Efficiency Characteristic of a High-Power Reconfigurable Battery with Series-Connected Topology

Engelhardt, Jan; Zepter, Jan Martin; Gabderakhmanova, Tatiana; Marinelli, Mattia

doi:10.23919/ipec-himeji2022-ecce53331.2022.9807176

Cited by 5 publications

(2 citation statements)

References 14 publications

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“…Because the high-power prototype hasn't been completely built, we analyzed the efficiency of the high-power reconfigurable battery pack using Pspice with the parameters of TABLE Ⅱ. The SPICE-level component models were obtained from the manufacturers and the resistance values of PCB and connecting terminals were estimated according to the references [16], [31], where a high-power reconfigurable battery pack was built and the actual resistances were measured. Fig.…”

Section: ⅴ Additional Power Loss Analysismentioning

confidence: 99%

Hierarchical State-of-Charge Balancing and Second-Harmonic Current Suppressing Control With a Scalable DC Reconfigurable Battery Pack

Chen,

Liu,

Zhang

et al. 2024

IEEE Trans. Power Electron.

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This paper develops a scalable dc reconfigurable battery pack (RBP) and the accompanying hierarchical balancing algorithm. The battery cells in the RBP are divided into several modules, and each module is equipped with a slave controller that is only responsible for a subset of cells. The system controller performs the closed-loop control and allocates the desired voltage steps into battery modules. The hierarchical algorithm significantly reduces communication and computation requirements for large-scale applications. Moreover, considering the second-harmonic current (SHC) widely existing in a single-phase dc/ac system, which may induce the aging of battery cells, the dc RBP is used to suppress the SHC for the first time without an additional central dc/dc converter. Due to the high output voltage quality and lowfrequency operation of the dc RBP, the filter size can be significantly reduced and the efficiency of the system can be improved. Experimental validation of the proposed control scheme is presented using a dc RBP containing 48 3-Ah 18650 lithium-ion cells. Experimental results show that the proposed method can effectively balance battery cells and suppress the SHC.

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Section: ⅴ Additional Power Loss Analysismentioning

confidence: 99%

Hierarchical State-of-Charge Balancing and Second-Harmonic Current Suppressing Control With a Scalable DC Reconfigurable Battery Pack

Chen,

Liu,

Zhang

et al. 2024

IEEE Trans. Power Electron.

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show abstract

“…The reconfigurable topology and variable voltage means the components can only connect to battery strings and not directly to each other, hence all energy flowing through the system do so via a battery. This is a novel design that removes the need for interfacing power converters [17] [18].…”

Section: ~= ~=mentioning

confidence: 99%

Battery Buffered EV Fast Chargers on Bornholm: Charging Patterns and Grid Integration

Bowen

Engelhardt

Gabderakhmanova

et al. 2022

2022 57th International Universities Power Engineering Conference (UPEC)

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The widespread adoption of electric vehicles (EVs) is a vital step in the reduction of emissions within the transport sector. However, the development of public fast charging infrastructure and the proper modeling of EV charging behaviours is required to enable this adoption. This paper presents charging data and patterns observed at a battery buffered fast charging DC microgrid on the Danish island of Bornholm. The charging sessions observed at this single site tend to be shorter with lower total energy transfer compared to studies with a wider scope. An atypical uptake of charges with higher than average energy transfer late in the evening is also observed. A simulation based study using this charging data to examine the effectiveness of the battery buffers at facilitating EV fast charging at reduced grid capacities is then presented. This study shows that the Bornholm DC microgrid would have been able to supply all observed EV charging at a reduced grid capacity of 11 kW, enabling such a system to provide EV fast charging at a much wider range of locations.

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Efficiency Characteristic and Operating Area of High-Power Reconfigurable Batteries

Engelhardt,

Zepter,

Marinelli

et al. 2024

IEEE Trans. on Ind. Applicat.

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Reconfigurable batteries can change their cell topology in real time, which enables them to adapt their voltage during operation. This unique capability makes interfacing power converters redundant in applications where batteries are directly coupled with other DC components or systems. The present paper characterizes a 104 kWh prototype of a reconfigurable battery for high power applications, and derives equations for calculating the battery efficiency for the complete operating area. The battery can adapt its voltage from 0 V up to 1200 V, and reaches power values of 240 kW for charging, and 280 kW for discharging. The results are presented in efficiency maps, showing the dependency on voltage, power, and state of charge. Moreover, the efficiency characteristic is compared to a conventional battery with fixed cell topology and DC-DC converter. The reconfigurable battery can operate at a wider voltage range and achieves better efficiency up to an average power of 44.6 kW during charging, and 46.7 kW during discharging. Conversely, the conventional system performs better above these thresholds. Finally, the presented model can be used to optimize the design of reconfigurable battery strings, and to accurately size such systems for specific applications and purposes.

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Efficiency Characteristic of a High-Power Reconfigurable Battery with Series-Connected Topology

Cited by 5 publications

References 14 publications

Hierarchical State-of-Charge Balancing and Second-Harmonic Current Suppressing Control With a Scalable DC Reconfigurable Battery Pack

Hierarchical State-of-Charge Balancing and Second-Harmonic Current Suppressing Control With a Scalable DC Reconfigurable Battery Pack

Battery Buffered EV Fast Chargers on Bornholm: Charging Patterns and Grid Integration

Efficiency Characteristic and Operating Area of High-Power Reconfigurable Batteries

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