DC–DC Converter with Reduced Circulating Current in On-board Battery Chargers for Electric Transportation

2019 ◽  
Author(s):  
A.V.J.S. Praneeth ◽  
Naveen Yalla ◽  
Sheldon S Williamson
Keyword(s):  
Circulating Current ◽  
Battery Chargers

scholarly journals Estimation of the Hot Swap Circulation Current of a Multiple Parallel Lithium Battery System with an Artificial Neural Network Model

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1448
Author(s):  
Nam-Gyu Lim ◽  
Jae-Yeol Kim ◽  
Seongjun Lee
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Lithium Battery ◽  
Battery Pack ◽  
Battery Management ◽  
Ann Model ◽  
Battery System ◽  
Load Current ◽  
Circulating Current ◽  
Artificial Neural

Battery applications, such as electric vehicles, electric propulsion ships, and energy storage systems, are developing rapidly, and battery management issues are gaining attention. In this application field, a battery system with a high capacity and high power in which numerous battery cells are connected in series and parallel is used. Therefore, research on a battery management system (BMS) to which various algorithms are applied for efficient use and safe operation of batteries is being conducted. In general, maintenance/replacement of multi-series/multiple parallel battery systems is only possible when there is no load current, or the entire system is shut down. However, if the circulating current generated by the voltage difference between the newly added battery and the existing battery pack is less than the allowable current of the system, the new battery can be connected while the system is running, which is called hot swapping. The circulating current generated during the hot-swap operation is determined by the battery’s state of charge (SOC), the parallel configuration of the battery system, temperature, aging, operating point, and differences in the load current. Therefore, since there is a limit to formulating a circulating current that changes in size according to these various conditions, this paper presents a circulating current estimation method, using an artificial neural network (ANN). The ANN model for estimating the hot-swap circulating current is designed for a 1S4P lithium battery pack system, consisting of one series and four parallel cells. The circulating current of the ANN model proposed in this paper is experimentally verified to be able to estimate the actual value within a 6% error range.

scholarly journals Comparison of Advanced Charge Strategies for Modular Cascaded Battery Chargers

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3361
Author(s):  
Nicolas T. D. Fernandes ◽  
Anderson Rocha ◽  
Danilo Brandao ◽  
Braz C. Filho
Keyword(s):  
Control Strategies ◽  
Measure Data ◽  
Capacity Fade ◽  
Battery Lifetime ◽  
Control Techniques ◽  
Battery Model ◽  
Battery Chargers ◽  
Battery Energy Storage Systems ◽  
Battery Energy ◽  
Photovoltaic Plant

Although the literature extensively covers the development of battery chargers control strategies, a comparison of these strategies remains a literary gap. The inherent conditions (i.e., State of Health and State of Charge) of each unit in the Battery Energy Storage Systems directly influence the charger control techniques for extending battery lifetime, which makes modular battery chargers an appealing topology for this analysis. This work groups charger control strategies presented in the literature into two: Adapted SoC strategies, directly linked to the field of overstress management, and SoH strategies, which are directly linked to the field of wear-out management. The methodology for comparing the control strategies encompasses battery lifetime, charger, and photovoltaic plant models. Three distinct cases were simulated using real measure data from a solar power plant and a battery model provided by MathWorks®. The results evidence that the Capacity Fade and Energy Throughput strongly depend on the strategy. The controller action evidences the previous statement, as the strategies have different goals that are related to each field. Furthermore, this work analyses the effect of the estimation process in the action of the controller.

scholarly journals Lifetime and reliability improvements in modular multilevel converters using controlled circulating current

2021 ◽  
Author(s):  
Nasiru B. Kadandani ◽  
Mohamed Dahidah ◽  
Salaheddine Ethni ◽  
Musbahu Muhammad
Keyword(s):  
Control Method ◽  
Semiconductor Devices ◽  
Junction Temperature ◽  
Multilevel Converters ◽  
Control Approach ◽  
Circulating Current ◽  
Inherent Feature ◽  
Modular Multilevel Converters ◽  
Current Loading ◽  
Laboratory Prototype

AbstractCirculating current has been an inherent feature of modular multilevel converters (MMC), which results in second-order harmonics on the arms currents. If not properly controlled, the circulating current can affect the lifetime and reliability of a converter by increasing the current loading, loss distribution, and junction temperature of its semiconductor devices. This paper proposes controlled circulating current injection as a means of improving the lifetime and reliability of an MMC. The proposed method involves modifying the reference modulating signals of the converter arms to include the controlled differential voltage as an offset. The junction temperature of the semiconductor devices obtained from an electro-thermal simulation is processed to deduce the lifetime and reliability of the converter. The obtained results are benchmarked against a case where the control method is not incorporated. The incorporation of the proposed control method results in a 68.25% increase in the expected lifetime of the converter and a 3.06% increase on its reliability index. Experimental results of a scaled down laboratory prototype validate the effectiveness of the proposed control approach.

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