It is well acknowledged to all that an active equalization strategy can overcome the inconsistency of lithium-ion cell's voltage and state of charge(SOC)in series-connected lithium-ion battery(LIB)pack in the elec...It is well acknowledged to all that an active equalization strategy can overcome the inconsistency of lithium-ion cell's voltage and state of charge(SOC)in series-connected lithium-ion battery(LIB)pack in the electric vehicle application.In this regard,a novel dual threshold trigger mechanism based active equalization strategy(DTTMbased AES)is proposed to overcome the inherent inconsistency of cells and to improve the equalization efficiency for a series-connected LIB pack.First,a modified dual-layer inductor equalization circuit is constructed to make it possible for the energy transfer path optimization.Next,based on the designed dual threshold trigger mechanism provoked by battery voltage and SOC,an active equalization strategy is proposed,each single cell's SOC in the battery packs is estimated using the extended Kalman particle filter algorithm.Besides,on the basis of the modified equalization circuit,the improved particle swarm optimization is adopted to optimize the energy transfer path with aiming to reduce the equalization time.Lastly,the simulation and experimental results are provided to validate the proposed DTTM-based AES.展开更多
The equalization management system is an essential guarantee for the safe,stable,and efficient operation of the power battery pack,mainly composed of the topology of the equalization circuit and the corresponding cont...The equalization management system is an essential guarantee for the safe,stable,and efficient operation of the power battery pack,mainly composed of the topology of the equalization circuit and the corresponding control strategy.This article proposes a novel active balancing control strategy to address the issue of individual cell energy imbalance in battery packs.Firstly,to achieve energy equalization under complex conditions,a two-layer equalization circuit topology is designed,and the efficiency and loss of energy transfer in the equalization process are studied.Furthermore,a directed graph-based approach was proposed to represent the circuit topology equivalently as a multi-weighted network.Combined with a multi-weighted optimal matching algorithm,aims to determine the optimal energy transfer path and reduce equalization losses.In addition,a fuzzy controller that can dynamically adjust the equalization current with the state parameter of the cell as the input condition is designed to optimize the equalization efficiency.Matlab/Simulink software is used to build and simulate the model.The experimental results indicate that,under the same static state,the newly proposed control strategy improves efficiency by 6.08%and enhances equalization speed by 42.03%compared to the maximum value equalization method.The method also effectively improves energy utilization under the same charging and discharging states.展开更多
According to the ion and molecule coexistence theory, the activity model of Fe-Si-B ternary system was es- tablished, and the influence of ratio ：Csi/XZe, boron content and temperature, etc. on the activity of the me...According to the ion and molecule coexistence theory, the activity model of Fe-Si-B ternary system was es- tablished, and the influence of ratio ：Csi/XZe, boron content and temperature, etc. on the activity of the melt com- pound was investigated. The results show that the FeB activity is high in the liquid iron, when Xsl/XFo is 0. 5 ; the ac- tivity of boron increases with increasing the boron content for different contents of xe and xs, and the activity of boron at the ratio xFo = 0.4 is about one order of magnitude higher than that for the XFo = 0. 8; The activities of the melt compound were also affected by temperature, but the influencing extent was little. The equal activity diagrams of silicon and boron were drawn for the first time according to the model results.展开更多
基金supported by the Artificial intelligence technology project of Xi'an Science and Technology Bureau(No.21RGZN0014).
文摘It is well acknowledged to all that an active equalization strategy can overcome the inconsistency of lithium-ion cell's voltage and state of charge(SOC)in series-connected lithium-ion battery(LIB)pack in the electric vehicle application.In this regard,a novel dual threshold trigger mechanism based active equalization strategy(DTTMbased AES)is proposed to overcome the inherent inconsistency of cells and to improve the equalization efficiency for a series-connected LIB pack.First,a modified dual-layer inductor equalization circuit is constructed to make it possible for the energy transfer path optimization.Next,based on the designed dual threshold trigger mechanism provoked by battery voltage and SOC,an active equalization strategy is proposed,each single cell's SOC in the battery packs is estimated using the extended Kalman particle filter algorithm.Besides,on the basis of the modified equalization circuit,the improved particle swarm optimization is adopted to optimize the energy transfer path with aiming to reduce the equalization time.Lastly,the simulation and experimental results are provided to validate the proposed DTTM-based AES.
基金supported by the Natural Science Foundation of Hebei Province(Grant No.F2023502011 and E2023502026)the Chongqing Natural Science Foundation(Grant No.CSTB2023NSCQMSX0359).
文摘The equalization management system is an essential guarantee for the safe,stable,and efficient operation of the power battery pack,mainly composed of the topology of the equalization circuit and the corresponding control strategy.This article proposes a novel active balancing control strategy to address the issue of individual cell energy imbalance in battery packs.Firstly,to achieve energy equalization under complex conditions,a two-layer equalization circuit topology is designed,and the efficiency and loss of energy transfer in the equalization process are studied.Furthermore,a directed graph-based approach was proposed to represent the circuit topology equivalently as a multi-weighted network.Combined with a multi-weighted optimal matching algorithm,aims to determine the optimal energy transfer path and reduce equalization losses.In addition,a fuzzy controller that can dynamically adjust the equalization current with the state parameter of the cell as the input condition is designed to optimize the equalization efficiency.Matlab/Simulink software is used to build and simulate the model.The experimental results indicate that,under the same static state,the newly proposed control strategy improves efficiency by 6.08%and enhances equalization speed by 42.03%compared to the maximum value equalization method.The method also effectively improves energy utilization under the same charging and discharging states.
基金Item Sponsored by National Key Technology Research and Development Program in 11th Five-Year Plan of China(2009BAB45B05)
文摘According to the ion and molecule coexistence theory, the activity model of Fe-Si-B ternary system was es- tablished, and the influence of ratio ：Csi/XZe, boron content and temperature, etc. on the activity of the melt com- pound was investigated. The results show that the FeB activity is high in the liquid iron, when Xsl/XFo is 0. 5 ; the ac- tivity of boron increases with increasing the boron content for different contents of xe and xs, and the activity of boron at the ratio xFo = 0.4 is about one order of magnitude higher than that for the XFo = 0. 8; The activities of the melt compound were also affected by temperature, but the influencing extent was little. The equal activity diagrams of silicon and boron were drawn for the first time according to the model results.
