sunil Abeyratne | University of Peradeniya (original) (raw)

Papers by sunil Abeyratne

Research paper thumbnail of 電流形インバータのための直列共振DCリンクの改良と制御法の研究

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Research paper thumbnail of Improved Series Resonant DC-Links for Current-Source Inverters and Control Aspects

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Research paper thumbnail of Modeling and Detection of Dynamic Position Sensor Offset Error in PMSM Drives

Rotor position information obtained through a position sensor is crucial for proper field-orient... more Rotor position information obtained through a position sensor is crucial for proper field-oriented control (FOC) of permanent magnet synchronous machine based high dynamic energy conversion applications. In applications such as transportation and industrial, PMSM energy conversion systems are subjected to harsh environmental conditions such as vibration, shock, and thermal shock causing mechanical interfaces holding positions sensors to fail, introducing error to the position measurement. A dynamic position sensor offset error (DPSOE), being such a failure mode has the potential to degrade system torque output or more adversely, reverse machine torque output that may cause catastrophic outcomes. This paper evaluates different DPSOE scenarios, presents an approach to model the failure mode for analysis and proposes two novel and robust DPSOE detection methods for PMSM drive systems. The proposed detection methods are analytically proven and supported by simulation and experimental r...

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Research paper thumbnail of Digital Creation of Color Illusion Fabricated by Overlaying Different Colored Translucent Textiles Using Images

2019 14th Conference on Industrial and Information Systems (ICIIS)

Overlaying different colored textiles which are translucent is a straight forward task to complet... more Overlaying different colored textiles which are translucent is a straight forward task to complete physically, in contrast this task is difficult to achieve digitally. Amount of information obtained from an image is limited, which is a major difficulty faced when using images to identify the features of a textile such as color, material, texture, thickness and transparency. An algorithmic approach is taken based on three hypotheses; random superimposing, background replacement and color augmentation. These techniques are based on; color identification, background replacement, random selection, pixel superimposing, color blending and image color augmenting. The algorithms are researched, implemented, experimented in-depth and critically compared. Four algorithms are implemented, two based on randomly superimposing and one each based on background replacement and color augmentation. Background replacement algorithm was hardly able to complete the task effectively, thus is the lowest ranked algorithm. In contrast, randomly superimposing and color augmenting algorithms were capable of carrying out the task successfully. Randomly superimposing costed the least time to complete, but the generated images were unnatural whereas color augmenting produced a perfectly natural image though the color of the final output was inaccurate. Further refining the color prediction algorithm is proposed to develop a more effective system.

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Research paper thumbnail of Disambiguation of Uniform Demagnetization Fault from Position Sensor Fault in FOC PMSM Applications

Electrification of higher torque density applications in the transportation sector and robotics ... more Electrification of higher torque density applications in the transportation sector and robotics sector are primarily met with permanent magnet synchronous machines (PMSMs), attributing to their unique properties. However, wide operating temperatures, field weakening controls, and low-quality magnets, lead to uniform demagnetization of rotor magnets. Demagnetization in torque control applications reduce the effective output torque as the output torque is proportional to rotor flux level. Detection of such rotor demagnetization is essential and only second to few key faults from the system perspective. A simple and common approach to detect uniform demagnetization in a sensored-FOC PMSM drive system in torque control mode is discussed in this paper with experimental results emulating uniform demagnetization effect. The false positive nature in the proposed algorithm under a position sensor offset error is discussed, followed by a disambiguation strategy, which are primary contributio...

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Research paper thumbnail of Decentralized Controller Using Active Power Control With the Aid of Sensitivity Matrix

2021 IEEE 16th International Conference on Industrial and Information Systems (ICIIS), 2021

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Research paper thumbnail of Managing Spinning Reserves for Power System Stability under Increased Renewable Energy Penetration

Increased penetration levels of renewable energy-based generation pose technical challenges to st... more Increased penetration levels of renewable energy-based generation pose technical challenges to stable operation of a power system, particularly under lacking storage. The power system becomes more vulnerable to significant system frequency variations due to lack of system inertia. This paper proposes a remedial measure to fulfill the inertia requirement using the spinning reserves in an optimal way to improve the inertial response. The system frequency behavior during a contingency under inadequate system inertia, is visualized with the aid of a model power system. The effectiveness of the proposed method, under varying generator configurations, is analyzed using a modified IEEE 09 bus system in the PSCAD platform. Numerical experiments are conducted to demonstarte encouraging results.

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Research paper thumbnail of Hard-Switching Losses in Power FETs: The Role of Output Capacitance

IEEE Transactions on Power Electronics, 2021

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Research paper thumbnail of A power electronics assisted emergency vehicle starter

2014 16th International Power Electronics and Motion Control Conference and Exposition, 2014

This research touches a major problem in automobile industry. Which is that, the engine cranking ... more This research touches a major problem in automobile industry. Which is that, the engine cranking fails when the battery is drained to a certain depth of discharge, though the battery has enough energy for cranking, due to the dynamic behaviour of the internal resistance upon the state of charge of a lead acid battery. Our work is focused on finding-out the capability of cranking an internal combustion engine using such a battery while utilizing the battery-energy with the use of a power electronics assisted methodology. This paper consists of the study on the requirements of a vehicle engine for a healthy start, the characteristics of a battery at both starting and non-starting conditions, and the power electronic assisted method of compensating the starting requirements of the vehicles' electrical system at a non-starting condition. In that direction, field tests were carried out and the results were analyzed. Finally the proposed electronic assisted vehicle starting method was simulated and proved as a concept to be implemented practically. Here we have used a memory Hicorder to record data in field tests and MATLAB Simulink tool as the simulation workbench.

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Research paper thumbnail of Comparative analysis of speed of convergence of MPPT techniques

2011 6th International Conference on Industrial and Information Systems, 2011

ABSTRACT In order to extract maximum power available from a solar cell in a photovoltaic system, ... more ABSTRACT In order to extract maximum power available from a solar cell in a photovoltaic system, maximum power point tracking should be activated. Several maximum power point tracking (MPPT) techniques have been developed over the past years. In an environment where, varying irradiance levels prevail, time taken to track the maximum power point is important. In this paper, three widely used MPPT tracking techniques are compared with regard to their convergence speed at irradiance disturbances. The results of the simulation study are validated on a laboratory prototype and findings are presented. It has been shown that the incremental conductance method is superior at irradiance transients.

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Research paper thumbnail of A Voltage Regulating Radial Feeder with Enhanced Hosting Capacity under Constrained conditions

2021 IEEE 16th International Conference on Industrial and Information Systems (ICIIS), 2021

Integration of photo-voltaic (PV) systems to Low Voltage (LV) utility-networks, causes over volta... more Integration of photo-voltaic (PV) systems to Low Voltage (LV) utility-networks, causes over voltage conditions under heavy PV penetration. The associated-load-masking, on the contrary, surfaces under voltage conditions. Customarily, the PV-inverters are designed to trip-off when, over and under voltage limits are detected, as a protective measure. As a result, poor voltage-control strategies at PV inverters, inevitably lower the yield from the PV system due to the discontinuity of PV connections along. In the proposed approach, a solution to the problem is presented that avoids discontinuities as much as possible, and it maximizes the yield through a voltage-coupled power-control strategy. The methodology is implemented and verified, based on a simulation study. The solution is offline type, and it uses a hybrid model of OpenDSS and MATLAB. With the aid of inputs such as load distribution, positions of the existing PV panels, and the ones to be connected, the line is modelled on OpenDSS and the optimum solution is obtained through MATLAB. The proposed optimization algorithm is also illustrated. The maximum active power that can be delivered by a customer based on their distance along the feeder, while considering the installed/requested capacity of each customer were analyzed, for varying inverter power factors, to maximize the hosting capacity of a feeder. It is expected that the methodology would be highly useful for utilities in contracting customer PV connections.

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Research paper thumbnail of Model-based fault diagnosis and prognosis of dynamic systems: a review

Procedia Manufacturing

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Research paper thumbnail of Zero-current-switching pulse charger for high capacity batteries in renewable energy applications

Journal of the National Science Foundation of Sri Lanka, 2016

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Research paper thumbnail of Dynamic Voltage Control of a Smart Distribution Transformer

Control and Intelligent Systems, 2016

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Research paper thumbnail of Improvements for the pulse charger with zero current switching and isolation for electric vehicles

2013 Ieee 8th International Conference on Industrial and Information Systems, Dec 1, 2013

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Research paper thumbnail of EPE/ Fourth European Power Electronics Conference, Sept. 3-6, 1991, vol. 2, pp. 8-12

ABSTRACT

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Research paper thumbnail of Simulation and fabrication of a maximum power point tracker monitoring and validating system

2011 6th International Conference on Industrial and Information Systems, 2011

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Research paper thumbnail of A simple battery chemistry identification and implementation technique for a self adaptable charger

2009 International Conference on Industrial and Information Systems (ICIIS), 2009

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Research paper thumbnail of Operational restrictions with maximum power extraction of DFIG connected wind farms

2008 IEEE International Conference on Sustainable Energy Technologies, 2008

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Research paper thumbnail of Soft Switching fast charger for batteries used in Renewable Energy applications and electric vehicles

High Capacity Li-ion and Pb-acid batteries are widely used in present Renewable Energy and EV app... more High Capacity Li-ion and Pb-acid batteries are widely used in present Renewable Energy and EV applications. Consequently, charging these batteries in a minimum amount of time whilst maintaining efficiency is crucial. The need for fast charging has brought up the method of Pulse Charging. However, present pulse charging methods which involve hard-switching, pose problems due to switching losses in the semiconductor devices. This paper presents a Fast Pulse Charging mechanism for High Capacity Pb-acid and Li-ion Batteries which minimizes switching losses by Soft Switching. The operation of the methodology is centered on the Fully Clamped Quasi-resonant DC Link Converter which strategically generates current pulses to charge the battery in both Constant Current (CC) and Constant Voltage (CV) phases. Switching losses are minimized by exploiting Zero Current Switching (ZCS), and the simulated results show that this can be achieved for higher switching frequencies further reducing the cir...

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Research paper thumbnail of 電流形インバータのための直列共振DCリンクの改良と制御法の研究

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Improved Series Resonant DC-Links for Current-Source Inverters and Control Aspects

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Modeling and Detection of Dynamic Position Sensor Offset Error in PMSM Drives

Rotor position information obtained through a position sensor is crucial for proper field-orient... more Rotor position information obtained through a position sensor is crucial for proper field-oriented control (FOC) of permanent magnet synchronous machine based high dynamic energy conversion applications. In applications such as transportation and industrial, PMSM energy conversion systems are subjected to harsh environmental conditions such as vibration, shock, and thermal shock causing mechanical interfaces holding positions sensors to fail, introducing error to the position measurement. A dynamic position sensor offset error (DPSOE), being such a failure mode has the potential to degrade system torque output or more adversely, reverse machine torque output that may cause catastrophic outcomes. This paper evaluates different DPSOE scenarios, presents an approach to model the failure mode for analysis and proposes two novel and robust DPSOE detection methods for PMSM drive systems. The proposed detection methods are analytically proven and supported by simulation and experimental r...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Digital Creation of Color Illusion Fabricated by Overlaying Different Colored Translucent Textiles Using Images

2019 14th Conference on Industrial and Information Systems (ICIIS)

Overlaying different colored textiles which are translucent is a straight forward task to complet... more Overlaying different colored textiles which are translucent is a straight forward task to complete physically, in contrast this task is difficult to achieve digitally. Amount of information obtained from an image is limited, which is a major difficulty faced when using images to identify the features of a textile such as color, material, texture, thickness and transparency. An algorithmic approach is taken based on three hypotheses; random superimposing, background replacement and color augmentation. These techniques are based on; color identification, background replacement, random selection, pixel superimposing, color blending and image color augmenting. The algorithms are researched, implemented, experimented in-depth and critically compared. Four algorithms are implemented, two based on randomly superimposing and one each based on background replacement and color augmentation. Background replacement algorithm was hardly able to complete the task effectively, thus is the lowest ranked algorithm. In contrast, randomly superimposing and color augmenting algorithms were capable of carrying out the task successfully. Randomly superimposing costed the least time to complete, but the generated images were unnatural whereas color augmenting produced a perfectly natural image though the color of the final output was inaccurate. Further refining the color prediction algorithm is proposed to develop a more effective system.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Disambiguation of Uniform Demagnetization Fault from Position Sensor Fault in FOC PMSM Applications

Electrification of higher torque density applications in the transportation sector and robotics ... more Electrification of higher torque density applications in the transportation sector and robotics sector are primarily met with permanent magnet synchronous machines (PMSMs), attributing to their unique properties. However, wide operating temperatures, field weakening controls, and low-quality magnets, lead to uniform demagnetization of rotor magnets. Demagnetization in torque control applications reduce the effective output torque as the output torque is proportional to rotor flux level. Detection of such rotor demagnetization is essential and only second to few key faults from the system perspective. A simple and common approach to detect uniform demagnetization in a sensored-FOC PMSM drive system in torque control mode is discussed in this paper with experimental results emulating uniform demagnetization effect. The false positive nature in the proposed algorithm under a position sensor offset error is discussed, followed by a disambiguation strategy, which are primary contributio...

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Research paper thumbnail of Decentralized Controller Using Active Power Control With the Aid of Sensitivity Matrix

2021 IEEE 16th International Conference on Industrial and Information Systems (ICIIS), 2021

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Research paper thumbnail of Managing Spinning Reserves for Power System Stability under Increased Renewable Energy Penetration

Increased penetration levels of renewable energy-based generation pose technical challenges to st... more Increased penetration levels of renewable energy-based generation pose technical challenges to stable operation of a power system, particularly under lacking storage. The power system becomes more vulnerable to significant system frequency variations due to lack of system inertia. This paper proposes a remedial measure to fulfill the inertia requirement using the spinning reserves in an optimal way to improve the inertial response. The system frequency behavior during a contingency under inadequate system inertia, is visualized with the aid of a model power system. The effectiveness of the proposed method, under varying generator configurations, is analyzed using a modified IEEE 09 bus system in the PSCAD platform. Numerical experiments are conducted to demonstarte encouraging results.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Hard-Switching Losses in Power FETs: The Role of Output Capacitance

IEEE Transactions on Power Electronics, 2021

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Research paper thumbnail of A power electronics assisted emergency vehicle starter

2014 16th International Power Electronics and Motion Control Conference and Exposition, 2014

This research touches a major problem in automobile industry. Which is that, the engine cranking ... more This research touches a major problem in automobile industry. Which is that, the engine cranking fails when the battery is drained to a certain depth of discharge, though the battery has enough energy for cranking, due to the dynamic behaviour of the internal resistance upon the state of charge of a lead acid battery. Our work is focused on finding-out the capability of cranking an internal combustion engine using such a battery while utilizing the battery-energy with the use of a power electronics assisted methodology. This paper consists of the study on the requirements of a vehicle engine for a healthy start, the characteristics of a battery at both starting and non-starting conditions, and the power electronic assisted method of compensating the starting requirements of the vehicles' electrical system at a non-starting condition. In that direction, field tests were carried out and the results were analyzed. Finally the proposed electronic assisted vehicle starting method was simulated and proved as a concept to be implemented practically. Here we have used a memory Hicorder to record data in field tests and MATLAB Simulink tool as the simulation workbench.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Comparative analysis of speed of convergence of MPPT techniques

2011 6th International Conference on Industrial and Information Systems, 2011

ABSTRACT In order to extract maximum power available from a solar cell in a photovoltaic system, ... more ABSTRACT In order to extract maximum power available from a solar cell in a photovoltaic system, maximum power point tracking should be activated. Several maximum power point tracking (MPPT) techniques have been developed over the past years. In an environment where, varying irradiance levels prevail, time taken to track the maximum power point is important. In this paper, three widely used MPPT tracking techniques are compared with regard to their convergence speed at irradiance disturbances. The results of the simulation study are validated on a laboratory prototype and findings are presented. It has been shown that the incremental conductance method is superior at irradiance transients.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Voltage Regulating Radial Feeder with Enhanced Hosting Capacity under Constrained conditions

2021 IEEE 16th International Conference on Industrial and Information Systems (ICIIS), 2021

Integration of photo-voltaic (PV) systems to Low Voltage (LV) utility-networks, causes over volta... more Integration of photo-voltaic (PV) systems to Low Voltage (LV) utility-networks, causes over voltage conditions under heavy PV penetration. The associated-load-masking, on the contrary, surfaces under voltage conditions. Customarily, the PV-inverters are designed to trip-off when, over and under voltage limits are detected, as a protective measure. As a result, poor voltage-control strategies at PV inverters, inevitably lower the yield from the PV system due to the discontinuity of PV connections along. In the proposed approach, a solution to the problem is presented that avoids discontinuities as much as possible, and it maximizes the yield through a voltage-coupled power-control strategy. The methodology is implemented and verified, based on a simulation study. The solution is offline type, and it uses a hybrid model of OpenDSS and MATLAB. With the aid of inputs such as load distribution, positions of the existing PV panels, and the ones to be connected, the line is modelled on OpenDSS and the optimum solution is obtained through MATLAB. The proposed optimization algorithm is also illustrated. The maximum active power that can be delivered by a customer based on their distance along the feeder, while considering the installed/requested capacity of each customer were analyzed, for varying inverter power factors, to maximize the hosting capacity of a feeder. It is expected that the methodology would be highly useful for utilities in contracting customer PV connections.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Model-based fault diagnosis and prognosis of dynamic systems: a review

Procedia Manufacturing

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Zero-current-switching pulse charger for high capacity batteries in renewable energy applications

Journal of the National Science Foundation of Sri Lanka, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Dynamic Voltage Control of a Smart Distribution Transformer

Control and Intelligent Systems, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Improvements for the pulse charger with zero current switching and isolation for electric vehicles

2013 Ieee 8th International Conference on Industrial and Information Systems, Dec 1, 2013

Bookmarks Related papers MentionsView impact

Research paper thumbnail of EPE/ Fourth European Power Electronics Conference, Sept. 3-6, 1991, vol. 2, pp. 8-12

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Simulation and fabrication of a maximum power point tracker monitoring and validating system

2011 6th International Conference on Industrial and Information Systems, 2011

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A simple battery chemistry identification and implementation technique for a self adaptable charger

2009 International Conference on Industrial and Information Systems (ICIIS), 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Operational restrictions with maximum power extraction of DFIG connected wind farms

2008 IEEE International Conference on Sustainable Energy Technologies, 2008

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Soft Switching fast charger for batteries used in Renewable Energy applications and electric vehicles

High Capacity Li-ion and Pb-acid batteries are widely used in present Renewable Energy and EV app... more High Capacity Li-ion and Pb-acid batteries are widely used in present Renewable Energy and EV applications. Consequently, charging these batteries in a minimum amount of time whilst maintaining efficiency is crucial. The need for fast charging has brought up the method of Pulse Charging. However, present pulse charging methods which involve hard-switching, pose problems due to switching losses in the semiconductor devices. This paper presents a Fast Pulse Charging mechanism for High Capacity Pb-acid and Li-ion Batteries which minimizes switching losses by Soft Switching. The operation of the methodology is centered on the Fully Clamped Quasi-resonant DC Link Converter which strategically generates current pulses to charge the battery in both Constant Current (CC) and Constant Voltage (CV) phases. Switching losses are minimized by exploiting Zero Current Switching (ZCS), and the simulated results show that this can be achieved for higher switching frequencies further reducing the cir...

Bookmarks Related papers MentionsView impact