scholarly journals A Non-Dissipative Equalizer with Fast Energy Transfer Based on Adaptive Balancing Current Control

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1990
Author(s):  
Shun-Chung Wang ◽  
Chun-Yu Liu ◽  
Yi-Hua Liu
Keyword(s):  
Energy Transfer ◽  
Duty Cycle ◽  
Nonlinear Behavior ◽  
Lithium Ion ◽  
Current Control ◽  
Test Results ◽  
Voltage Difference ◽  
Battery Packs ◽  
Circuit Component ◽  
Transfer Stage

In this study, an active inductive equalizer with fast energy transfer based on adaptive balancing current control is proposed to rapidly equilibrate lithium-ion battery packs. A multiphase structure of equalizer formed by many specific parallel converter legs (PCLs) with bidirectional energy conversion serves as the power transfer stage to make the charge shuttle back and forth between the cell and sub-pack or sub-pack and sub-pack more flexible and efficient. This article focuses on dealing with the problem of slow balancing rate, which inherently arises from the reduction of balancing current as the voltage difference between the cells or sub-packs decreases, especially in the later period of equalization. An adaptive varied-duty-cycle (AVDC) algorithm is put forward here to accelerate the balance process. The devised method has taken the battery nonlinear behavior and the nonideality of circuit component into consideration and can adaptively modulate the duty cycle with the change of voltage differences to maintain balancing current nearly constant in the whole equilibrating procedure. Test results derived from simulations and experiments are provided to demonstrate the validity and effectiveness of the equalizer prototype constructed. Comparing with the conventional fixed duty cycle (FDC) method, the improvements of 68.3% and 8.3% in terms of balance time and efficiency have been achieved.

scholarly journals Optimization of Liquid Cooling and Heat Dissipation System of Lithium-ion Battery Packs of Automobile

2021 ◽  
pp. 101012
Author(s):  
Huanwei Xu ◽  
Xin Zhang ◽  
Ge Xiang ◽  
Hao Li
Keyword(s):  
Lithium Ion Battery ◽  
Heat Dissipation ◽  
Lithium Ion ◽  
Liquid Cooling ◽  
Battery Packs ◽  
Dissipation System

Enhancing thermal safety in lithium-ion battery packs through parallel cell ‘current dumping’ mitigation

2021 ◽  
Vol 286 ◽  
pp. 116495
Author(s):  
Samuel T. Plunkett ◽  
Chengxiu Chen ◽  
Ramin Rojaee ◽  
Patrick Doherty ◽  
Yun Sik Oh ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Lithium Ion ◽  
Thermal Safety ◽  
Battery Packs ◽  
Cell Current

scholarly journals A Control Method for IPMSM Based on Active Disturbance Rejection Control and Model Predictive Control

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 760
Author(s):  
Fang Liu ◽  
Haotian Li ◽  
Ling Liu ◽  
Runmin Zou ◽  
Kangzhi Liu
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Duty Cycle ◽  
Control Strategy ◽  
Disturbance Rejection ◽  
Torque Ripple ◽  
Current Control ◽  
Active Disturbance Rejection Control ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

In this paper, the speed tracking problem of the interior permanent magnet synchronous motor (IPMSM) of an electric vehicle is studied. A cascade speed control strategy based on active disturbance rejection control (ADRC) and a current control strategy based on improved duty cycle finite control set model predictive control (FCSMPC) are proposed, both of which can reduce torque ripple and current ripple as well as the computational burden. First of all, in the linearization process, some nonlinear terms are added into the control signal for voltage compensation, which can reduce the order of the prediction model. Then, the dq-axis currents are selected by maximum torque per ampere (MTPA). Six virtual vectors are employed to FCSMPC, and a novel way to calculate the duty cycle is adopted. Finally, the simulation results show the validity and superiority of the proposed method.

scholarly journals Impact of Relaxation Time on Electrochemical Impedance Spectroscopy Characterization of the Most Common Lithium Battery Technologies—Experimental Study and Chemistry-Neutral Modeling

2021 ◽  
Vol 12 (2) ◽  
pp. 77
Author(s):  
Md Sazzad Hosen ◽  
Rahul Gopalakrishnan ◽  
Theodoros Kalogiannis ◽  
Joris Jaguemont ◽  
Joeri Van Mierlo ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Impedance Measurement ◽  
Nonlinear Behavior ◽  
Lithium Ion ◽  
Health Condition ◽  
Battery Cell ◽  
Rest Time

In electrified vehicle applications, understanding the battery characteristics is of great importance as it is the state-of-art principal energy source. The key battery parameters can be identified by one of the robust and nondestructive characterization techniques, such as electrochemical impedance spectroscopy (EIS). However, relaxing the battery cell before performing the EIS method is crucial for the characterization results to be standardized. In this study, the three most common and commercially available lithium-ion technologies (NMC/graphite, LFP/graphite, NCA/LTO) are investigated at 15–45 °C temperature, in the range of 20–80% state of charge (SoC) and in fresh and aged state of health (SoH) conditions. The analysis shows that the duration of the relaxation time before impedance measurement has an impact on the battery’s nonlinear behavior. A rest time of 2 h can be proposed, irrespective of battery health condition, considering neutral technology-based impedance measurement. An impedance growth in ohmic and charge transfer characteristics was found, due to aging, and the effect of rest periods was also analyzed from an electrochemical standpoint. This experimental data was fitted to develop an empirical model, which can predict the nonlinear dynamics of lithium technologies with a 4–8% relative error for longer rest time.

A cell sorting Algorithm for series-parallel configured Lithium ion battery packs in spacecrafts

2020 ◽  
Author(s):  
Ananda S ◽  
Lakshminarasamma N ◽  
Radhakrishna V ◽  
Pramod M ◽  
Srinivasan M S ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Cell Sorting ◽  
Lithium Ion ◽  
Sorting Algorithm ◽  
Battery Packs ◽  
A Cell

The New Measurement and Calculation Method for Dynamic Parameters of DC Motor Based on dSPACE System

2012 ◽  
Vol 562-564 ◽  
pp. 1496-1500
Author(s):  
Qiang Li ◽  
Wei Chen ◽  
Ren He
Keyword(s):  
Mathematical Model ◽  
Duty Cycle ◽  
Calculation Method ◽  
Dc Motor ◽  
Control Algorithms ◽  
Dynamic Parameters ◽  
Hardware In The Loop ◽  
Test Results ◽  
Complex Control ◽  
Measurement And Calculation Method

To investigate the accuracy of modeling DC motor, the platform for measurement and calculation dynamic parameters is built by the Hardware-In-the-Loop(HIL) method based on dSPACE system. The running state of DC motor has to be changed with adjustment of PWM duty-cycle using ControlDesk software. Having got measurement and calculation parameters value of DC motor, we compare the test results with simulation value using the model of DC motor with cascade control in Matlab/Simulink software according to the classical mathematical model. It confirms the established model of DC motor accurately and reliability using new parameters, which provides the basis of more complex control algorithms and also indicates that the feasibility and generalization application value of measurement and calculation method for DC motor.

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