DSpaceCRIS@UNITENhttp://dspace.uniten.edu.my/jspuiThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Fri, 24 May 2019 21:05:49 GMT2019-05-24T21:05:49Z50811- FPGA simulation of AD converter by using Giga Hertz speed data acquisition for partial discharge detectionhttp://dspace.uniten.edu.my/jspui/handle/123456789/5727Title: FPGA simulation of AD converter by using Giga Hertz speed data acquisition for partial discharge detection
Authors: Emilliano; Chakrabarty, C.K.; Basri, A.; Ramasamy, A.K.; Ping, L.C.
Abstract: Currently, FPGA (Field Programmable Gate Array) technology is being widely used for accelerator control owing to its fast digital processing capability. This paper is purely a model to determine the design circuit to implement Partial Discharge (PD) detection in FPGA technology. The research shall involve ISE Simulator version 9.2i (Xilinx) and Very high integrated circuit Hardware Description Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA) for the detection and counting of partial discharge signals in underground cable. The impulse signals at the input data have very fast rise time in the range of 1 ns to 2 ns.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/57272010-01-01T00:00:00Z
- Study on P-V Curve and V-Q curve of an unbalanced three- phase system with different static loadshttp://dspace.uniten.edu.my/jspui/handle/123456789/7340Title: Study on P-V Curve and V-Q curve of an unbalanced three- phase system with different static loads
Authors: Ramasamy, A.K.; Verayiah, R.; Abidin, I.Z.; Gunalan, S.; Perumal, P.
Abstract: P-V curve and V-Q curve (often term as Q-V curve) are widely used for planning and operation studies. The P-V curve and V-Q curve of an unbalanced three-phase system, unlike the balanced three-phase system, may not have similar loading margin (LM) and reactive power margin (RPM) on each phase. Therefore, DIgSILENT Programming Language (DPL) has been used to study the maximum loading point (MLP), critical point (CP), and also minimum reactive power point (MRPP) on each phase of an unbalanced three-phase system with different static loads. The tracing direction of P-V curve of each phase and the LM and RPM of each phase obtained from the P-V curve and V-Q curve for different static loads are also discussed. On top of that, continuation power flow (CPF) has become a common method to study the MLP. Hence, a simple 2-bus balanced three-phase system is used to validate the result obtained from the DIgSILENT with CPF method. © 2016, Wydawnictwo SIGMA - N O T Sp. z o.o. All rights reserved.
Fri, 01 Jan 2016 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73402016-01-01T00:00:00Z
- Comparison on microstrip patch antenna modules and rectifier modules for rf energy harvestinghttp://dspace.uniten.edu.my/jspui/handle/123456789/7336Title: Comparison on microstrip patch antenna modules and rectifier modules for rf energy harvesting
Authors: Sangaran, M.; Ramasamy, A.; Din, N.M.; Devi, K.K.A.
Abstract: Electromagnetic energy harvesting holds a promising future as an alternative energy in order to power low power devices. RF energy harvesting systems has been carried out by many researches and efforts have been put into converting RF into usable DC. This paper is a comprehensive review paper which covers the antenna modules and rectifier modules which are being utilized in RF energy harvesting systems over the years. Both the antenna modules and rectifier modules are put into comparison and critically analysed. From the comparisons made, the gaps and challenges are further discussed in detail. © 2006-2016 Asian Research Publishing Network (ARPN).
Fri, 01 Jan 2016 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73362016-01-01T00:00:00Z
- Comparison of the effect of filter designs on the total harmonic distortion in three-phase stand-alone photovoltaic systemshttp://dspace.uniten.edu.my/jspui/handle/123456789/7342Title: Comparison of the effect of filter designs on the total harmonic distortion in three-phase stand-alone photovoltaic systems
Authors: Kean, Y.W.; Yong, P.S.; Ramasamy, A.; Ramachandaramurthy, V.K.
Abstract: The world has turned their attention to renewable energy with the increasing demand of power supply and the limited source of fossil fuel. In Malaysia, solar PV energy is growing steadily as the sunlight is easily available throughout the year. As more solar PV system being installed, stand-alone operation is being looked into to bring solar PV to rural areas. However, in stand-alone operations there is no voltage support from the grid which will lead to harmonic problems. Passive filter is one of the methods used to mitigate the harmonic issues in a stand-alone system. This paper focuses on the design of passive filters and the effects of the filter on the total harmonic mitigation in a 8kW three-phase stand-alone PV system are compared. The design of the proposed filters is validated by simulation results in PSCAD software. The simulation results show that the double tuned filter design is able to meet the THD and individual harmonic limit standards better as compared to the single tuned filter and LC filter design. © 2006-2015 Asian Research Publishing Network (ARPN).
Thu, 01 Jan 2015 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73422015-01-01T00:00:00Z
- MR damper controllers for vehicle airbag replacementhttp://dspace.uniten.edu.my/jspui/handle/123456789/7338Title: MR damper controllers for vehicle airbag replacement
Authors: Dhanaletchmi, N.; Nagi, F.H.; Ramasamy, A.K.
Abstract: Vehicle crashes continues to occur despite all the human efforts to prevent them resulting in injuries and loss of lives. The implementation of air bags has been shown to offer passenger safety in a collision. However, premature deployment of air bag has resulted in fatalities and injuries to drivers and front seat passengers. In this study, a Magnetorheological (MR) damper is used as a replacement of air bag in vehicles to serve as a protective system. MR damper is a smart damping device which can be programmed to dynamically absorb shocks and high impact force when used in application such as passenger cars. In this paper, the implementation of MR damper in reducing the impact force on driver during frontal car crash is studied through MATLAB simulation. The current air bag model in MATLAB has been replaced with the designed MR damper to study the impact force on the driver. In this paper two control techniques; a conventional Proportional Integral and Derivative (PID) and Fuzzy Logic Control (FLC) controllers are proposed for MR damper current control. The performances of the controllers were analysed based on efficiency to minimize Fd, damping force of MR damper system during the crash de-acceleration. Simulation results proved that Fuzzy based MR damper system yields better results compared to PID based MR damper system. © 2006-2016 Asian Research Publishing Network (ARPN).
Fri, 01 Jan 2016 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73382016-01-01T00:00:00Z
- Identification of electrical appliances using non-intrusive magnetic field and Probabilistic Neural Network (PNN)http://dspace.uniten.edu.my/jspui/handle/123456789/7343Title: Identification of electrical appliances using non-intrusive magnetic field and Probabilistic Neural Network (PNN)
Authors: Mohd Rosdi, N.A.; Nordin, F.H.; Ramasamy, A.K.
Abstract: The electricity waste is severe especially in large organizational buildings where the use of air conditioners, fridges and electrical motors are rampant. Due to lack of energy saving consciousness, users may not switch off this equipment after use. Thus, it would be an advantage if there exist a system that will be able to identify the appliances from one place without the residence having to go and check the state of the appliance or without having to place various sensors intrusively. Since most electrical appliances emit magnetic fields, the paper proposes to use non-intrusive magnetic field signature waveforms to identify the type of appliance used. The magnetic field emitted by table fan, blender and hairdryer are chosen for this purpose. The magnetic field from these three appliances are collected from four different measurement distances i.e. (i) 0cm (ii) 10cm (iii) 30cm and (iv) 60cm. The features of the magnetic field are then extracted and trained offline using the Probabilistic Neural Network (PNN). Once trained, the PNN shows that it is able to successfully identify the appliances regardless of the measurement distance. © 2014 IEEE.
Wed, 01 Jan 2014 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73432014-01-01T00:00:00Z
- Efficient illumination design and energy saving through occupancy control for buildinghttp://dspace.uniten.edu.my/jspui/handle/123456789/7350Title: Efficient illumination design and energy saving through occupancy control for building
Authors: Lakshmanan, R.; Ramasamy, A.K.; Ahmed, S.K.; Sinnadurai, R.
Abstract: In any nation, energy is the fuel for its economic development. Realizing the utmost importance of energy, enormous efforts have to be taken in order to secure the energy availability of a nation. Therefore, it is necessary to increase the efficiency of electric energy usage and make use of the renewable energy sources in order to extend the availability of these fuel resources. This paper focuses on the efficient illumination design and occupancy of the main building of Asia Pacific University of Technology & Innovation (APUTI). A detailed load and energy audit was done for APUTI main building. For efficient illumination design the existing lighting design was reviewed and the potential energy saving by delamping the lights were determined and validated with actual photometric measurements. The energy saving through occupancy control was also determined. © 2013 IEEE.
Tue, 01 Jan 2013 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73502013-01-01T00:00:00Z
- DSP based fuzzy and conventional overcurrent relay controller comparisonshttp://dspace.uniten.edu.my/jspui/handle/123456789/7347Title: DSP based fuzzy and conventional overcurrent relay controller comparisons
Authors: Goh, Y.L.; Ramasamy, A.K.; Nagi, F.H.; Zainul Abidin, A.A.
Abstract: Fuzzy logic control uses linguistic approach to solve complicated rules and ambiguous systems. This control strategy can be used to improve the overall performance of an overcurrent relay for power system protection compared to conventional relay. It is essential for a relay to work efficiently to trip the circuit breakers in the presence of faults and at the same time proficient to coordinate well with the networks to avoid mal-operation. There are two different types of fuzzy logic control strategies proposed for the relay, the Fuzzy Logic Controller (FLC) and Fuzzy Bang-Bang Controller (FBBC). The FBBC is the same as the conventional FLC except that the defuzzification method uses largest of maxima (LOM). Comparisons between the fuzzy controllers and conventional relay are based on IEC 255-3 standard. These relays are implemented on a DSP TMS320F2812 and their performance is evaluated which is based on operation time, DSP's execution time and grading margin. The results obtained show a significant performance improvement compared to conventional relay. © 2013 Elsevier Ltd. All rights reserved.
Tue, 01 Jan 2013 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73472013-01-01T00:00:00Z
- VHDL implementation for measurement of the distance test distribution pattern of the Tri-Axial magnetic probe for the PD detection circuit system by using 3 GHz ADC and FPGAhttp://dspace.uniten.edu.my/jspui/handle/123456789/7352Title: VHDL implementation for measurement of the distance test distribution pattern of the Tri-Axial magnetic probe for the PD detection circuit system by using 3 GHz ADC and FPGA
Authors: Emilliano; Chakrabarty, C.K.; Ghani, A.B.A.; Ramasamy, A.K.
Abstract: This paper is purely a model to implement Partial Discharge (PD) detection in FPGA technology and then implement the VHDL modeled in FPGA technology for measurement of the distance test distribution pattern of the Tri-Axial magnetic probe using 3GHz ADC (ADC083000RB-Reference Board) and impulse generator. Partial discharge (PD) is a well known phenomenon that causes insulation degradation in cross linked polyethylene (XLPE) power cable and ultimately it will cause insulation failure. The research shall involve ISE Simulator version 10.1i (Xilinx) and ISE Xilinx Synthesized Technology (XST) using Very high integrated circuit Hardware Description Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA-Xilinx Virtex 5 ML501 Board) for the detection and counting of partial discharge signals in high voltage underground cable. The impulse signals at the input data have very fast rise time in the field can have a bandwith of about 200 - 600 MHz. The output signals of the combination 4 blocks (peak detector block, 64 bit BCD counter with reset block, reset automatic block and 64 bit BCD counter) is processed using reset automatic block and 64 bit latch block for keep output data in LCD to constant when the 64 bit BCD counter block is reset and return to zero again until update new data again. The combination of all blocks of PD detection circuit system is tested by using Xilinx ISE simulator and implemented by ISE Xilinx Synthesized Technology and Xilinx ISE Implement Design. The distance resolution measurement of magnetic field is shown in this paper. © 2011 IEEE.
Sun, 01 Jan 2012 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73522012-01-01T00:00:00Z
- Partial discharge detection system for counting PD signals in high voltage underground cable by using FPGA technologyhttp://dspace.uniten.edu.my/jspui/handle/123456789/7358Title: Partial discharge detection system for counting PD signals in high voltage underground cable by using FPGA technology
Authors: Emilliano; Chakrabarty, C.K.; Ramasamy, A.K.; Ghani, A.B.A.
Abstract: Currently, FPGA (Field Programmable Gate Array) technology is being widely used for signal processing and control owing to its fast digital processing capability. We have recently developed successfully a high-speed data acquisition system that combines a commercial FPGA board (ML405) with the high speed ADC in ADC 083000RB that has 8 bit pairs LVDS in resolution, sampling rate of 3 GS/s and bandwidth of 3 GHz for counting very high speed transient signals. The programming is in VHDL. This system enables direct measurement and counting of transient signals at 1-10 ns pulse width at a sampling frequency 3 GHz. The partial discharge (PD) signals in this work are simulated by using Pico Pulse generator. All the counting is performed in the FPGA without the use of oscilloscope. The count rates are displayed in the LCD monitor of the FPGA hence rendering it to be highly mobile. © 2011 Institute of Electrical Power.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73582010-01-01T00:00:00Z
- Numerical relay for overcurrent protection using TMS320F2812http://dspace.uniten.edu.my/jspui/handle/123456789/7359Title: Numerical relay for overcurrent protection using TMS320F2812
Authors: Goh, Y.L.; Ramasamy, A.K.; Nagi, F.H.; Abidin, A.A.Z.
Abstract: Overcurrent protection is a very important element in power systems. This protection is essential in order to minimize disturbances caused by any failure in the system and to ensure continuous power delivery. Overcurrent relays are one of the devices used to achieve these purposes. The overcurrent relays initiate the corrective mechanism to determine the operation time of the relay. Thus, the overcurrent relays must have high reliability and accuracy to detect any fault currents present and determine the operation time. The entire system will be tremendously affected if the relays fail to trip or cause mal-tripping. An overcurrent relay is implemented on a high speed and high performance digital signal processor (DSP). The simulation was carried out using MATLAB/Simulink. Then, the relay was implemented on TMS320F2812 based on two different methods. In the first method, the relay simulation model from MATLAB/Simulink is downloaded into the DSP whereas in the second method, code in C is directly written on the DSP to represent the relay. The relay performance was compared with the IEC 255-3 standard and the outcomes obtained are encouraging.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73592010-01-01T00:00:00Z
- Digital signal processor based over-current relay using fuzzy logic controllerhttp://dspace.uniten.edu.my/jspui/handle/123456789/7355Title: Digital signal processor based over-current relay using fuzzy logic controller
Authors: Goh, Y.L.; Ramasamy, A.K.; Nagi, F.H.; Abidin, A.A.Z.
Abstract: Protection and control are important aspects in real-time applications. Protection and control are required to ensure that safety and security of the system is achieved. In a power system, protection relays are used to minimize the disturbances caused by failure in the system to ensure continuous power delivery. Protection relays, such as over-current relays, are required to improve their reliability, since the power system is seriously affected by the faults either caused by internal or external sources. The relay must work efficiently to trip the circuit breakers if there are faults present. In this article, an over-current relay is designed based on fuzzy logic control to improve the overall performance of the relay. The over-current relay is implemented on a digital signal processor (TMS320F2812, Texas Instruments, Dallas, Texas, USA). The relay performance was compared with the IEC standard, and the results obtained are promising. Copyright © Taylor & Francis Group, LLC.
Sat, 01 Jan 2011 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73552011-01-01T00:00:00Z
- DSP based overcurrent relay using fuzzy bang-bang controllerhttp://dspace.uniten.edu.my/jspui/handle/123456789/7354Title: DSP based overcurrent relay using fuzzy bang-bang controller
Authors: Goh, Y.L.; Ramasamy, A.K.; Nagi, F.H.; Abidin, A.A.Z.
Abstract: Overcurrent relays are very important protection component that require high reliability to maintain high security in power systems. With the new numerical relay technology using digital signal processor (DSP), it is possible to improve the performance of the relay significantly. However, application of DSP in numerical overcurrent relays is limited especially in coordination among the group of relays. The relay must work proficiently to coordinate with the networks in order to avoid mal-operation. Therefore, in this paper, an implementation of overcurrent relay with improved coordination on a DSP, TMS320F2812 is described. The fuzzy bang-bang controller is used as the control strategy for the relay to provide efficient control for overcurrent protection. The performance evaluation of the proposed system is based on steady state analysis, transient state analysis, coordination and lastly the execution time of the DSP. The results obtained using this new proposed controller is very promising. © 2011 Elsevier Ltd. All rights reserved.
Sat, 01 Jan 2011 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73542011-01-01T00:00:00Z
- MATLAB and VHDL model of real time partial discharge detection using FPGA technologyhttp://dspace.uniten.edu.my/jspui/handle/123456789/7353Title: MATLAB and VHDL model of real time partial discharge detection using FPGA technology
Authors: Emilliano; Chakrabarty, C.K.; Ramasamy, A.K.; Ghani, A.B.A.
Abstract: This research involves evaluating the use of FPGA for the detection and counting of partial discharge (PD) signals in underground cables (XLPE cables). PD detection model was designed one using MATLAB and another using VHDL. The pulse signal from the cable was processed and counted using peak detector and FPGA technology. The peak detector placed inside the VHDL program when the program of PD detection model was designed using VHDL program. Then, the model designed was used for testing and validation. Both models are able detect the PD signals and the results obtained are similar. © 2011 IEEE.
Sat, 01 Jan 2011 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73532011-01-01T00:00:00Z
- VHDL simulation of reset automatic block, 64 bit latch block, and test complete blocks for PD detection circuit system using FPGAhttp://dspace.uniten.edu.my/jspui/handle/123456789/7363Title: VHDL simulation of reset automatic block, 64 bit latch block, and test complete blocks for PD detection circuit system using FPGA
Authors: Emilliano; Chakrabarty, C.K.; Ghani, A.B.A.; Ramasamy, A.K.
Abstract: This paper is purely a model to determine the design circuit to implement Partial Discharge (PD) detection in FPGA technology. The research shall involve ISE Simulator version 10.1i (Xilinx) and ISE Xilinx Synthesized Technology (XST) using Very high integrated circuit Hardware Description Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA) for the detection and counting of partial discharge signals in high voltage underground cable. The impulse signals at the input data have very fast rise time in the range of 1 ns to 2 ns. The output signals of peak detector block, 64 bit BCD counter with reset block and reset automatic block is processed using reset automatic block and 64 bit latch block for keep output data in LCD to constant when the 64 bit BCD counter block is reset and return to zero again until update new data again. The combination of all blocks of PD detection circuit system is tested by using ISE simulator. In the next stage, this method will be implemented on a lab simulation scale for testing and validation. © 2010 IEEE.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73632010-01-01T00:00:00Z
- Online partial discharge counting system using microcontroller PIC 16F877A and FPGA technologyhttp://dspace.uniten.edu.my/jspui/handle/123456789/7360Title: Online partial discharge counting system using microcontroller PIC 16F877A and FPGA technology
Authors: Emilliano; Chakrabarty, C.K.; Ghani, A.B.A.; Ramasamy, A.K.
Abstract: This paper is purely a design circuit to implement Partial Discharge (PD) detection in FPGA technology using Xilinx ML405 board (Virtex 4) and real time ADC in microcontroller PIC 16F877 A. The research involve ISE Simulator version 10.1i (Xilinx) and ISE Xilinx Synthesized Technology (XST) using Very high integrated circuit Hardware Description Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA) for the detection and counting of partial discharge signals in high voltage underground cable. The research also involve PCWH CCS C Compiler using C programming to run real time ADC in microcontroller PIC 16F877A. The impulse of PD signals is simulated by impulse generator in the lab simulation. The input data (PD signals) in high voltage underground cable have very fast rise time in the range of 1 ns to 2 ns in the real system. The speed clock of the real time ADC in microcontroller PIC is 20 MHz. This paper shows analysis data of ability of real time ADC in microcontroller PIC to measurement, detect and counting PD signal using FPGA technology. The combination of all blocks of PD detection circuit system is tested by using ISE Xilinx Synthesis Technology (XST) and ISE implementation. In the next stage, this method will be implemented on a next lab simulation scale using real PD signals that is detected by 3D magnetic probe sensor in real underground cable in laboratory for testing and validation before test in the real situation. ©2010 lEEE.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73602010-01-01T00:00:00Z
- Impact of static load on voltage stability of an unbalanced distribution systemhttp://dspace.uniten.edu.my/jspui/handle/123456789/7361Title: Impact of static load on voltage stability of an unbalanced distribution system
Authors: Gunalan, S.; Ramasamy, A.K.; Verayiah, R.
Abstract: Static load which is known for three different characteristics i.e. constant power, constant current and constant impedance shows a different voltage profile because both of their real power and reactive power vary differently as the voltage varies except for constant power. This paper will analyze the impact of each load characteristic individually and also as combination on voltage stability of an IEEE 34 Bus Distribution System by increasing the load demand, and also transient analysis i.e. creating a single phase-to-ground fault i.e. on phase a and balanced three phase fault. The most suitable load to study the voltage stability is also proposed. It was found that, with constant power loads, the reactive power demand increases significantly when load real power and reactive power increases by 25%. Constant current loads and combination loads, on the other hand, the reactive power demand increases but only slightly and the demand is even lesser when with constant impedance loads. However, as the load real power and reactive power increases by 50%, constant power loads causes voltage collapse whilst constant current loads and combination loads turn out to be the next in the order followed by constant impedance loads. In transient analysis, during the single phase fault, with combination loads, phase b voltage increases drastically but only small increment observed in phase c voltage. During the three phase fault, phase b voltage is slightly higher than phase c voltage followed by phase a voltage. As comparison to combination loads, constant power loads causes lesser three phase voltages. After the fault was cleared, a smooth voltage waveform obtained in the period of retaining back to the same pre-fault voltage, however, distortions in the voltage recovering waveform seen when dynamic load included in the system. Constant power load is found to be the suitable load to study the voltage stability. ©2010 IEEE.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73612010-01-01T00:00:00Z
- Modelling of overcurrent relay using digital signal processorhttp://dspace.uniten.edu.my/jspui/handle/123456789/7362Title: Modelling of overcurrent relay using digital signal processor
Authors: Goh, Y.L.; Ramasamy, A.K.; Abidin, A.A.Z.; Nagi, F.H.
Abstract: Protective relays are used to detect any abnormalities in a power system and isolate the faulty section of the system in the shortest time, in order to minimize disturbances caused by failure in the system to ensure continuous power delivery. Protective relays for overcurrent protection are the most widely used relays in a power system. The implementation of overcurrent relay on digital signal processor (DSP) proficient to mitigate problems such as lack of memory capacity, lower speed and functionality, compared to conventional approach using microprocessor. The modelling of overcurrent relay for inverse definite minimum time (IDMT) type using DSP board TMS320F2812 will be discussed in the paper. Simulation results of the overcurrent relay from MATLAB/ Simulink and execution on TMS320F2812 will be presented. ©2010 IEEE.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73622010-01-01T00:00:00Z
- Overcurrent time delay determination using gain scheduled PID controllershttp://dspace.uniten.edu.my/jspui/handle/123456789/7368Title: Overcurrent time delay determination using gain scheduled PID controllers
Authors: Zainul, A.A.; Ramasamy, A.; Abidin, I.Z.; Nagi, F.H.
Abstract: The inverse time overcurrent relay operation is based upon the current setpoint and also the time multiplier setting. Depending on the ratio of the value of the current and the setpoint current together with the value of the time multiplier setting, the amount of time delay for the trip command is determined using the inverse time characteristics. This would mean that the relay is not of the adaptive type and would possibly give a maltripping. This paper uses the concept of PID controller to determine the time delay for the overcurrent relay. ©2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73682009-01-01T00:00:00Z
- An apporach for analyzing queuing systems using Markov chain Monte Carlo methods: A traffic flow case studyhttp://dspace.uniten.edu.my/jspui/handle/123456789/7367Title: An apporach for analyzing queuing systems using Markov chain Monte Carlo methods: A traffic flow case study
Authors: Wong, X.C.; Ahmed, S.K.; Zulkifli, F.; Ramasamy, A.K.
Abstract: In our urban community, having to wait In line Is a dally nuisance as precious time Is wasted. One simple example Is traffic congestion on roads. Reduction of these congestions will not only minimize time wastage but also lead to a healthier life. For this reason, various approaches have been taken to mitigate this problem. In this paper, a simulation approach is proposed to model and investigate the behavior of traffic flow on roads. This is due to the difficulty in obtaining exact solutions based on probability theory and queuing systems even for moderately complex systems. In this paper, the simulation technique used is based on the Markov Chain Monte Carlo technique. It is noticed that the result obtained shows that traffic behavior can be modeled accurately. Thus, this simple approach can be extended to other similar systems such as computer networks, communication systems, etc. ©2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73672009-01-01T00:00:00Z
- FPGA simulation of AD converter by using Giga Hertz speed data acquisition for partial discharge detectionhttp://dspace.uniten.edu.my/jspui/handle/123456789/7364Title: FPGA simulation of AD converter by using Giga Hertz speed data acquisition for partial discharge detection
Authors: Emilliano; Chakrabarty, C.K.; Basri, A.; Ramasamy, A.K.; Ping, L.C.
Abstract: Currently, FPGA (Field Programmable Gate Array) technology is being widely used for accelerator control owing to its fast digital processing capability. This paper is purely a model to determine the design circuit to implement Partial Discharge (PD) detection in FPGA technology. The research shall involve ISE Simulator version 9.2i (Xilinx) and Very high integrated circuit Hardware Description Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA) for the detection and counting of partial discharge signals in underground cable. The impulse signals at the input data have very fast rise time in the range of 1 ns to 2 ns.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73642010-01-01T00:00:00Z
- Fundamental frequency model of a dynamic voltage restorerhttp://dspace.uniten.edu.my/jspui/handle/123456789/7377Title: Fundamental frequency model of a dynamic voltage restorer
Authors: Iyer, R.K.; Ramasamy, A.K.; Ramachandaramuthy, V.K.; Murkerjee, R.N.
Abstract: This paper encompasses the fundamental frequency model of a Dynamic Voltage Restorer (DVR) based on a voltage source converter (VSC) with IGBT switches. Using basic circuit analysis and Matlab simulation program, a simple single-phase circuit model is obtained to assist in analyzing the component parameters of the circuit with various load power factor and voltage sag with phase jump. The fundamental frequency model is obtained assuming negligible effect of harmonics and balanced three-phase voltage sag. This model would introduce a relationship between the desired injected voltage vector and the actual injection voltage vector. This relationship is defined as the correction factor, K. This factor will provide the compensation necessary to produce an accurate injected voltage vector taking into account the voltage drops and phase shifts caused by the filter elements and transformer connected between the voltage source converter (VSC) and the load. © 2005 IEEE.
Sat, 01 Jan 2005 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73772005-01-01T00:00:00Z
- Under voltage load shedding (UVLS) study for 746 test bus systemhttp://dspace.uniten.edu.my/jspui/handle/123456789/7370Title: Under voltage load shedding (UVLS) study for 746 test bus system
Authors: Verayiah, R.; Ramasamy, A.; Abidin, H.I.Z.; Musirin, I.
Abstract: Voltage collapse phenomenon is known to be complex and localized in nature but with a widespread effect. The ultimate effect of voltage collapse would be total system collapse which would incur high losses to utility companies. Thus, on- line monitoring of power system stability has become a vital factor for electric utility companies. One of the methods to avoid voltage collapse is to perform Under Voltage Load Shedding (UVLS). Fast Voltage Stability Index (FVSI) index is proven to be a good indicator for voltage stability in a system. This paper analyzes the correlation between FVSI and the placement of UVLS relays for a 746 test bus system. It is found from the simulations results that FVSI index can be used as an indicator for the placement of UVLS relays in a power system network. ©2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73702009-01-01T00:00:00Z
- Traffic flow simulation at an unsignalized t-junction using monte carlo markov chainshttp://dspace.uniten.edu.my/jspui/handle/123456789/7371Title: Traffic flow simulation at an unsignalized t-junction using monte carlo markov chains
Authors: Ci, W.X.; Ahmed, S.K.; Zulkifli, F.; Ramasamy, A.K.
Abstract: Congested traffic conditions are a daily nuisance of modern life. Reduction of these congestions will lead to a less stressful and healthier commute. Before mitigating solutions can be obtained, the problem needs to be understood and analyzed. Exact solutions based on probability theory and queuing systems are difficult to obtain for even moderately complex systems. Further for complex systems, insight into system behaviour is not very clear. In this paper, a simulation technique based on the Monte Carlo Markov Chain is applied to an unsignalized T-junction. It is noticed that a "small" number of simulations are sufficient to understand the behavior of the system. This simple yet powerful method offers several options and hence, is very appealing. The method can be easily extended to other types of systems as well.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73712009-01-01T00:00:00Z
- Control of Dynamic Voltage Restorer using TMS320F2812http://dspace.uniten.edu.my/jspui/handle/123456789/7375Title: Control of Dynamic Voltage Restorer using TMS320F2812
Authors: Ramasamy, A.; Ramachandaramurthy, V.K.; Iyer, R.K.; Liew, Z.L.
Abstract: Dynamic Voltage Restorer (DVR) is a custom power device that is used to compensate voltage sag. The DVR generally consists of voltage source inverter (VSI), injection transformers, passive filters and energy storage (battery). The efficiency of the DVR depends on the efficiency of the control technique involved in switching the inverters. The inverters are switched using Space Vector Pulse Width Modulation pulses (SVPWM) to maximize the usage of DC link voltage. The control strategy that is used to generate the pulses will be illustrated in this paper. The flow chart of the program and the modules involved in the implementation of the control algorithm using DSP board TMS320F2812 will be described in detail. The implementation of the control using TMS320F2812 is tested using a 3kVA lab prototype and the results are presented.
Mon, 01 Jan 2007 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73752007-01-01T00:00:00Z
- Automatic online signature verification: A prototype using neural networkshttp://dspace.uniten.edu.my/jspui/handle/123456789/7369Title: Automatic online signature verification: A prototype using neural networks
Authors: Ahmed, S.K.; Ramasamy, A.K.; Khairuddin, A.S.Mohd.; Omar, J.
Abstract: Signature verification is the process used to recognize an individual's handwritten signature to prevent fraud. In this paper pressure at the pen-tip together with the x, and y coordinates of the signature are measured and features extracted from these are used to verify the signature. A pressure pad was used to obtain signature samples. A signature verification system using SOM neural network was designed in MATLAB to verify the signatures. Results obtained using a prototype system are encouraging. The attractive features of this system are its low cost, low intrusion, good performance and use of an acceptable and natural biometric (the signature). © 2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73692009-01-01T00:00:00Z
- Dynamic voltage restorer for voltage sag compensationhttp://dspace.uniten.edu.my/jspui/handle/123456789/7376Title: Dynamic voltage restorer for voltage sag compensation
Authors: Ramasamy, A.K.; Iyer, R.K.; Ramachandaramuthy, V.K.; Mukerjee, R.N.
Abstract: The Dynamic Voltage Restorer (DVR) is a power electronic device that is used to inject 3-phase voltage in series and in synchronism with the distribution feeder voltages in order to compensate for voltage sag. In this paper the operation of a DVR is presented. The power circuit of a DVR together with the control techniques used for compensation is explained. The operation of the Software Phase Locked Loop (SPLL) and its stability are analyzed. The DVR control system is described and verified using simulation. The control algorithm implemented using DSP was tested using generated input voltage signals and the results are also presented. The micro-cycle effect of battery current for balanced and unbalanced sag is also investigated. © 2005 IEEE.
Sat, 01 Jan 2005 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73762005-01-01T00:00:00Z
- Dynamic voltage restorer lab prototypehttp://dspace.uniten.edu.my/jspui/handle/123456789/7374Title: Dynamic voltage restorer lab prototype
Authors: Ramasamy, A.K.; Ramachandaramurthy, V.; Iyer, R.K.
Abstract: Voltage sag according to the IEEE standard is a momentary decrease (10% -90%) in the root mean square (rms) voltage magnitude where the duration is longer than half a cycle and less that one minute [1]. The common causes of voltage sag are faults or short circuit in the system, starting of large loads and faulty wiring. Dynamic Voltage Restorer (DVR) is a custom power device that is used to compensate voltage sag. The DVR generally consists of voltage source converter (VSC), injection transformers, filters and energy storage (battery). The control strategy and the implementation of the control strategy using DSP board TMS320F2812 will be briefly discussed in the paper. Simulation results of the control strategy for voltage sag and swell will be presented. This paper will focus on the design and the commissioning of a 3kVa DVR lab prototype. Experimental results of a working DVR lab prototype will be presented. ©2008 IEEE.
Tue, 01 Jan 2008 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73742008-01-01T00:00:00Z
- Comparison of the effect of filter designs on the total harmonic distortion in three-phase stand-alone photovoltaic systemshttp://dspace.uniten.edu.my/jspui/handle/123456789/7747Title: Comparison of the effect of filter designs on the total harmonic distortion in three-phase stand-alone photovoltaic systems
Authors: Kean, Y.W.; Yong, P.S.; Ramasamy, A.; Ramachandaramurthy, V.K.
Abstract: The world has turned their attention to renewable energy with the increasing demand of power supply and the limited source of fossil fuel. In Malaysia, solar PV energy is growing steadily as the sunlight is easily available throughout the year. As more solar PV system being installed, stand-alone operation is being looked into to bring solar PV to rural areas. However, in stand-alone operations there is no voltage support from the grid which will lead to harmonic problems. Passive filter is one of the methods used to mitigate the harmonic issues in a stand-alone system. This paper focuses on the design of passive filters and the effects of the filter on the total harmonic mitigation in a 8kW three-phase stand-alone PV system are compared. The design of the proposed filters is validated by simulation results in PSCAD software. The simulation results show that the double tuned filter design is able to meet the THD and individual harmonic limit standards better as compared to the single tuned filter and LC filter design. © 2006-2015 Asian Research Publishing Network (ARPN).
Thu, 01 Jan 2015 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/77472015-01-01T00:00:00Z
- Dynamic voltage restorer lab prototypehttp://dspace.uniten.edu.my/jspui/handle/123456789/7794Title: Dynamic voltage restorer lab prototype
Authors: Ramasamy, A.K.; Ramachandaramurthy, V.; Iyer, R.K.
Abstract: Voltage sag according to the IEEE standard is a momentary decrease (10% -90%) in the root mean square (rms) voltage magnitude where the duration is longer than half a cycle and less that one minute [1]. The common causes of voltage sag are faults or short circuit in the system, starting of large loads and faulty wiring. Dynamic Voltage Restorer (DVR) is a custom power device that is used to compensate voltage sag. The DVR generally consists of voltage source converter (VSC), injection transformers, filters and energy storage (battery). The control strategy and the implementation of the control strategy using DSP board TMS320F2812 will be briefly discussed in the paper. Simulation results of the control strategy for voltage sag and swell will be presented. This paper will focus on the design and the commissioning of a 3kVa DVR lab prototype. Experimental results of a working DVR lab prototype will be presented. ©2008 IEEE.
Tue, 01 Jan 2008 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/77942008-01-01T00:00:00Z
- Control of Dynamic Voltage Restorer using TMS320F2812http://dspace.uniten.edu.my/jspui/handle/123456789/7795Title: Control of Dynamic Voltage Restorer using TMS320F2812
Authors: Ramasamy, A.; Ramachandaramurthy, V.K.; Iyer, R.K.; Liew, Z.L.
Abstract: Dynamic Voltage Restorer (DVR) is a custom power device that is used to compensate voltage sag. The DVR generally consists of voltage source inverter (VSI), injection transformers, passive filters and energy storage (battery). The efficiency of the DVR depends on the efficiency of the control technique involved in switching the inverters. The inverters are switched using Space Vector Pulse Width Modulation pulses (SVPWM) to maximize the usage of DC link voltage. The control strategy that is used to generate the pulses will be illustrated in this paper. The flow chart of the program and the modules involved in the implementation of the control algorithm using DSP board TMS320F2812 will be described in detail. The implementation of the control using TMS320F2812 is tested using a 3kVA lab prototype and the results are presented.
Mon, 01 Jan 2007 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/77952007-01-01T00:00:00Z
- Small signal stability analysis of grid connected photovoltaichttp://dspace.uniten.edu.my/jspui/handle/123456789/7331Title: Small signal stability analysis of grid connected photovoltaic
Authors: Aun, S.L.Z.; Marsadek, M.B.; Ramasamy, A.K.
Abstract: This paper primarily focuses on the small signal stability analysis of a power system integrated with solar photovoltaics (PV). The test system used in this study is the IEEE 39-bus. The small signal stability of the test system are investigated in terms of eigenvalue analysis, damped frequency, damping ratio and participation factor. In this study, various conditions are analyzed which include the increase in solar PV penetration into the system and load variation. The results obtained indicate that there is no significant impact of solar PV penetration on the small signal stability of large scaled power syste. © 2017 Institute of Advanced Engineering and Science. All rights reserved.
Sun, 01 Jan 2017 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73312017-01-01T00:00:00Z
- Risk of transient stability using rotor trajectory index as severity functionhttp://dspace.uniten.edu.my/jspui/handle/123456789/7330Title: Risk of transient stability using rotor trajectory index as severity function
Authors: Elghali, E.B.; Marsadek, M.; Ramasamy, A.K.
Abstract: This paper presents a new approach to determine the risk of transient stability. It describes the implementation of rotor trajectory index (RTI) to assess the severity of power systems when it is subjected to a three-phase fault. The (RTI) is proposed as an index used to represent severity of transient instability. Risk of transient stability for three-phase fault is calculated using a well-known risk formula. Risk of transient stability provides a quantitative measure to evaluate the potential loss of synchronism of a generator that takes into account the probability and consequences. RTI index is calculated based on the machines rotor angles obtained at each step of a time domain simulation. RTI is proposed as an index to show the severity of the three-phase fault towards transient stability since it allows a fast and accurate measurement of the degree of stability of the system facing a fault. The proposed technique is implemented on the IEEE 39-bus system. © 2017 Institute of Advanced Engineering and Science. All rights reserved.
Sun, 01 Jan 2017 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73302017-01-01T00:00:00Z
- Performance analysis of the DigSILENT PV model connected to a modelled malaysian distribution networkhttp://dspace.uniten.edu.my/jspui/handle/123456789/7339Title: Performance analysis of the DigSILENT PV model connected to a modelled malaysian distribution network
Authors: Perumal, P.; Ramasamy, A.K.; Teng, A.M.
Abstract: The global growth of Photovoltaic (PV) is remarkable with a total of 135 GW in 2013 from 10GW in 2007. Operation of PV has changed from standalone to grid-connected which brings several challenges. This sudden spike in PV capacity is due to the reduced cost of PV modules over five times in last six years and followed by advancements in PV inverter technologies. Integration of distributed generation alters the unidirectional power system to bidirectional and alongside present's issues such as overvoltage on distribution feeders, overloading of feeders, and undesired exchange of reactive power. Traditional methods that are in practice to control the voltage and reactive power is by controlling the transformer tap changer and using capacitor banks. Volt-VAr control (VVC) activities by traditional methods are no longer appropriate due to intermittency solar irradiation caused by cloud transients. Modern PV inverter has the capabilities to mitigate voltage related issues when they are allowed to operate at power factor other than unity as stated in the IEEE1547-a. Germany and Spain are the pioneer countries in adopting 'smart' inverter operation in accordance with their countries interconnection grid guidelines. Similar operation of PV inverters for Malaysian scenario is prohibited as the current guideline does not allow the participation of PV inverters in voltage control activities. Therefore it is essential to allow the operation of smart inverter for Malaysian scenario, as the number of grid connected PV system is on the rise. This paper extensively analyses the performance of the DigSILENT's PV model control aspects in terms of active power reduction and dynamic voltage support in a test network and validation of static voltage support on modelled Malaysian distribution network according to the new German Grid Code. © 2016 SERSC.
Fri, 01 Jan 2016 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73392016-01-01T00:00:00Z
- Effects of variations in generator inputs for small signal stability studies of a three machine nine bus networkhttp://dspace.uniten.edu.my/jspui/handle/123456789/5017Title: Effects of variations in generator inputs for small signal stability studies of a three machine nine bus network
Authors: Vijiyan, H.N.; Ramasamy, A.K.; Teng, A.M.; Ahmed, S.K.
Abstract: Small signal stability causes small perturbations in the generator that can cause instability in the power network. It is generally known that small signal stability are directly related to the generator and load properties. This paper examines the effects of generator input variations on power system oscillations for a small signal stability study. Eigenvaules and eigenvectors are used to examine the stability of the power system. The dynamic power system's mathematical model is constructed and thus calculated using load flow and small signal stability toolbox on MATLAB. The power system model is based on a 3-machine 9-bus system that was modified to suit this study. In this paper, Participation Factors are a means to gauge the effects of variation in generation with other parameters on the network are also incorporated.
Sat, 01 Jan 2011 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/50172011-01-01T00:00:00Z
- Performance evaluation of doped titanium oxide for low-voltage applicationshttp://dspace.uniten.edu.my/jspui/handle/123456789/7341Title: Performance evaluation of doped titanium oxide for low-voltage applications
Authors: Begum, S.; Daud, I.R.; Ramasamy, A.
Abstract: Varistors are the electronic devices which are used in various industries to protect the electrical and electronic systems from sudden surges. In this research, the electrical properties of titanium dioxide (TiO2) doped with tantalum pentoxide (Ta2O5), tungsten trioxide (WO3), cobalt oxide (Co3O4), and bismuth oxide (Bi2O3) and fired at different temperatures were investigated for low-voltage applications. The adequate amount of dopants at suitable sintering temperature had beneficial effect in improving the properties of TiO2. The relative density was found to be more than 97% of theoretical density when samples sintered between 1300Â°C and 1400Â°C for all composition compared to undoped samples. On the other hand, the addition of dopants enhanced hardness and compressive strength of varistor disks. The average grain size was also increased with the dopants system, making it suitable for low-voltage application. Furthermore, the current-voltage characteristic of the TiO2 revealed a significantly high value of nonlinearity of 19.6. A high dielectric constant of 104 with minimum dissipation factor of 0.002852 at 1 kHz was also obtained, thereby making it suitable for low-voltage application. Â© 2015 The American Ceramic Society.
Thu, 01 Jan 2015 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73412015-01-01T00:00:00Z
- Matlab modeled for real time processing of partial discharge detection using fpga technology with giga hertz data acquisitionhttp://dspace.uniten.edu.my/jspui/handle/123456789/5734Title: Matlab modeled for real time processing of partial discharge detection using fpga technology with giga hertz data acquisition
Authors: Emilliano; Chakrabarty, C.K.; Basri, A.; Ramasamy, A.K.; Devkumar, S.; Hock, G.C.; Badjian, M.H.
Abstract: This paper is purely a model to determine the method to advance Partial Discharge (PD) detection. The research shall involve matlab and Verilog High Development Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA) for the detection and counting of partial discharge signals. © 2009 WASET.ORG.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/57342009-01-01T00:00:00Z
- Identification of electrical appliances using non-intrusive magnetic field and Probabilistic Neural Network (PNN)http://dspace.uniten.edu.my/jspui/handle/123456789/7939Title: Identification of electrical appliances using non-intrusive magnetic field and Probabilistic Neural Network (PNN)
Authors: Mohd Rosdi, N.A.; Nordin, F.H.; Ramasamy, A.K.
Abstract: The electricity waste is severe especially in large organizational buildings where the use of air conditioners, fridges and electrical motors are rampant. Due to lack of energy saving consciousness, users may not switch off this equipment after use. Thus, it would be an advantage if there exist a system that will be able to identify the appliances from one place without the residence having to go and check the state of the appliance or without having to place various sensors intrusively. Since most electrical appliances emit magnetic fields, the paper proposes to use non-intrusive magnetic field signature waveforms to identify the type of appliance used. The magnetic field emitted by table fan, blender and hairdryer are chosen for this purpose. The magnetic field from these three appliances are collected from four different measurement distances i.e. (i) 0cm (ii) 10cm (iii) 30cm and (iv) 60cm. The features of the magnetic field are then extracted and trained offline using the Probabilistic Neural Network (PNN). Once trained, the PNN shows that it is able to successfully identify the appliances regardless of the measurement distance. © 2014 IEEE.
Wed, 01 Jan 2014 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/79392014-01-01T00:00:00Z
- Classification of electrical appliances using magnetic field and probabilistic neural networkhttp://dspace.uniten.edu.my/jspui/handle/123456789/7940Title: Classification of electrical appliances using magnetic field and probabilistic neural network
Authors: Rosdi, N.A.M.; Nordin, F.H.; Ramasamy, A.K.; Mustafa, N.B.A.
Abstract: Many researches have proven that power lines and electrical appliances do emit electromagnetic fields and can be harmful to human's health. However, research on the effect of the magnetic fields on human's health is not yet conclusive. Instead of letting the magnetic fields emit by the electrical appliances be wasted, this paper aims to use the magnetic fields to classify or identify the electrical appliances being used. Table fans, blenders and hairdryers are the electrical appliances used for this purpose where they are divided into three different categories of usage i.e. (i) used less than 1year (ii) used between 1 to 5 years and (iii) used more than 5 years. The magnetic fields are measured from all the nine appliances. Then, the features of the magnetic fields are extracted and trained offline using the Probabilistic Neural Network (PNN). From the results, it is shown that the PNN is able to identify the type of electrical appliance being used regardless of the appliances years of usage using magnetic fields emitted by the appliances. © 2014 IEEE.
Wed, 01 Jan 2014 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/79402014-01-01T00:00:00Z
- Automatic online signature verification: A prototype using neural networkshttp://dspace.uniten.edu.my/jspui/handle/123456789/8032Title: Automatic online signature verification: A prototype using neural networks
Authors: Ahmed, S.K.; Ramasamy, A.K.; Khairuddin, A.S.Mohd.; Omar, J.
Abstract: Signature verification is the process used to recognize an individual's handwritten signature to prevent fraud. In this paper pressure at the pen-tip together with the x, and y coordinates of the signature are measured and features extracted from these are used to verify the signature. A pressure pad was used to obtain signature samples. A signature verification system using SOM neural network was designed in MATLAB to verify the signatures. Results obtained using a prototype system are encouraging. The attractive features of this system are its low cost, low intrusion, good performance and use of an acceptable and natural biometric (the signature). © 2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/80322009-01-01T00:00:00Z
- A study on FVSI index as an indicator for Under Voltage Load Shedding (UVLS)http://dspace.uniten.edu.my/jspui/handle/123456789/9024Title: A study on FVSI index as an indicator for Under Voltage Load Shedding (UVLS)
Authors: Ramasamy, A.; Verayiah, R.; Zainal Abidin, H.I.; Musirin, I.
Abstract: In the time of rapid growth, there is an increase of demand for a reliable and stable power supply. Power utilities are pressured to cater the rising demand with the existing system. Thus, monitoring the voltage stability of the system has become crucial. Under Voltage Load Shedding (UVLS) is one of the many methods that are used to sustain voltage stability. On the other hand, Fast Voltage Stability Index (FVSI) index is proven to be a good indicator for voltage stability in a system. This paper will study on the correlation between FVSI index and UVLS scheme. From the simulation, the results clearly indicate that FVSI index can be used to indentify location to be load shed. ©2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/90242009-01-01T00:00:00Z
- Classification of electrical appliances using magnetic field and probabilistic neural networkhttp://dspace.uniten.edu.my/jspui/handle/123456789/7345Title: Classification of electrical appliances using magnetic field and probabilistic neural network
Authors: Rosdi, N.A.M.; Nordin, F.H.; Ramasamy, A.K.; Mustafa, N.B.A.
Abstract: Many researches have proven that power lines and electrical appliances do emit electromagnetic fields and can be harmful to human's health. However, research on the effect of the magnetic fields on human's health is not yet conclusive. Instead of letting the magnetic fields emit by the electrical appliances be wasted, this paper aims to use the magnetic fields to classify or identify the electrical appliances being used. Table fans, blenders and hairdryers are the electrical appliances used for this purpose where they are divided into three different categories of usage i.e. (i) used less than 1year (ii) used between 1 to 5 years and (iii) used more than 5 years. The magnetic fields are measured from all the nine appliances. Then, the features of the magnetic fields are extracted and trained offline using the Probabilistic Neural Network (PNN). From the results, it is shown that the PNN is able to identify the type of electrical appliance being used regardless of the appliances years of usage using magnetic fields emitted by the appliances. © 2014 IEEE.
Wed, 01 Jan 2014 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/73452014-01-01T00:00:00Z
- Impact of static load on voltage stability of an unbalanced distribution systemhttp://dspace.uniten.edu.my/jspui/handle/123456789/9023Title: Impact of static load on voltage stability of an unbalanced distribution system
Authors: Gunalan, S.; Ramasamy, A.K.; Verayiah, R.
Abstract: Static load which is known for three different characteristics i.e. constant power, constant current and constant impedance shows a different voltage profile because both of their real power and reactive power vary differently as the voltage varies except for constant power. This paper will analyze the impact of each load characteristic individually and also as combination on voltage stability of an IEEE 34 Bus Distribution System by increasing the load demand, and also transient analysis i.e. creating a single phase-to-ground fault i.e. on phase a and balanced three phase fault. The most suitable load to study the voltage stability is also proposed. It was found that, with constant power loads, the reactive power demand increases significantly when load real power and reactive power increases by 25%. Constant current loads and combination loads, on the other hand, the reactive power demand increases but only slightly and the demand is even lesser when with constant impedance loads. However, as the load real power and reactive power increases by 50%, constant power loads causes voltage collapse whilst constant current loads and combination loads turn out to be the next in the order followed by constant impedance loads. In transient analysis, during the single phase fault, with combination loads, phase b voltage increases drastically but only small increment observed in phase c voltage. During the three phase fault, phase b voltage is slightly higher than phase c voltage followed by phase a voltage. As comparison to combination loads, constant power loads causes lesser three phase voltages. After the fault was cleared, a smooth voltage waveform obtained in the period of retaining back to the same pre-fault voltage, however, distortions in the voltage recovering waveform seen when dynamic load included in the system. Constant power load is found to be the suitable load to study the voltage stability. ©2010 IEEE.
Fri, 01 Jan 2010 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/90232010-01-01T00:00:00Z
- Under voltage load shedding (UVLS) study for 746 test bus systemhttp://dspace.uniten.edu.my/jspui/handle/123456789/9025Title: Under voltage load shedding (UVLS) study for 746 test bus system
Authors: Verayiah, R.; Ramasamy, A.; Abidin, H.I.Z.; Musirin, I.
Abstract: Voltage collapse phenomenon is known to be complex and localized in nature but with a widespread effect. The ultimate effect of voltage collapse would be total system collapse which would incur high losses to utility companies. Thus, on- line monitoring of power system stability has become a vital factor for electric utility companies. One of the methods to avoid voltage collapse is to perform Under Voltage Load Shedding (UVLS). Fast Voltage Stability Index (FVSI) index is proven to be a good indicator for voltage stability in a system. This paper analyzes the correlation between FVSI and the placement of UVLS relays for a 746 test bus system. It is found from the simulations results that FVSI index can be used as an indicator for the placement of UVLS relays in a power system network. ©2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/90252009-01-01T00:00:00Z
- Study on P-V Curve and V-Q curve of an unbalanced three- phase system with different static loadshttp://dspace.uniten.edu.my/jspui/handle/123456789/9192Title: Study on P-V Curve and V-Q curve of an unbalanced three- phase system with different static loads
Authors: Ramasamy, A.K.; Verayiah, R.; Abidin, I.Z.; Gunalan, S.; Perumal, P.
Abstract: P-V curve and V-Q curve (often term as Q-V curve) are widely used for planning and operation studies. The P-V curve and V-Q curve of an unbalanced three-phase system, unlike the balanced three-phase system, may not have similar loading margin (LM) and reactive power margin (RPM) on each phase. Therefore, DIgSILENT Programming Language (DPL) has been used to study the maximum loading point (MLP), critical point (CP), and also minimum reactive power point (MRPP) on each phase of an unbalanced three-phase system with different static loads. The tracing direction of P-V curve of each phase and the LM and RPM of each phase obtained from the P-V curve and V-Q curve for different static loads are also discussed. On top of that, continuation power flow (CPF) has become a common method to study the MLP. Hence, a simple 2-bus balanced three-phase system is used to validate the result obtained from the DIgSILENT with CPF method. © 2016, Wydawnictwo SIGMA - N O T Sp. z o.o. All rights reserved.
Fri, 01 Jan 2016 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/91922016-01-01T00:00:00Z
- Study on P-V Curve and V-Q curve of an unbalanced three- phase system with different static loadshttp://dspace.uniten.edu.my/jspui/handle/123456789/9019Title: Study on P-V Curve and V-Q curve of an unbalanced three- phase system with different static loads
Authors: Ramasamy, A.K.; Verayiah, R.; Abidin, I.Z.; Gunalan, S.; Perumal, P.
Abstract: P-V curve and V-Q curve (often term as Q-V curve) are widely used for planning and operation studies. The P-V curve and V-Q curve of an unbalanced three-phase system, unlike the balanced three-phase system, may not have similar loading margin (LM) and reactive power margin (RPM) on each phase. Therefore, DIgSILENT Programming Language (DPL) has been used to study the maximum loading point (MLP), critical point (CP), and also minimum reactive power point (MRPP) on each phase of an unbalanced three-phase system with different static loads. The tracing direction of P-V curve of each phase and the LM and RPM of each phase obtained from the P-V curve and V-Q curve for different static loads are also discussed. On top of that, continuation power flow (CPF) has become a common method to study the MLP. Hence, a simple 2-bus balanced three-phase system is used to validate the result obtained from the DIgSILENT with CPF method. © 2016, Wydawnictwo SIGMA - N O T Sp. z o.o. All rights reserved.
Fri, 01 Jan 2016 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/90192016-01-01T00:00:00Z
- Overcurrent time delay determination using gain scheduled PID controllershttp://dspace.uniten.edu.my/jspui/handle/123456789/9227Title: Overcurrent time delay determination using gain scheduled PID controllers
Authors: Zainul, A.A.; Ramasamy, A.; Abidin, I.Z.; Nagi, F.H.
Abstract: The inverse time overcurrent relay operation is based upon the current setpoint and also the time multiplier setting. Depending on the ratio of the value of the current and the setpoint current together with the value of the time multiplier setting, the amount of time delay for the trip command is determined using the inverse time characteristics. This would mean that the relay is not of the adaptive type and would possibly give a maltripping. This paper uses the concept of PID controller to determine the time delay for the overcurrent relay. ©2009 IEEE.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/92272009-01-01T00:00:00Z
- Matlab modeled for real time processing of partial discharge detection using fpga technology with giga hertz data acquisitionhttp://dspace.uniten.edu.my/jspui/handle/123456789/9336Title: Matlab modeled for real time processing of partial discharge detection using fpga technology with giga hertz data acquisition
Authors: Emilliano; Chakrabarty, C.K.; Basri, A.; Ramasamy, A.K.; Devkumar, S.; Hock, G.C.; Badjian, M.H.
Abstract: This paper is purely a model to determine the method to advance Partial Discharge (PD) detection. The research shall involve matlab and Verilog High Development Language (VHDL) programming to evaluate the use of Field Programming Gate Array (FPGA) for the detection and counting of partial discharge signals. © 2009 WASET.ORG.
Thu, 01 Jan 2009 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/93362009-01-01T00:00:00Z
- Probabilistic analysis of solar photovoltaic output based on historical datahttp://dspace.uniten.edu.my/jspui/handle/123456789/8309Title: Probabilistic analysis of solar photovoltaic output based on historical data
Authors: Zulkifli, N.A.; Razali, N.M.M.; Marsadek, M.; Ramasamy, A.K.
Abstract: Solar photovoltaic (PV) is one of the favorable renewable energy sources since it is considered environmentally friendly. Yet it is still at the infancy stage due to the high cost of PV cells. Furthermore, the PV output is dependent on the solar radiation intermittency and the location of installation. This paper presents a probabilistic analysis of a hypothetical solar photovoltaic system in Peninsular Malaysia. From the recorded meteorological data, an analysis of the probabilistic distribution function of the hourly solar radiation is carried out. A comparison has been made between two different locations in order to analyse their characteristics by using meteorological data of KLIA Sepang and Kuala Terengganu Airport. This paper adopts a method considering a multi-state model instead of two-state model which is used for modeling conventional generator to cater for the intermittency of solar radiation. A linear rounding method is recommended for simplification of the multi-state model for effective computation. The results show that based on irradiance data in Peninsular Malaysia, development of microgrid containing solar photovoltaic power system has a good potential for further development. © 2014 IEEE.
Wed, 01 Jan 2014 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/83092014-01-01T00:00:00Z
- DSP based overcurrent relay using fuzzy bang-bang controllerhttp://dspace.uniten.edu.my/jspui/handle/123456789/9175Title: DSP based overcurrent relay using fuzzy bang-bang controller
Authors: Goh, Y.L.; Ramasamy, A.K.; Nagi, F.H.; Abidin, A.A.Z.
Abstract: Overcurrent relays are very important protection component that require high reliability to maintain high security in power systems. With the new numerical relay technology using digital signal processor (DSP), it is possible to improve the performance of the relay significantly. However, application of DSP in numerical overcurrent relays is limited especially in coordination among the group of relays. The relay must work proficiently to coordinate with the networks in order to avoid mal-operation. Therefore, in this paper, an implementation of overcurrent relay with improved coordination on a DSP, TMS320F2812 is described. The fuzzy bang-bang controller is used as the control strategy for the relay to provide efficient control for overcurrent protection. The performance evaluation of the proposed system is based on steady state analysis, transient state analysis, coordination and lastly the execution time of the DSP. The results obtained using this new proposed controller is very promising. © 2011 Elsevier Ltd. All rights reserved.
Sat, 01 Jan 2011 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/91752011-01-01T00:00:00Z