ZnO nanostructures based TFT on plastic substrate by solution method under low te... more We fabricated a ZnO nanostructures based TFT on plastic substrate by solution method under low temperature. ZnO nanostructures were prepared by zinc nitrate hexahydrate, and hexamethylenetetramine. The device shows hard saturation characteristics and exhibits a high off-resistance. The output characteristics devices also shows current saturation and pinch off behavior, in which the high of current saturation obtained 266 mA at VGS = 40 V and VDS = 42.5 V. The pH response on the electrical properties was also studied. It was found that the threshold voltage shifted from 10.21 V to 13 V as pH solution gradually increased. The Ion/Ioff for as grown TFTs and TFTs with pH response of 10.21 shifted from 1.86 x 105 to 7.03 x 106 at VDS = 20 V. The obtained sensitivity of devices was 1.05 V/pH.

Energies, 2020

The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignor... more The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analyt...

Journal of Electrical Engineering and Technology, 2007

2014 International Conference on Electrical Engineering and Computer Science (ICEECS), 2014

The advantages and disadvantages of slotted brushless DC motor (BLDC) and slotless BLDC make the ... more The advantages and disadvantages of slotted brushless DC motor (BLDC) and slotless BLDC make the user confused when they want to choose BLDC motors. The objective of this research was to describe the characteristic of slotted BLDC and slotless BLDC using 2D finite element method. Result of this research showed that slotted BLDC has higher torque than slotless BLDC. The power produced by slotted and slotless BLDC were almost the same, while the speed of the slotless BLDC was 10 times higher than the speed of slotted BLDC. Slotted BLDC produced more ripple torque than slotless BLDC, thus it made slotted BLDC had higher vibration than slotless BLDC.

2014 International Conference on Electrical Engineering and Computer Science (ICEECS), 2014

ABSTRACT

2014 International Conference on Electrical Engineering and Computer Science (ICEECS), 2014

ABSTRACT

TENCON 2009 - 2009 IEEE Region 10 Conference, 2009

2008 IEEE 2nd International Power and Energy Conference, 2008

Abstract This paper presents the application of support vector machines (SVM) for determining vol... more Abstract This paper presents the application of support vector machines (SVM) for determining voltage unstable areas in an actual power system. The voltage unstable area is first determined based on the power transfer stability index (PTSI) calculated using information obtained from dynamic simulation output. Simulations were carried out on a practical 87 bus test system by considering load increase as the contingency. The data collected from time domain simulations are then used as inputs to the SVM which acts as ...

TENCON 2008 - 2008 IEEE Region 10 Conference, 2008

Abstract This paper presents dynamic voltage collapse prediction on an actual power system using ... more Abstract This paper presents dynamic voltage collapse prediction on an actual power system using support vector machines. Dynamic voltage collapse prediction is first determined based on the PTSI calculated from information in dynamic simulation output. Simulations were carried out on a practical 87 bus test system by considering load increase as the contingency. The data collected from the time domain simulation is then used as input to the SVM in which support vector regression is used as a predictor to determine the ...

2013 Joint International Conference on Rural Information & Communication Technology and Electric-Vehicle Technology (rICT & ICeV-T), 2013

ABSTRACT

Applied Mechanics and Materials, 2014

Urban area is the center of activities. Many people use the vehicle to cover the distance toward ... more Urban area is the center of activities. Many people use the vehicle to cover the distance toward their activities places. In order to support the activities a large number of vehicles are moving in urban areas. Consequently, the consumption of fuel will increase from time to time and oil price has increased due to higher of demands. Thus, a plugin hybrid electric vehicle (PHEV) is proven as one of the best practical applications for transportation in order to reduce fuel consumption. One of the types of PHEV is a series PHEV (SPHEV). SPHEV is the simplest type of PHEV but still having higher efficiency of fuel than an internal combustion engine vehicle. This study was focused to discuss on the ability of SPHEV for covering distance and velocity of the urban drive cycle. Three driving cycles namely new European drive cycle (NEDC), extra urban driving cycle (EUDC), and EPA highway fuel economy cycle (HWFET) were used for the simulation using ADVISOR software to study performance of SP...