scholarly journals A ΔSOC-based equalization strategy applied to industry

2020 ◽  
Author(s):  
Maonan Wang ◽  
Chun Chang ◽  
Feng Ji
Keyword(s):  
Open Circuit ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Battery Cell ◽  
New Strategy ◽  
The Difference ◽  
Relative Errors ◽  
The Relationship ◽  
Battery Cells

Abstract The voltage-based equalization strategy is widely used in the industry because the voltage (U) of the battery cell is very easy to obtain, but it is difficult to provide an accurate parameter for the battery management system (BMS). This study proposes a new equalization strategy, which is based on the difference between the state of charge (SOC) of any two battery cells in the battery pack, that is, a ΔSOC-based equalization strategy. The new strategy is not only as simple as the voltage-based equalization strategy, but it can also provide an accurate parameter for the BMS. Simply put, using the relationship between the open circuit voltage and the SOC of the battery pack, the proposed strategy can convert the difference between the voltage of the battery cells into ΔSOC, which renders a good performance. Additionally, the required parameters are all from the BMS, and no additional calculation is required, which makes the strategy as simple as the voltage-based balancing strategy. The four experiments show that the relative errors of ΔSOC estimated by the ΔSOC-based equalization strategy are 0.37%, 0.39%, 0.1% and 0.17%, and thereby demonstrate that the ΔSOC-based equalization strategy proposed in this study shows promise in replacing the voltage-based equalization strategy within the industry to obtain better performance.

scholarly journals Environmental testing for reliable battery management system in electric vehicle

2020 ◽  
Vol 1517 (1) ◽  
pp. 012025
Author(s):  
J Raharjo ◽  
A Wikarta ◽  
I Sidharta ◽  
M N Yuniarto ◽  
M I Firdaus ◽  
...  
Keyword(s):  
Management System ◽  
Cell Voltage ◽  
Temperature Cycling ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Environmental Testing ◽  
The Difference ◽  
Main Component ◽  
Battery Cells

Abstract The Battery management system (BMS) is a main component in the battery pack system for electric vehicles (EV). The function of BMS is to monitor battery cells such as; cell voltage, cell temperature, and current in the battery pack. Moreover BMS also able to balance the voltage of the cells so the difference in voltage of the cells can be minimized. By having many of these functions, BMS can identify battery health based on these parameters. With such an important function, in this paper, BMS was tested to determine its reliability. The standard testing for BMS reliability is the Environment test. In the environment test, some things that are conducted in the environment test are initial temperature cycling. From the environment, the test can be generated information to assess the quality of the BMS following its function. Furthermore, it can reduce the cost to inspect every battery cells in the packs. With the environment test as a basis for BMS reliability tester, hopefully, good quality is obtained. Future development in BMS reliability testing can also be conducted to improve reliability.

scholarly journals Active battery balancing system for electric vehicles based on cell charger

2021 ◽  
Vol 12 (3) ◽  
pp. 1729
Author(s):  
Amin Amin ◽  
Alexander Christantho Budiman ◽  
Sunarto Kaleg ◽  
Sudirja Sudirja ◽  
Abdul Hapid
Keyword(s):  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Test Results ◽  
Negative Effects ◽  
Battery Cell ◽  
Active Balancing ◽  
A Cell ◽  
The Difference ◽  
The Cost

Cell imbalance can cause negative effects such as early stopping of the battery charging and discharging process which can reduce its capacity. In the previous active balancing research, the energy used for the balancing process was taken from the cell or battery pack, resulting in drop of electric vehicle driving range. In this paper, a cell charger based battery balancing system is proposed with a reduction in the number of switches. The use of a cell charger aims to increase the usable energy of the battery pack, since the energy used for the balancing process is taken directly from the grid. The use of fewer switches aims to reduce the cost and space used on the battery management system (BMS) hardware. The charger used for the balancing process has a maximum current of 3 A and a maximum voltage of 3.65 V while the number of switches used is <em>n</em>+5 for <em>n</em> batteries. A 15S1P 200 Ah LiFePO<sub>4</sub> battery pack consists of 15 cells used for testing purpose. The test results show that the time needed to equalize the 15 cell battery voltage reaches 6 hours from the difference between the highest and lowest battery cell voltages of 145.1 mV to 15.1 mV.

scholarly journals Active battery balancing system for electric vehicles based on cell charger

2021 ◽  
Vol 12 (1) ◽  
pp. 385
Author(s):  
Amin Amin ◽  
Alexander Christantho Budiman ◽  
Sunarto Kaleg ◽  
Sudirja Sudirja ◽  
Abdul Hapid
Keyword(s):  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Negative Effects ◽  
Battery Cell ◽  
Active Balancing ◽  
A Cell ◽  
The Difference ◽  
Lifepo4 Battery ◽  
The Cost

Cell imbalance can cause negative effects such as early stopping of the battery charging and discharging process which can reduce its capacity. In the previous active balancing research, the energy used for the balancing process was taken from the cell or battery pack, resulting in drop of electric vehicle driving range. In this paper, a cell charger based battery balancing system is proposed with a reduction in the number of switches. The use of a cell charger aims to increase the usable energy of the battery pack, since the energy used for the balancing process is taken directly from the grid. The use of fewer switches aims to reduce the cost and space used on the battery management system (BMS) hardware. The charger used for the balancing process has a maximum current of 3 A and a maximum voltage of 3.65 V while the number of switches used is n+5 for n batteries. A 15S1P 200 Ah LiFePO4 battery pack consists of 15 cells used for testing purpose. The test results show that the time needed to equalize the 15 cell battery voltage reaches 6 hours from the difference between the highest and lowest battery cell voltages of 145.1 mV to 15.1 mV.

scholarly journals Smart Battery Pack for Electric Vehicles Based on Active Balancing with Wireless Communication Feedback

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3862 ◽  
Author(s):  
Mattia Ricco ◽  
Jinhao Meng ◽  
Tudor Gherman ◽  
Gabriele Grandi ◽  
Remus Teodorescu
Keyword(s):  
Life Cycle ◽  
Electric Vehicle ◽  
Electric Vehicles ◽  
Fault Tolerant ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Battery Cell ◽  
Active Balancing ◽  
Battery Cells

In this paper, the concept of smart battery pack is introduced. The smart battery pack is based on wireless feedback from individual battery cells and is capable to be applied to electric vehicle applications. The proposed solution increases the usable capacity and prolongs the life cycle of the batteries by directly integrating the battery management system in the battery pack. The battery cells are connected through half-bridge chopper circuits, which allow either the insertion or the bypass of a single cell depending on the current states of charge. This consequently leads to the balancing of the whole pack during both the typical charging and discharging time of an electric vehicle and enables the fault-tolerant operation of the pack. A wireless feedback for implementing the balancing method is proposed. This solution reduces the need for cabling and simplifies the assembling of the battery pack, making also possible a direct off-board diagnosis. The paper validates the proposed smart battery pack and the wireless feedback through simulations and experimental results by adopting a battery cell emulator.

scholarly journals Development of Life-cycle Detection and Extending Function for Reusing Automotive Lithium-ion Battery – Verified in 52V LiMnNiCoO2 Platform

2020 ◽  
Author(s):  
Wu-Yang Sean ◽  
Ana Pacheco
Keyword(s):  
Life Cycle ◽  
Lithium Ion Battery ◽  
Management System ◽  
Open Circuit Voltage ◽  
Lithium Ion ◽  
Open Circuit ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Cycle Detection

Abstract For reusing automotive lithium-ion battery, an in-house battery management system is developed. To overcome the issues of life cycle and capacity of reused battery, an online function of estimating battery’s internal resistance and open-circuit voltage based on adaptive control theory are applied for monitoring life cycle and remained capacity of battery pack simultaneously. Furthermore, ultracapacitor is integrated in management system for sharing peak current to prolong life span of reused battery pack. The discharging ratio of ultracapacitor is adjusted manually under Pulse-Width-Modulation signal in battery management system. In case study in 52V LiMnNiCoO2 platform, results of estimated open-circuit voltage and internal resistances converge into stable values within 600(s). These two parameters provide precise estimation for electrical capacity and life cycle. It also shows constrained voltage drop both in the cases of 25% to 75% of ultracapacitors discharging ratio compared with single battery. Consequently, the Life-cycle detection and extending functions integrated in battery management system as a total solution for reused battery are established and verified.

scholarly journals Application Error Analysis of SOC Estimation of Pure Electric Vehicles Based on Kalman Signal Big Data Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhaona Lu ◽  
Junlong Wang ◽  
Chuanxing Wang ◽  
Guoqing Li
Keyword(s):  
Electric Vehicles ◽  
Time Integration ◽  
Estimation Method ◽  
Open Circuit ◽  
Battery Pack ◽  
Estimation Accuracy ◽  
Battery Management System ◽  
Battery Management ◽  
Current Time ◽  
Power Battery

The state of charge estimation of a pure electric vehicle power battery pack is one of the important contents of the battery management system. Improving the estimation accuracy of the battery pack’s SOC is conducive to giving full play to its performance and preventing overcharge and discharge of a single battery. At present, the open-circuit voltage ampere-hour integral method is traditionally used to estimate the SOC value of the battery pack; however, this estimation method is not accurate enough to correct the initial value of SOC and cannot solve the problem of current time integration error between this correction and the next correction. As for the battery performance and characteristics of electric vehicles, it is pointed out that the size of the model value will affect the estimation accuracy of the Kalman signal value. Based on the analysis of the factors to be referred to in the calculation and estimation of SOC by Kalman for pure electric vehicles, the scheme is improved considering the change of battery model value, and the Kalman scheme is proposed. The feasibility and accuracy of the scheme are proved by several battery simulation experiments.

scholarly journals Lithium-Ion Battery Cell-Balancing Algorithm for Battery Management System Based on Real-Time Outlier Detection

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Changhao Piao ◽  
Zhaoguang Wang ◽  
Ju Cao ◽  
Wei Zhang ◽  
Sheng Lu
Keyword(s):  
Lithium Ion Battery ◽  
Outlier Detection ◽  
Management System ◽  
Lithium Ion ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Battery Cell ◽  
Online Clustering ◽  
Cell Balancing

A novel cell-balancing algorithm which was used for cell balancing of battery management system (BMS) was proposed in this paper. Cell balancing algorithm is a key technology for lithium-ion battery pack in the electric vehicle field. The distance-based outlier detection algorithm adopted two characteristic parameters (voltage and state of charge) to calculate each cell’s abnormal value and then identified the unbalanced cells. The abnormal and normal type of battery cells were acquired by online clustering strategy and bleeding circuits (R= 33 ohm) were used to balance the abnormal cells. The simulation results showed that with the proposed balancing algorithm, the usable capacity of the battery pack increased by 0.614 Ah (9.5%) compared to that without balancing.

scholarly journals Battery management system implementation with the passive control method using MOSFET as a load

2019 ◽  
Vol 53 (1-2) ◽  
pp. 205-213 ◽  
Author(s):  
Sinan Kıvrak ◽  
Tolga Özer ◽  
Yüksel Oğuz ◽  
Emre Burak Erken
Keyword(s):  
Management System ◽  
Passive Control ◽  
Control Method ◽  
Lithium Ion ◽  
Buck Converter ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Digital To Analog Converter ◽  
Battery Cells

In this study, a battery management system was implemented using the passive charge balancing method. The battery system was created with lithium ion battery cells commonly used in electric vehicles. Two main microprocessors were used as a master and slave for the management system. An STM32f103C8 microcontroller was used as a master, and a PIC18f4520 microcontroller was used as slave control units in the battery management system. Charge control of a battery pack consisting of four cells was performed. The information received from the current and voltage sensors was collected from each cell using a slave controller and sent smoothly to the master controller system. These experimental results indicated that the passive balancing method was implemented and the battery cells were charged successfully. The proposed method was applied to battery pack consisting of a four-cell LiFePO4 battery with a capacity of 40 Ah. This work incorporated original situation that have not been realized before. A digital to analog converter circuit was created using a buck converter topology. Thus, the MOSFET was used as an adjustable resistance. Also, it was one of the first studies in which the MOSFET was used as a regulated resistor in battery management systems.

scholarly journals A Critical Review on Lightweight Design of Battery Pack Enclosure for Electric Vehicles

2021 ◽  
Vol 4 (2) ◽  
pp. 53-62
Author(s):  
Ashvin Dhoke ◽  
◽  
Amol Dalavi
Keyword(s):  
Design Optimization ◽  
Electric Vehicle ◽  
Lightweight Design ◽  
Dynamic Performance ◽  
Primary Source ◽  
Battery Pack ◽  
Optimization Approach ◽  
Battery Management System ◽  
Battery Management ◽  
Battery Cell

An electric vehicle battery pack which is a gathering of battery modules which subsequently comprised of the battery cell is a primary source of control transmission for an Electric Vehicle (EV). The inappropriate design of the battery enclosure will cause many genuine issues, such as cracking, causing noise, or battery harm. At the same time, the weight of the battery enclosure is huge; in order to get better the driving range of the electric vehicle and diminish the influence of the battery on the vehicle dynamic performance and acceleration performance, it is essential to carry out the lightweight design of the battery enclosure. This paper reviews the multi-material battery enclosure design optimization, the multi- technologies, and a proficient Battery Management System (BMS) for compact battery pack design used to lightweight battery pack enclosure design; the multi-objective optimization approach for distinctive parameters of battery pack enclosure design optimization by diverse manufacturing techniques.

scholarly journals Estimation of State of Charge (SoC) Using Modified Coulomb Counting Method With Open Circuit Compensation For Battery Management System (BMS)

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Puspita Ningrum ◽  
Novie Ayub Windarko ◽  
Suhariningsih Suhariningsih
Keyword(s):  
Management System ◽  
Voltage Divider ◽  
Open Circuit ◽  
Voltage Sensor ◽  
State Of Charge ◽  
Battery Management System ◽  
Battery Management ◽  
Li Ion Battery ◽  
Control Center ◽  
Li Ion

Abstract— Battery is one of the important components in the development of renewable energy technology. This paper presents a method for estimating the State of Charge (SoC) for a 4Ah Li-ion battery. State of Charge (SoC) is the status of the capacity in the battery in the form of a percentage which makes it easier to monitor the battery during use. Coulomb calculations are widely used, but this method still contains errors during integration. In this paper, SoC measurement using Open Circuit Voltage Compensation is used for the determination of the initial SoC, so that the initial SoC reading is more precise, because if the initial SoC reading only uses a voltage sensor, the initial SoC reading is less precise which affects the next n second SoC reading. In this paper, we present a battery management system design or commonly known as BMS (Battery Management System) which focuses on the monitoring function. BMS uses a voltage sensor in the form of a voltage divider circuit and an ACS 712 current sensor to send information about the battery condition to the microcontroller as the control center. Besides, BMS is equipped with a protection relay to protect the battery. The estimation results of the 12volt 4Ah Li-ion battery SoC with the actual reading show an error of less than 1%.Keywords—Battery Management System, Modified Coulomb Counting, State of Charge.

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