scholarly journals An Active and Passive Hybrid Battery Equalization Strategy Used in Group and between Groups

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1744
Author(s):  
Mingyu Gao ◽  
Jifeng Qu ◽  
Hao Lan ◽  
Qixing Wu ◽  
Huipin Lin ◽  
...  
Keyword(s):  
Lithium Battery ◽  
Bottom Layer ◽  
Equilibrium Strategy ◽  
Forward Converter ◽  
Flyback Converter ◽  
Equilibrium Strategies ◽  
Simulation And Experiment ◽  
Series Of Experiments ◽  
Battery Cells

Active battery equalization and passive battery equalization are two important methods which can solve the inconsistency of battery cells in lithium battery groups. In this paper, a new hybrid battery equalization strategy combinfigureing the active equalizing method with a passive equalizing method is proposed. Among them, the implementation of the active equalizing method uses the bidirectional Flyback converter and Forward converter. This hybrid equalizing strategy adopts the concept of hierarchical equilibrium: it can be divided into two layers, the top layer is the equalization between groups, and the bottom layer is the equalization of group. There are three active equilibrium strategies and one passive equilibrium strategy. For verification purposes, a series of experiments were conducted in MATLAB 2018b/Simulink platform. The simulation and experiment results show that this hybrid battery equalizing method is efficient and feasible.

Online State of Charge Estimation for Battery of Electric Vehicle Using Sigma-Points Kalman Filters

2013 ◽  
Vol 427-429 ◽  
pp. 824-829
Author(s):  
Li Cun Fang ◽  
Gang Xu ◽  
Tian Li Li ◽  
Ke Min Zhu
Keyword(s):  
Electric Vehicle ◽  
Kalman Filters ◽  
Hybrid Electric Vehicle ◽  
Lithium Battery ◽  
Cell Model ◽  
Operating Conditions ◽  
State Of Charge ◽  
Battery Cell ◽  
Soc Estimation ◽  
Simulation And Experiment

An accurate state-of-charge (SOC) estimation of the hybrid electric vehicle (HEV) and electric vehicle (EV) battery pack is a difficult task to be performed online in a vehicle because of the noisy and low accurate measurements and the wide operating conditions in which the vehicle battery can operate. A Sigma-points Kalman Filters (SPKF) algorithm based on an improved Lithium battery cell model to estimate the SOC of a Lithium battery cell is proposed in this paper. The simulation and experiment results show the effectiveness and ease of implementation of the proposed technique.

scholarly journals Modeling of Lithium Battery Cells for Plug-In Hybrid Vehicles

2013 ◽  
Vol 13 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Dong-Hyun Shin ◽  
Jin-Beom Jeong ◽  
Tae-Hoon Kim ◽  
Hee-Jun Kim
Keyword(s):  
Lithium Battery ◽  
Hybrid Vehicles ◽  
Battery Cells

scholarly journals Double-Layer E-Structure Equalization Circuit for Series Connected Battery Strings

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4252
Author(s):  
Shungang Xu ◽  
Kai Gao ◽  
Xiaobing Zhang ◽  
Kangle Li
Keyword(s):  
Double Layer ◽  
Control Strategy ◽  
Process Simulation ◽  
Adjacent Cell ◽  
Boost Converters ◽  
In Series ◽  
Simulation And Experiment ◽  
Working Principle ◽  
Maximum Voltage ◽  
Battery Cells

In order to eliminate the voltage imbalance among battery cells when they are connected in series, the paper proposes a double-layer E-structure (DLE) equalizer based on bidirectional buck–boost converters, which has the advantage of quick equalization speed and can be applied to arbitrary number batteries. Furthermore, a novel two-stage equalization control strategy is proposed for the DLE equalizer to decrease maximum voltage gap between the maximum and minimum voltage cells. The paper analyses the working principle of proposed equalizer in detail and describes the detailed design of the control strategy and implement process. Simulation and experiment results show that the proposed equalizer can improve equalization performance of battery cells compared with adjacent cell-to-cell (AC2C) equalizer.

scholarly journals A Novel Active Cell Balancing Circuit and Charging Strategy in Lithium Battery Pack

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4473 ◽  
Author(s):  
Shing-Lih Wu ◽  
Hung-Cheng Chen ◽  
Chih-Hsuan Chien
Keyword(s):  
Lithium Battery ◽  
Cell Voltage ◽  
Active Cell ◽  
Battery Pack ◽  
Battery Cell ◽  
Voltage Difference ◽  
Third Stage ◽  
Maximum Cell ◽  
Cell Balancing ◽  
Battery Cells

A novel, active cell balancing circuit and charging strategy in lithium battery pack is proposed in this paper. The active cell balancing circuit mainly consists of a battery voltage measurement circuit and switch control circuit. First, all individual cell voltages are measured by an MSP430 microcontroller equipped with an isolation circuit and a filter circuit. Then, the maximum cell voltage difference is calculated by subtracting the minimum cell voltage from the maximum cell voltage. When the maximum cell voltage difference exceeds 0.05 V, the balancing action starts to carry on. The MSP430 microcontroller output controls signals to close the switches corresponding to the battery cell with the maximum voltage. At this time, the balancing charge power performs a balancing charge for other batteries, except for the one that is switched on. In addition, a three-stage balancing charge strategy is also proposed in this paper to achieve the goal of speedy charging with balancing action. In the first stage, a 0.5 C balancing current is used to perform pre-balanced charging on all battery cells until the maximum cell voltage difference is less than 0.05 V, which is required for entry to the second stage of charging. In the second stage, constant current charging of 1 C, coupled with 0.2 C balancing current charging is carried out, until the maximum battery cell voltage reaches 4.2 V, which is required for entry into the third stage of charging. In the third stage, a constant voltage charging is coupled with 0.2 C balancing current charging, until the maximum battery cell voltage reaches 4.25 V, which is required to complete the balancing charge. The imbalance of power between the battery cells during battery pack charging, which reduces battery charging efficiency and battery life, is thus effectively improved. In this paper, a six-cells-in-series and two-in parallel lithium battery pack is used to perform a balancing charge test. Test results show that the battery cells in the battery pack are capable of quickly completing a balancing charge under different initial voltages, the maximum voltage difference is reduced to within the range of 0.05 V, and the total time required for each balancing charge is approximately 3600 s.

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