Dr K. Ramalingam - Academia.edu (original) (raw)
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Papers by Dr K. Ramalingam
Arabian Journal for Science and Engineering, 2019
In this paper, the distribution static compensator model based on the bond graph (BG) domain is p... more In this paper, the distribution static compensator model based on the bond graph (BG) domain is presented. The methodology is applied to reactive power compensation in distribution systems where a traditional phase lock loop for sensing the AC grid frequency is not needed. The control law is developed using the inverse BG model, which is extracted using the bi-causality concept. In this way, it is possible to perform the distribution system analysis completely in the BG domain. This means that the graphical model is inverted by obtaining the open-loop control law structure, and then the close loop is formulated. The balanced and unbalance conditions are analyzed, generating a control structure that is robust and efficient. The efficacy of the proposed methodology is shown through: partial and complete system simulations in MATLAB/Simulink ® (MATLAB r2015b, Natick, Massachusetts, 01760, USA), as well as experimental laboratory tests. Such tests use: the rapid control prototyping concept and the real-time simulator Opal-RT Technologies ® (Montreal, QC, Canada).
Lecture Notes in Computer Science, 2013
This paper proposes a Monte Carlo analysis for forecasting the MW load of plug-in electric vehicl... more This paper proposes a Monte Carlo analysis for forecasting the MW load of plug-in electric vehicles. The method considers the number of vehicles in a city, Wh/km, km per vehicle, vehicles on chargers, and power factor of chargers. Using the Monte Carlo method, the range of the MW load is forecasted, considering the associated ranges of the various parameters and variables.
2008 Joint International Conference on Power System Technology and IEEE Power India Conference, 2008
This paper conducts load-flow analysis of a five-bus test system containing voltage sensitive loa... more This paper conducts load-flow analysis of a five-bus test system containing voltage sensitive loads. Generalized equations that are suitable for the voltage sensitive loads and applicable to the Newton-Raphson method are developed. Three load flow studies are carried out. In the first study, all loads are assumed as constant power loads. In the other two studies, all loads are assumed
Journal of Cerebral Blood Flow & Metabolism, 1993
Autoradiograms obtained after middle cerebral artery occlusion (MCAO) in spontaneously hypertensi... more Autoradiograms obtained after middle cerebral artery occlusion (MCAO) in spontaneously hypertensive rats show that the 99mTc complex of a 2-nitroimidazole-derivatized propylene amine oxime (BMS-181321) is selectively retained in acutely ischemic brain before disruption of the blood-brain barrier (BBB), but not in the ischemic infarct. BMS-181321 is therefore a marker of ischemic tissue at risk of infarction and its uptake, unlike that of x-ray and magnetic resonance contrast agents, does not require disruption of the BBB. In keeping with this conclusion, we have found that the single-pass cerebral extraction fraction of BMS-181321 is 0.67 at normal rat whole-brain blood flow. Sequential single-photon emission computed tomographic images obtained from cats after MCAO show that the initial distribution of BMS-181321 approximates regional CBF and that selective retention subsequently produces a positive image within the ischemic territory. BMS-181321 is the first Tc complex able to ind...
International Journal of Electrical Power & Energy Systems, 2008
This paper describes the method of estimating the transmission line parameters from voltage, curr... more This paper describes the method of estimating the transmission line parameters from voltage, current, and power measurements at the two ends of the line. This becomes necessary if a new parallel transmission line is constructed between two substations due to load growth or if an underground cable replaces an overhead line and the overall parameters of the paralleled lines or
2010 Joint International Conference on Power Electronics, Drives and Energy Systems & 2010 Power India, 2010
This paper describes the method of estimating the underground cable multi-conductor parameters fr... more This paper describes the method of estimating the underground cable multi-conductor parameters from measurements of voltage and current magnitudes and phase angles at the two ends of the cable. This becomes necessary to determine if an underground cable needs replacement due to changes in the cable parameters due to ageing. A single cable consisting of core and sheath in a
A random number theory is used to forecast future GW demand in India in the next 10 years for non... more A random number theory is used to forecast future GW demand in India in the next 10 years for non renewable and renewable energy sources based on the present cost of Generation.
The Plug-in Electric Vehicles (PEVs) are the Battery Electric Vehicles (BEVs) and Plug-in Hybrid ... more The Plug-in Electric Vehicles (PEVs) are the Battery Electric Vehicles (BEVs) and Plug-in Hybrid Electric Vehicles (PHEVs). PEVs will dominate the transportation in the personal mobility mode and in the automobile market by 2030. Widespread adoption of PEVs brings potential, social and economic benefits. The focus on promoting use of electric vehicles in road transportation is very essential to meet the climate change targets and manage the ever hiking prices of fast depleting fossil fuels. However, there are lots of uncertainties in the market about the acceptability of PEVs by customers due to the capital and operation costs and inadequate infrastructure for charging systems. The penetration level in the market is not encouraging, in spite of incentives offered by Governments. Manufacturers are also not sure of the market, even though predictions are strong and attractive. Major manufacturers, however, are already ready with their plans to introduce electric vehicles to mass market. The use of PEVs has both technological and market issues and impacts. Series of research works have been reported to address the issues related to technologies and its impacts on political, economic, environmental, infrastructural and market potential aspects. Works dealing with suitable infrastructure such as charging stations and use of smart grids are reported. These steps are aimed to bring down the capital and operational costs that are comparable to the costing of conventional transport vehicles. The penetration level of PEVs in transportation will accordingly increase and keep the climate targets met and conserve fossil fuels for use in other economic segments. An overview on these issues is presented in this chapter.
Arabian Journal for Science and Engineering, 2019
In this paper, the distribution static compensator model based on the bond graph (BG) domain is p... more In this paper, the distribution static compensator model based on the bond graph (BG) domain is presented. The methodology is applied to reactive power compensation in distribution systems where a traditional phase lock loop for sensing the AC grid frequency is not needed. The control law is developed using the inverse BG model, which is extracted using the bi-causality concept. In this way, it is possible to perform the distribution system analysis completely in the BG domain. This means that the graphical model is inverted by obtaining the open-loop control law structure, and then the close loop is formulated. The balanced and unbalance conditions are analyzed, generating a control structure that is robust and efficient. The efficacy of the proposed methodology is shown through: partial and complete system simulations in MATLAB/Simulink ® (MATLAB r2015b, Natick, Massachusetts, 01760, USA), as well as experimental laboratory tests. Such tests use: the rapid control prototyping concept and the real-time simulator Opal-RT Technologies ® (Montreal, QC, Canada).
Lecture Notes in Computer Science, 2013
This paper proposes a Monte Carlo analysis for forecasting the MW load of plug-in electric vehicl... more This paper proposes a Monte Carlo analysis for forecasting the MW load of plug-in electric vehicles. The method considers the number of vehicles in a city, Wh/km, km per vehicle, vehicles on chargers, and power factor of chargers. Using the Monte Carlo method, the range of the MW load is forecasted, considering the associated ranges of the various parameters and variables.
2008 Joint International Conference on Power System Technology and IEEE Power India Conference, 2008
This paper conducts load-flow analysis of a five-bus test system containing voltage sensitive loa... more This paper conducts load-flow analysis of a five-bus test system containing voltage sensitive loads. Generalized equations that are suitable for the voltage sensitive loads and applicable to the Newton-Raphson method are developed. Three load flow studies are carried out. In the first study, all loads are assumed as constant power loads. In the other two studies, all loads are assumed
Journal of Cerebral Blood Flow & Metabolism, 1993
Autoradiograms obtained after middle cerebral artery occlusion (MCAO) in spontaneously hypertensi... more Autoradiograms obtained after middle cerebral artery occlusion (MCAO) in spontaneously hypertensive rats show that the 99mTc complex of a 2-nitroimidazole-derivatized propylene amine oxime (BMS-181321) is selectively retained in acutely ischemic brain before disruption of the blood-brain barrier (BBB), but not in the ischemic infarct. BMS-181321 is therefore a marker of ischemic tissue at risk of infarction and its uptake, unlike that of x-ray and magnetic resonance contrast agents, does not require disruption of the BBB. In keeping with this conclusion, we have found that the single-pass cerebral extraction fraction of BMS-181321 is 0.67 at normal rat whole-brain blood flow. Sequential single-photon emission computed tomographic images obtained from cats after MCAO show that the initial distribution of BMS-181321 approximates regional CBF and that selective retention subsequently produces a positive image within the ischemic territory. BMS-181321 is the first Tc complex able to ind...
International Journal of Electrical Power & Energy Systems, 2008
This paper describes the method of estimating the transmission line parameters from voltage, curr... more This paper describes the method of estimating the transmission line parameters from voltage, current, and power measurements at the two ends of the line. This becomes necessary if a new parallel transmission line is constructed between two substations due to load growth or if an underground cable replaces an overhead line and the overall parameters of the paralleled lines or
2010 Joint International Conference on Power Electronics, Drives and Energy Systems & 2010 Power India, 2010
This paper describes the method of estimating the underground cable multi-conductor parameters fr... more This paper describes the method of estimating the underground cable multi-conductor parameters from measurements of voltage and current magnitudes and phase angles at the two ends of the cable. This becomes necessary to determine if an underground cable needs replacement due to changes in the cable parameters due to ageing. A single cable consisting of core and sheath in a
A random number theory is used to forecast future GW demand in India in the next 10 years for non... more A random number theory is used to forecast future GW demand in India in the next 10 years for non renewable and renewable energy sources based on the present cost of Generation.
The Plug-in Electric Vehicles (PEVs) are the Battery Electric Vehicles (BEVs) and Plug-in Hybrid ... more The Plug-in Electric Vehicles (PEVs) are the Battery Electric Vehicles (BEVs) and Plug-in Hybrid Electric Vehicles (PHEVs). PEVs will dominate the transportation in the personal mobility mode and in the automobile market by 2030. Widespread adoption of PEVs brings potential, social and economic benefits. The focus on promoting use of electric vehicles in road transportation is very essential to meet the climate change targets and manage the ever hiking prices of fast depleting fossil fuels. However, there are lots of uncertainties in the market about the acceptability of PEVs by customers due to the capital and operation costs and inadequate infrastructure for charging systems. The penetration level in the market is not encouraging, in spite of incentives offered by Governments. Manufacturers are also not sure of the market, even though predictions are strong and attractive. Major manufacturers, however, are already ready with their plans to introduce electric vehicles to mass market. The use of PEVs has both technological and market issues and impacts. Series of research works have been reported to address the issues related to technologies and its impacts on political, economic, environmental, infrastructural and market potential aspects. Works dealing with suitable infrastructure such as charging stations and use of smart grids are reported. These steps are aimed to bring down the capital and operational costs that are comparable to the costing of conventional transport vehicles. The penetration level of PEVs in transportation will accordingly increase and keep the climate targets met and conserve fossil fuels for use in other economic segments. An overview on these issues is presented in this chapter.