Emad Manla - Academia.edu (original) (raw)
Papers by Emad Manla
Energies
Ultracapacitors are energy storage devices that have shown outstanding capability in a vast spect... more Ultracapacitors are energy storage devices that have shown outstanding capability in a vast spectrum of applications, mainly in energy storage systems required to deliver short bursts of electrical energy. Ultracapacitors possess high power density while batteries possess high energy density. In this paper, a hybrid energy storage device comprising a lithium-ion ultracapacitor module and a lead acid battery was modeled, built, and tested for vehicular start–stop application, which requires a much larger number of engine cranking events than conventional vehicles. The combination of a lead acid battery with Li-ion ultracapacitors was chosen due to the fact that the vast majority of vehicles utilize lead acid batteries to crank the internal combustion engine. This allows retrofitting this hybrid setup in conventional vehicles along with the start–stop feature without inflicting damage to the already installed lead acid battery. The start–stop feature puts high stress on the lead acid ...
2020 Gulf Southwest Section Conference, Jul 20, 2020
every level possible. One improvement aspect is increasing gas efficiency via hybridization, whic... more every level possible. One improvement aspect is increasing gas efficiency via hybridization, which can be achieved by introducing a feature called start-stop. This feature automatically switches the internal combustion engine off when it idles and switches it back on when it is time to resume driving. This application has been proven to reduce the amount of gas consumption and emission of greenhouse effect gases in the atmosphere. However, the repeated cranking of the engine puts a large amount of stress on the lead acid battery required to perform the cranking, which effectively reduces its life span. This dissertation presents a hybrid energy storage system assembled from a lead acid battery and an ultracapacitor module connected in parallel. The Li-ion ultracapacitor was tested and modeled to predict its behavior when connected in a system requiring pulsed power such as the one proposed. Both test and simulation results show that the proposed hybrid design significantly reduces the cranking loading and stress on the battery. The ultracapacitor module can take the majority of the cranking current, effectively reducing the stress on the battery. The amount of cranking current provided by the ultracapacitor can be easily controlled via controlling the resistance of the cable connected directly between the ultracapacitor module and the car circuitry.
2017 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), 2017
In order to get the desired output from photovoltaic (PV) generation, it is necessary to control ... more In order to get the desired output from photovoltaic (PV) generation, it is necessary to control the power exchange with the grid. Therefore, the calculations of real and reactive power for PV inverters are important. In this study, a novel direct power control (DPC) strategy for three-level single-phase grid-connected SVPWM inverters has been developed. In this strategy, the real and reactive power control and SVPWM are considered in inner loop, while a voltage PI controller is used in outer loop to acquire constant output voltage and provide power reference to the DPC. In addition, the MPPT algorithm is integrated into the control strategy to get the maximum PV output. The performance of the proposed method is verified by simulation results obtained using Matlab/Simulink.
Energies, 2019
Power grid dispatching is a high-risk process, and its execution depends on an available cyber sy... more Power grid dispatching is a high-risk process, and its execution depends on an available cyber system. However, the effects of cyber systems have not caught enough attention in current research on risk assessments in dispatching processes, which may cause optimistic risk results. In order to solve this problem, this paper proposes a risk assessment model that considers the impact of a cyber system on power grid dispatching processes. Firstly, a cyber-physical switchgear state model that integrates the reliability states of both cyber system functions and switchgears is proposed, based on the transition of switchgear states in the dispatching process. Then, the potential effects of each operating step on power grid states are analyzed considering the failure model of cyber-physical system (CPS) components. The risk probabilities and consequences of the power grid states are calculated to quantify the risk index. Finally, the workings and effectiveness of this model are illustrated us...
Energies, 2019
The authors wish to make the following correction to this paper [...]
IEEE Access, 2018
This paper presents a new metaheuristic optimization algorithm, the firefly algorithm (FA), and a... more This paper presents a new metaheuristic optimization algorithm, the firefly algorithm (FA), and an enhanced version of it, called chaos mutation FA (CMFA), for solving power economic dispatch problems while considering various power constraints, such as valve-point effects, ramp rate limits, prohibited operating zones, and multiple generator fuel options. The algorithm is enhanced by adding a new mutation strategy using self-adaptation parameter selection while replacing the parameters with fixed values. The proposed algorithm is also enhanced by a self-adaptation mechanism that avoids challenges associated with tuning the algorithm parameters directed against characteristics of the optimization problem to be solved. The effectiveness of the CMFA method to solve economic dispatch problems with high nonlinearities is demonstrated using five classic test power systems. The solutions obtained are compared with the results of the original algorithm and several methods of optimization proposed in the previous literature. The high performance of the CMFA algorithm is demonstrated by its ability to achieve search solution quality and reliability, which reflected in minimum total cost, convergence speed, and consistency. INDEX TERMS Economic dispatch, firefly algorithm, multiple fuel options, valve-point effects.
Energies, 2018
It is difficult to achieve accurate distribution of reactive power based on conventional droop co... more It is difficult to achieve accurate distribution of reactive power based on conventional droop control due to the line impedance mismatch in an islanded microgrid. An adaptive virtual impendence method based on consensus control of reactive current is proposed in this paper. A distributed control structure without the central controller has been established. In this structure, each distributed generation unit (DG) is an independent agent, one-way communication is used between the adjacent DGs, and the reactive power sharing is equivalent to a problem of reactive power current consensus. It has been proven that the system is asymptotically stable under the proposed control strategy. When the adjacent DG's reactive power is not proportionally distributed, the current weight error term will generate a virtual impedance correction term through the proportional-integral controller based on the reactive current consensus control strategy, thus introducing adaptive virtual impedance to eliminate mismatches in output impedance between DGs. Reactive power auto-proportional distribution can be achieved without knowing the line impedance. At the same time, the power control loop is simplified and the virtual impedance compensation angle is employed to compensate the decreased reference voltage magnitude and varied phase angle due to the introduction of the virtual impedance, so the stability of the system can be improved. Finally, the correctness and effectiveness of the proposed strategy are verified by modeling analysis and microgrid simulations.
2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015
Ultracapacitors can provide high power density, high efficiency, and extended cycle life in vario... more Ultracapacitors can provide high power density, high efficiency, and extended cycle life in various applications. Lead acid batteries, on the other hand, offer high energy density, low cost, and good performance in low temperature. In this paper, a hybrid energy storage device comprised of a Lithium-ion ultracapacitor module and a lead acid battery is modeled, built, and tested for the vehicular start-stop application. Hundreds of cranking events have been performed with the single lead acid battery and the hybrid storage and the performance of the systems have been evaluated and compared. Mathematical derivation, analysis, and a thorough energy storage aging study have also been conducted and presented.
2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015
This paper presents two of the most promising compact energy storage types, Li-ion batteries and ... more This paper presents two of the most promising compact energy storage types, Li-ion batteries and ultracapacitors, for grid applications. Different types of lithium-ion batteries are discussed and compared and a generic electrical model for this type of batteries is presented, which models the battery dynamics, capacity, efficiency, and performance. Characteristics and electrical equivalent model of the Li-ion capacitors are also presented and discussed. The electrical models are verified for both devices by conducting extensive testing. Various grid level applications of these energy storage elements including renewable integration, ancillary services, energy time-shifting, and applications in islanded grids are discussed.
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2015
Accurate knowledge of the electrical characteristics of an energy storage device is of high impor... more Accurate knowledge of the electrical characteristics of an energy storage device is of high importance when utilized in any power system to achieve proper charging and discharging modes without inflicting any damage to its structure. In this paper, a Li-ion ultracapacitor, a hybrid type of energy storage, is thoroughly studied. This type of ultracapacitors has high energy density, high power density, high efficiency, long cycle life, and superior performance under high temperatures. Testing, analysis, and modeling of this energy storage device are presented in details. A battery-based model and a capacitor-based model are proposed. A series of dc and ac tests has been conducted at various temperatures to develop an electrical model spanning, the entire domain of temperatures under which the ultracapacitor can normally and safely operate. These models have been verified for model accuracy via simulation and comparison with the test results for both a single ultracapacitor cell and a 360 V ultracapacitor module built in the laboratory. Both coulombic and energy efficiency have also been investigated at different temperatures and current ratings.
2011 IEEE Energy Conversion Congress and Exposition, 2011
The main problem of renewable energy sources is their intermittency. Integration of energy storag... more The main problem of renewable energy sources is their intermittency. Integration of energy storage devices with renewable energy systems can offer solution to this problem simply by storing excess produced energy for utilization when needed later on. Energy storage devices are also essential for other applications such as automotive. Accurate knowledge of the electrical attributes and expected response of an
2009 35th Annual Conference of IEEE Industrial Electronics, 2009
... Emad Manla and Adel Nasiri Power Electronics and Electric Drives Laboratory University of Wis... more ... Emad Manla and Adel Nasiri Power Electronics and Electric Drives Laboratory University of Wisconsin-Milwaukee Email: nasiri@uwm.edu, www.uwm.edu ... Present system output may be computed with present input and present state onlypast input values need not be stored. ...
IEEE Transactions on Industrial Electronics, 2010
Energy storage devices such as lithium-ion and nickel-metal hydrate batteries and ultracapacitors... more Energy storage devices such as lithium-ion and nickel-metal hydrate batteries and ultracapacitors have been considered for utilization in plug-in hybrid electric vehicles (HEVs) and HEVs to improve efficiency and performance and reduce gas mileage. In this paper, we analyze and model an advanced energy storage device, namely, zinc bromide, for vehicular applications. This system has high energy and power density, high efficiency, and long life. A series of tests has been conducted on the storage to create an electrical model of the system. The modeling results show that the open-circuit voltage of the battery is a direct function of the battery's state of charge (SOC). In addition, the battery internal resistance is also a function of SOC at constant temperature. A Kalman filtering technique is also designed to adjust the estimated SOC according to battery current.
International Journal of Heat and Technology
Energies
Ultracapacitors are energy storage devices that have shown outstanding capability in a vast spect... more Ultracapacitors are energy storage devices that have shown outstanding capability in a vast spectrum of applications, mainly in energy storage systems required to deliver short bursts of electrical energy. Ultracapacitors possess high power density while batteries possess high energy density. In this paper, a hybrid energy storage device comprising a lithium-ion ultracapacitor module and a lead acid battery was modeled, built, and tested for vehicular start–stop application, which requires a much larger number of engine cranking events than conventional vehicles. The combination of a lead acid battery with Li-ion ultracapacitors was chosen due to the fact that the vast majority of vehicles utilize lead acid batteries to crank the internal combustion engine. This allows retrofitting this hybrid setup in conventional vehicles along with the start–stop feature without inflicting damage to the already installed lead acid battery. The start–stop feature puts high stress on the lead acid ...
2020 Gulf Southwest Section Conference, Jul 20, 2020
every level possible. One improvement aspect is increasing gas efficiency via hybridization, whic... more every level possible. One improvement aspect is increasing gas efficiency via hybridization, which can be achieved by introducing a feature called start-stop. This feature automatically switches the internal combustion engine off when it idles and switches it back on when it is time to resume driving. This application has been proven to reduce the amount of gas consumption and emission of greenhouse effect gases in the atmosphere. However, the repeated cranking of the engine puts a large amount of stress on the lead acid battery required to perform the cranking, which effectively reduces its life span. This dissertation presents a hybrid energy storage system assembled from a lead acid battery and an ultracapacitor module connected in parallel. The Li-ion ultracapacitor was tested and modeled to predict its behavior when connected in a system requiring pulsed power such as the one proposed. Both test and simulation results show that the proposed hybrid design significantly reduces the cranking loading and stress on the battery. The ultracapacitor module can take the majority of the cranking current, effectively reducing the stress on the battery. The amount of cranking current provided by the ultracapacitor can be easily controlled via controlling the resistance of the cable connected directly between the ultracapacitor module and the car circuitry.
2017 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), 2017
In order to get the desired output from photovoltaic (PV) generation, it is necessary to control ... more In order to get the desired output from photovoltaic (PV) generation, it is necessary to control the power exchange with the grid. Therefore, the calculations of real and reactive power for PV inverters are important. In this study, a novel direct power control (DPC) strategy for three-level single-phase grid-connected SVPWM inverters has been developed. In this strategy, the real and reactive power control and SVPWM are considered in inner loop, while a voltage PI controller is used in outer loop to acquire constant output voltage and provide power reference to the DPC. In addition, the MPPT algorithm is integrated into the control strategy to get the maximum PV output. The performance of the proposed method is verified by simulation results obtained using Matlab/Simulink.
Energies, 2019
Power grid dispatching is a high-risk process, and its execution depends on an available cyber sy... more Power grid dispatching is a high-risk process, and its execution depends on an available cyber system. However, the effects of cyber systems have not caught enough attention in current research on risk assessments in dispatching processes, which may cause optimistic risk results. In order to solve this problem, this paper proposes a risk assessment model that considers the impact of a cyber system on power grid dispatching processes. Firstly, a cyber-physical switchgear state model that integrates the reliability states of both cyber system functions and switchgears is proposed, based on the transition of switchgear states in the dispatching process. Then, the potential effects of each operating step on power grid states are analyzed considering the failure model of cyber-physical system (CPS) components. The risk probabilities and consequences of the power grid states are calculated to quantify the risk index. Finally, the workings and effectiveness of this model are illustrated us...
Energies, 2019
The authors wish to make the following correction to this paper [...]
IEEE Access, 2018
This paper presents a new metaheuristic optimization algorithm, the firefly algorithm (FA), and a... more This paper presents a new metaheuristic optimization algorithm, the firefly algorithm (FA), and an enhanced version of it, called chaos mutation FA (CMFA), for solving power economic dispatch problems while considering various power constraints, such as valve-point effects, ramp rate limits, prohibited operating zones, and multiple generator fuel options. The algorithm is enhanced by adding a new mutation strategy using self-adaptation parameter selection while replacing the parameters with fixed values. The proposed algorithm is also enhanced by a self-adaptation mechanism that avoids challenges associated with tuning the algorithm parameters directed against characteristics of the optimization problem to be solved. The effectiveness of the CMFA method to solve economic dispatch problems with high nonlinearities is demonstrated using five classic test power systems. The solutions obtained are compared with the results of the original algorithm and several methods of optimization proposed in the previous literature. The high performance of the CMFA algorithm is demonstrated by its ability to achieve search solution quality and reliability, which reflected in minimum total cost, convergence speed, and consistency. INDEX TERMS Economic dispatch, firefly algorithm, multiple fuel options, valve-point effects.
Energies, 2018
It is difficult to achieve accurate distribution of reactive power based on conventional droop co... more It is difficult to achieve accurate distribution of reactive power based on conventional droop control due to the line impedance mismatch in an islanded microgrid. An adaptive virtual impendence method based on consensus control of reactive current is proposed in this paper. A distributed control structure without the central controller has been established. In this structure, each distributed generation unit (DG) is an independent agent, one-way communication is used between the adjacent DGs, and the reactive power sharing is equivalent to a problem of reactive power current consensus. It has been proven that the system is asymptotically stable under the proposed control strategy. When the adjacent DG's reactive power is not proportionally distributed, the current weight error term will generate a virtual impedance correction term through the proportional-integral controller based on the reactive current consensus control strategy, thus introducing adaptive virtual impedance to eliminate mismatches in output impedance between DGs. Reactive power auto-proportional distribution can be achieved without knowing the line impedance. At the same time, the power control loop is simplified and the virtual impedance compensation angle is employed to compensate the decreased reference voltage magnitude and varied phase angle due to the introduction of the virtual impedance, so the stability of the system can be improved. Finally, the correctness and effectiveness of the proposed strategy are verified by modeling analysis and microgrid simulations.
2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015
Ultracapacitors can provide high power density, high efficiency, and extended cycle life in vario... more Ultracapacitors can provide high power density, high efficiency, and extended cycle life in various applications. Lead acid batteries, on the other hand, offer high energy density, low cost, and good performance in low temperature. In this paper, a hybrid energy storage device comprised of a Lithium-ion ultracapacitor module and a lead acid battery is modeled, built, and tested for the vehicular start-stop application. Hundreds of cranking events have been performed with the single lead acid battery and the hybrid storage and the performance of the systems have been evaluated and compared. Mathematical derivation, analysis, and a thorough energy storage aging study have also been conducted and presented.
2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015
This paper presents two of the most promising compact energy storage types, Li-ion batteries and ... more This paper presents two of the most promising compact energy storage types, Li-ion batteries and ultracapacitors, for grid applications. Different types of lithium-ion batteries are discussed and compared and a generic electrical model for this type of batteries is presented, which models the battery dynamics, capacity, efficiency, and performance. Characteristics and electrical equivalent model of the Li-ion capacitors are also presented and discussed. The electrical models are verified for both devices by conducting extensive testing. Various grid level applications of these energy storage elements including renewable integration, ancillary services, energy time-shifting, and applications in islanded grids are discussed.
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2015
Accurate knowledge of the electrical characteristics of an energy storage device is of high impor... more Accurate knowledge of the electrical characteristics of an energy storage device is of high importance when utilized in any power system to achieve proper charging and discharging modes without inflicting any damage to its structure. In this paper, a Li-ion ultracapacitor, a hybrid type of energy storage, is thoroughly studied. This type of ultracapacitors has high energy density, high power density, high efficiency, long cycle life, and superior performance under high temperatures. Testing, analysis, and modeling of this energy storage device are presented in details. A battery-based model and a capacitor-based model are proposed. A series of dc and ac tests has been conducted at various temperatures to develop an electrical model spanning, the entire domain of temperatures under which the ultracapacitor can normally and safely operate. These models have been verified for model accuracy via simulation and comparison with the test results for both a single ultracapacitor cell and a 360 V ultracapacitor module built in the laboratory. Both coulombic and energy efficiency have also been investigated at different temperatures and current ratings.
2011 IEEE Energy Conversion Congress and Exposition, 2011
The main problem of renewable energy sources is their intermittency. Integration of energy storag... more The main problem of renewable energy sources is their intermittency. Integration of energy storage devices with renewable energy systems can offer solution to this problem simply by storing excess produced energy for utilization when needed later on. Energy storage devices are also essential for other applications such as automotive. Accurate knowledge of the electrical attributes and expected response of an
2009 35th Annual Conference of IEEE Industrial Electronics, 2009
... Emad Manla and Adel Nasiri Power Electronics and Electric Drives Laboratory University of Wis... more ... Emad Manla and Adel Nasiri Power Electronics and Electric Drives Laboratory University of Wisconsin-Milwaukee Email: nasiri@uwm.edu, www.uwm.edu ... Present system output may be computed with present input and present state onlypast input values need not be stored. ...
IEEE Transactions on Industrial Electronics, 2010
Energy storage devices such as lithium-ion and nickel-metal hydrate batteries and ultracapacitors... more Energy storage devices such as lithium-ion and nickel-metal hydrate batteries and ultracapacitors have been considered for utilization in plug-in hybrid electric vehicles (HEVs) and HEVs to improve efficiency and performance and reduce gas mileage. In this paper, we analyze and model an advanced energy storage device, namely, zinc bromide, for vehicular applications. This system has high energy and power density, high efficiency, and long life. A series of tests has been conducted on the storage to create an electrical model of the system. The modeling results show that the open-circuit voltage of the battery is a direct function of the battery's state of charge (SOC). In addition, the battery internal resistance is also a function of SOC at constant temperature. A Kalman filtering technique is also designed to adjust the estimated SOC according to battery current.
International Journal of Heat and Technology