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Showing 3 results for Lithium-Ion Battery
Volume 14, Issue 1 (5-2014)
Abstract
Active techniques based on the switched-capacitor converters (SCCs) are used in recent years widely for battery cell balancing applications, due to lack of bulky magnetic components. In addition, these converters are easily be integrated to reduce the volume. Despite of all these benefits, SCCs have some disadvantages such as number of active switches, currents spikes, low balancing speed, and high switching losses. In this paper, a chain resonant SCC is analyzed which can realize soft switching under the ZCS conditions to eliminate currents spikes to overcome the aforementioned SCCs drawbacks. Also, it has been modified to increase balancing speed of the Lithium-Ion battery cells. Then, a chain resonant SCC for balancing a combination of three battery cells with capacity of 2150 mAh and nominal voltage of 3.6 V has been simulated by MATLAB/SIMULINK and it has been implemented at 50 kHz to confirm operation of the converter. The simulation and experimental results are in good agreement with the given mathematical analyses and illustrate that the balancing speed has been improved more than three-fold, as compared with the conventional converter.
M. Nouri Khajavi, Gh.r. Bayat ,
Volume 19, Issue 1 (1-2019)
Abstract
An accurate estimation of the state of charge is necessary not only for optimal management of the energy in the electric vehicles (EV) and smart grids, but also to protect the battery from going to the deep discharge or overcharge conditions that degrades battery life and may create potentially dangerous situations like explosion. Despite the importance of this parameter, the state of charge cannot be measured directly from the battery terminals. In this research, an electric equivalent circuit model is simulated in the Simulink environment with two RC networks. This model has the advantage of providing a quick test for the extraction of parameters and dynamic characteristics of the battery model, but is not suitable for on-line applications in an EV. This is why algorithms need to be developed to estimate the SOC of the battery pack and the individual cells based on the measured data of each one. In this paper, for the validation of the neural network, a discharge rate of 0.6A and in the adaptive neuro fuzzy inference system (ANFIS) network, the discharge rate of 0.8, 0.1, and 0.45 was used. The comparison of ANFIS method with the neural method in this study showed that the ANFIS method is more accurate in estimating the state of charge and correlates the experimental points and the output of the network , so that ANFIS error in some states of charge is less than 2%.
Atieh Alihosseini, Maziar Shafaee, Saeed Ghasemian,
Volume 22, Issue 11 (11-2022)
Abstract
One of the main problems in the commercial use of lithium-ion batteries for high energy consumption is the heat problems associated with these batteries. Since many batteries are used together in order to generate higher power, it is important to predict their thermal performance. In this study, a heat management system of a lithium-ion battery equipped with a heat pipe is investigated. For this purpose, a part of a battery pack consisting of two batteries and a heat pipe is selected and its performance is experimentally investigated. These tests are performed at various ambient temperatures through a made test chamber with the ability to accurately control temperature. The experimental results show that although with increasing ambient temperature, the battery surface temperature increases, but due to the decrease in thermal resistance of the heat pipe, the effect of this temperature rise can be moderated and work as an active method. In addition, using forced convection in the condenser section, not only can the battery surface temperature be controlled below 40 ˚C, but it also distributes the temperature uniformly over the battery surface. The use of the heat pipe also helps to maintain more stable temperature conditions with lower temperature fluctuations in consecutive battery cycles.
