EPE Association: EPE 2018 - DS3h: Energy Storage Systems

EPE 2018 - DS3h: Energy Storage Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 05: Renewable Energy Power Systems > EPE 2018 - DS3h: Energy Storage Systems

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   Analysis of Battery Fault Tolerance in Modular Multilevel Converter with Integrated Battery Energy Storage System
By Yajun MA [View]
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Abstract: Integrating batteries into modular multilevel converter (MMC) in a distributed manner improves the systemreliability. For further reliability, MMC should also work normally in battery fault condition, which can causeserious unbalance of submodule power. In this paper, submodule voltage redistribution based method isproposed to balance submodule power. On the basis, a graphic method is proposed to study the system fault tolerance, which is mainly affected by the percentage of battery power, power factor and capacitor voltage balancing control method. Then an optimized control strategy with high fault tolerance is proposed. Finally, the analysis and control strategy is verified through MATLAB simulation.

   Considering power quality in energy efficiency of alkaline water electrolyzers
By Joonas KOPONEN [View]
[Download]

Abstract: Water electrolysis may become a major application for power electronics, since hydrogen is a key element for energy storage, renewable hydrocarbons, fuels, and chemicals. Electrolyzers require DC power and their operation depends on electric conditioning. Electrolyzers typically operate at relatively low voltages and high currents, which can be challenging for power electronics. This paper studies the efficiency of alkaline water electrolysis and improvement of electrolyzers from the viewpoint of power electronics.

   Efficiency map to evaluate the performance of kinetic energy storage systems used with renewable generation
By Jorge TORRES [View]
[Download]

Abstract: The paper presents the Kinetic Energy Storage System (KESS) efficiency map to be used inrenewable applications. A description of the different components and their inner system lossesusing models are presented. Finally, a real renewable operation cycle is analysed. The impactthrough the grid oscillations of the Storage System is quantified, as well as the efficiency of theglobal system. Moreover, a methodology is presented to determine the number of KESS modulesto cover the power and energy of the entire cycle.

   EVALUATING THE TECHNO-ECONOMIC FEASIBILITY OF BATTERY TECHNOLOGIES IN THE CONTEXT OF SOLAR HOME SYSTEMS
By Nishant NARAYAN [View]
[Download]

Abstract: Solar Home Systems (SHS) have recently shown an abundant growth in the developing world, which has also largely improved the energy access situation for the un(der)-electrified. Battery storage is the most important component of the SHS, because of both its higher cost and lower lifetime compared to other SHS components. In this study, we show that the upfront battery cost is only half the picture, and that lifetime evaluation can be equally important. Four battery technologies are assessed for their techno-economic feasibility in the context of a given SHS application. The battery's upfront and replacement costs per technology are bundled together in the form of total energy costs, which gives a more realistic measure of the choice of battery size in the system design phase. The methodology presented here can be extended and applied to specific battery technologies and products, and other PV-battery applications in general.

   Simulation based comparisons of mobile and stationary energy storage systems applied for electric transport
By Girts STANA [View]
[Download]

Abstract: Electric public transport infrastructure with its electric trolleybuses plays an important role in large-scale consumption of electrical energy. The most important feature of trolleybuses that are equipped with AC traction drive systems is the ability to generate electrical braking energy. Instead of dissipating in brake resistors, this regenerated energy can be either transferred to other accelerating trolleybus or stored in energy storage system (ESS) for repeated use. However, there are also rather well known technical disadvantages of ESS, for example, mobile ESS causes additional load for trolleybus and stationary ESS might be located so far from trolleybus that most of the energy might be lost in transmission. For this reason, the purpose of this paper was to present a method that compares energy consumptions of trolleybuses unequipped and equipped with mobile or stationary energy storage systems by analyzing the results acquired from simulations of travelling equal distances at equal motion condition cycles. Trolleybus mass increase in case of mobile ESS was considered. Overhead DC line (ODCL) transmission resistance of the portion between substation (SUB) and trolleybus was considered, and ODCL transmission resistance of the portion between stationary ESS and trolleybus was also considered. Losses in both traction drive converter and ESS bidirectional DC/DC converter and also losses in both SUB transformer and SUB rectifier were considered by assuming certain efficiency ratios. Efficiency of regenerated energy storing and substation energy consumption reduction is analyzed and corresponding conclusions are drawn.

   Submodules Fault-Tolerant Control and Analysis of Modular Multilevel Converter with Integrated Battery Energy Storage System
By Zuyao ZE [View]
[Download]

Abstract: In this paper, submodules fault-tolerant control and analysis of Modular multilevel converter(MMC) with integrated battery energy storage system(BESS) are performed under hot reserve. A capacitor control strategy based on the average of the capacitor voltages, which is suitable for both normal operation and submodules fault-tolerant operation is proposed. Besides, difference currents are controlled flowing internally to ensure that the system's external characteristics remain unchanged before and after submodules fault. Then the influence of submodules fault on the arm current is analyzed by Monte Carlo simulation, and the conclusion that the maximum and RMS of the arm current will not exceed 1.1 times of the value of normal operation when redundancy ratio equals to 10\% is drawn. Finally, the correctness of the analysis and control strategies is verified by experiment

   Test bench implementation to calibrate ageing and voltage unbalance in a large series connection of supercapacitors
By Marcos LAFOZ [View]
[Download]

Abstract: This paper presents the study of ageing and the voltage balance needed in a series stack of Electrolytic Double Layer Capacitors (EDLCs). Continuous charging/discharging cycles to different current levels are applied to two prototypes connected in series. In both prototypes the configuration is different. One of them has a better distribution to facilitate the cooling, while the other has a distribution to accelerate ageing due to temperature. This is intended to study the effect of temperature in the ageing of supercapacitors. Similarly, some cells in one of the prototypes have an active balancing system to study and compare the effect of this system to balance the voltage between cells. Data obtained will serve to draw conclusions about the ageing (capacitance decrease and equivalent series resistance), the cooling system design and balance system required as well as the recommendations to operate this energy storage system.

   Unbalanced Power Division in an Interleaved Bidirectional Buck Converter: Theory, Simulation and Control Strategy
By Mauricio DALLA VECCHIA [View]
[Download]

Abstract: This paper proposes a new approach to divide the total power between different legs in an interleavedbidirectional buck converter, based on the Fibonacci sequence. The paper revises the theoretical analysis of the interleaved buck converter, showing the current ripple analysis; a small signal analysis to find the plants, which represent the circuit, to further derive the control strategy; the validation of these plants via simulation; and the control strategy of the circuit, detailing the unbalanced current division. Finally, simulation results showing that the unbalanced power can be used in an interleaved buck configuration and still achieve zero output current ripple are presented. Discussions among the project adaptations for the interleaved legs, with emphasis for the power semiconductors, are also present in this paper.

EPE 2018 - DS3h: Energy Storage Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 05: Renewable Energy Power Systems > EPE 2018 - DS3h: Energy Storage Systems
	[return to parent folder]

	Analysis of Battery Fault Tolerance in Modular Multilevel Converter with Integrated Battery Energy Storage System By Yajun MA	[View] [Download]
Abstract: Integrating batteries into modular multilevel converter (MMC) in a distributed manner improves the systemreliability. For further reliability, MMC should also work normally in battery fault condition, which can causeserious unbalance of submodule power. In this paper, submodule voltage redistribution based method isproposed to balance submodule power. On the basis, a graphic method is proposed to study the system fault tolerance, which is mainly affected by the percentage of battery power, power factor and capacitor voltage balancing control method. Then an optimized control strategy with high fault tolerance is proposed. Finally, the analysis and control strategy is verified through MATLAB simulation.

	Considering power quality in energy efficiency of alkaline water electrolyzers By Joonas KOPONEN	[View] [Download]
Abstract: Water electrolysis may become a major application for power electronics, since hydrogen is a key element for energy storage, renewable hydrocarbons, fuels, and chemicals. Electrolyzers require DC power and their operation depends on electric conditioning. Electrolyzers typically operate at relatively low voltages and high currents, which can be challenging for power electronics. This paper studies the efficiency of alkaline water electrolysis and improvement of electrolyzers from the viewpoint of power electronics.

	Efficiency map to evaluate the performance of kinetic energy storage systems used with renewable generation By Jorge TORRES	[View] [Download]
Abstract: The paper presents the Kinetic Energy Storage System (KESS) efficiency map to be used inrenewable applications. A description of the different components and their inner system lossesusing models are presented. Finally, a real renewable operation cycle is analysed. The impactthrough the grid oscillations of the Storage System is quantified, as well as the efficiency of theglobal system. Moreover, a methodology is presented to determine the number of KESS modulesto cover the power and energy of the entire cycle.

	EVALUATING THE TECHNO-ECONOMIC FEASIBILITY OF BATTERY TECHNOLOGIES IN THE CONTEXT OF SOLAR HOME SYSTEMS By Nishant NARAYAN	[View] [Download]
Abstract: Solar Home Systems (SHS) have recently shown an abundant growth in the developing world, which has also largely improved the energy access situation for the un(der)-electrified. Battery storage is the most important component of the SHS, because of both its higher cost and lower lifetime compared to other SHS components. In this study, we show that the upfront battery cost is only half the picture, and that lifetime evaluation can be equally important. Four battery technologies are assessed for their techno-economic feasibility in the context of a given SHS application. The battery's upfront and replacement costs per technology are bundled together in the form of total energy costs, which gives a more realistic measure of the choice of battery size in the system design phase. The methodology presented here can be extended and applied to specific battery technologies and products, and other PV-battery applications in general.

	Simulation based comparisons of mobile and stationary energy storage systems applied for electric transport By Girts STANA	[View] [Download]
Abstract: Electric public transport infrastructure with its electric trolleybuses plays an important role in large-scale consumption of electrical energy. The most important feature of trolleybuses that are equipped with AC traction drive systems is the ability to generate electrical braking energy. Instead of dissipating in brake resistors, this regenerated energy can be either transferred to other accelerating trolleybus or stored in energy storage system (ESS) for repeated use. However, there are also rather well known technical disadvantages of ESS, for example, mobile ESS causes additional load for trolleybus and stationary ESS might be located so far from trolleybus that most of the energy might be lost in transmission. For this reason, the purpose of this paper was to present a method that compares energy consumptions of trolleybuses unequipped and equipped with mobile or stationary energy storage systems by analyzing the results acquired from simulations of travelling equal distances at equal motion condition cycles. Trolleybus mass increase in case of mobile ESS was considered. Overhead DC line (ODCL) transmission resistance of the portion between substation (SUB) and trolleybus was considered, and ODCL transmission resistance of the portion between stationary ESS and trolleybus was also considered. Losses in both traction drive converter and ESS bidirectional DC/DC converter and also losses in both SUB transformer and SUB rectifier were considered by assuming certain efficiency ratios. Efficiency of regenerated energy storing and substation energy consumption reduction is analyzed and corresponding conclusions are drawn.

	Submodules Fault-Tolerant Control and Analysis of Modular Multilevel Converter with Integrated Battery Energy Storage System By Zuyao ZE	[View] [Download]
Abstract: In this paper, submodules fault-tolerant control and analysis of Modular multilevel converter(MMC) with integrated battery energy storage system(BESS) are performed under hot reserve. A capacitor control strategy based on the average of the capacitor voltages, which is suitable for both normal operation and submodules fault-tolerant operation is proposed. Besides, difference currents are controlled flowing internally to ensure that the system's external characteristics remain unchanged before and after submodules fault. Then the influence of submodules fault on the arm current is analyzed by Monte Carlo simulation, and the conclusion that the maximum and RMS of the arm current will not exceed 1.1 times of the value of normal operation when redundancy ratio equals to 10\% is drawn. Finally, the correctness of the analysis and control strategies is verified by experiment

	Test bench implementation to calibrate ageing and voltage unbalance in a large series connection of supercapacitors By Marcos LAFOZ	[View] [Download]
Abstract: This paper presents the study of ageing and the voltage balance needed in a series stack of Electrolytic Double Layer Capacitors (EDLCs). Continuous charging/discharging cycles to different current levels are applied to two prototypes connected in series. In both prototypes the configuration is different. One of them has a better distribution to facilitate the cooling, while the other has a distribution to accelerate ageing due to temperature. This is intended to study the effect of temperature in the ageing of supercapacitors. Similarly, some cells in one of the prototypes have an active balancing system to study and compare the effect of this system to balance the voltage between cells. Data obtained will serve to draw conclusions about the ageing (capacitance decrease and equivalent series resistance), the cooling system design and balance system required as well as the recommendations to operate this energy storage system.

	Unbalanced Power Division in an Interleaved Bidirectional Buck Converter: Theory, Simulation and Control Strategy By Mauricio DALLA VECCHIA	[View] [Download]
Abstract: This paper proposes a new approach to divide the total power between different legs in an interleavedbidirectional buck converter, based on the Fibonacci sequence. The paper revises the theoretical analysis of the interleaved buck converter, showing the current ripple analysis; a small signal analysis to find the plants, which represent the circuit, to further derive the control strategy; the validation of these plants via simulation; and the control strategy of the circuit, detailing the unbalanced current division. Finally, simulation results showing that the unbalanced power can be used in an interleaved buck configuration and still achieve zero output current ripple are presented. Discussions among the project adaptations for the interleaved legs, with emphasis for the power semiconductors, are also present in this paper.