An improved Thevenin model of lithium-ion battery with high accuracy for electric vehicles

Ding, Xiaofeng; Zhang, Donghuai; Cheng, Jiawei; Wang, Binbin; Luk, P.C.K.

doi:10.1016/j.apenergy.2019.113615

Cited by 97 publications

(34 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main parameters of the test microgrid are shown in Table 2, and the structure of the proposed strategy in MATLAB/Simulink 2018b is shown in Figure 10. The important simulation setups include: (1) the control period is 5e −6 s; (2) the power disturbances can be imposed on the system by adding or reducing the load units; (3) the distributed generation systems are equivalent to a DC voltage source [41].…”

Section: Simulation Resultsmentioning

confidence: 99%

Microgrid Frequency Fluctuation Attenuation Using Improved Fuzzy Adaptive Damping-Based VSG Considering Dynamics and Allowable Deviation

Liang

Niu

2020

Energies

View full text Add to dashboard Cite

Recently, virtual synchronous generators (VSGS) are a hot topic in the area of microgrid control. However, the traditional fixed-parameter-based VSG control methods have an obvious disadvantage. Namely, if the damping value is set to be small, the amplitude of frequency deviations under external power disturbances is large, meaning that the frequency suppression capacity is insufficient, but if the damping value is large, the dynamics of the system will be greatly sacrificed. To solve the problem, taking the dynamic characteristics and the maximum allowable frequency deviation (MAFD) into account, in this paper an improved fuzzy adaptive damping-based VSG control strategy is proposed to simultaneously attenuate the microgrid frequency fluctuations and guarantee the system dynamics. Firstly, in order to address the necessity of using an adaptive damping-based VSG, the structure of a fixed-parameter VSG method that incorporates the f-p/Q-V droop controllers is introduced, based on which a small signal model is established to discuss the impacts of the virtual damping on the frequency response characteristics concerning the different penetration levels of power disturbances. Then, considering the dynamics and MAFD, a fuzzy adaptive controller is constructed relying on the well-designed membership functions, control rules and output scaling factors. The main feature of the improved fuzzy controller is that two alternative output scaling factors are employed to allow the system to be overdamped when the frequency deviation is large and undamped when the frequency deviation is small, balancing the frequency response dynamics and stability characteristics. To verify the effectiveness of the proposed fuzzy adaptive damping-based VSG technique, a computer simulation is conducted on a microgrid system in MATLAB/Simulink, and the obtained results are compared with the conventional droop control and fixed-parameter based VSGs. By using the proposed fuzzy adaptive damping-based VSG control method, the peak frequency deviations under the large power disturbances would become at least 8% lower compared to the traditional droop control and fixed-parameter VSG control, and meanwhile, the frequency response speed is fast when the disturbance stands at a low position. Consequently, it is valuable to promote the proposed techniques in engineering.

show abstract

Section: Simulation Resultsmentioning

confidence: 99%

Microgrid Frequency Fluctuation Attenuation Using Improved Fuzzy Adaptive Damping-Based VSG Considering Dynamics and Allowable Deviation

Liang

Niu

2020

Energies

View full text Add to dashboard Cite

show abstract

“…The equivalent circuit model is widely used in battery management systems to describe the dynamics of the battery due to its clear physical meaning and balance between computational accuracy and complexity [6,7,21]. Over the past decade, researchers have proposed many kinds of equivalent circuit models, such as the Rint model [22], Thevenin model [23], PNGV model [24], and GNL model [25]. Comparing the SOC estimation accuracy and robustness of the above different equivalent circuit models, Lai, Zheng and Sun [9] and Hu, et al [26] found that the estimation accuracy does not always improve with the increase of the capacitive resistance network.…”

Section: Lithium-ion Battery Modelingmentioning

confidence: 99%

A State of Charge Estimation Method of Lithium-Ion Battery Based on Fused Open Circuit Voltage Curve

et al. 2020

View full text Add to dashboard Cite

The open circuit voltage (OCV) and model parameters are critical reference variables for a lithium-ion battery management system estimating the state of charge (SOC) accurately. However, the polarization effect reduces the accuracy of the OCV test, and the model parameters coupled to the polarization voltage increase the non-linearity of the cell model, all challenging SOC estimation. This paper presents an OCV curve fusion method based on the incremental and low-current test. Fusing the incremental test results without polarization effect and the low current test results with non-linear characteristics of electrodes, the fusion method improves the OCV curve’s accuracy. In addition, we design a state observer with model parameters and SOC, and the unscented Kalman filter (UKF) method is employed for co-estimation of SOC and model parameters to eliminate the drift noise effects. The SOC estimation root mean square error (RMSE) of the proposed method achieves 0.99% and 1.67% in the pulse constant current test and dynamic discharge test, respectively. Experimental results and comparisons with other methods highlight the SOC estimation accuracy and robustness of the proposed method.

show abstract

“…The first-order Thevenin circuit is adopted as the battery model, in which a RC link that can describe the polarization of the battery is added to the Rint model consisting of only one constant voltage source and one resistor [36]. Compared with the more accurate PNGV model and Massimo Ceraolo model, it reduces the difficulty of parameter identification and accurately simulates the dynamic characteristics of the battery [37].…”

Section: Actuator Mathematical Modelingmentioning

confidence: 99%

Experimental Research on PMSM Ball Screw Actuator and Structural Design Suggestion of Featured Active Suspension

2020

View full text Add to dashboard Cite

Aiming to develop a practical active suspension, a PMSM ball screw actuator prototype is manufactured and experimented for parameter identification. Based on identification results, a new doublevibration-reduction-structure for the featured active suspension is proposed to cope with the problem caused by the actuator's overlarge equivalent inertial mass. Unlike using a resistance to absorb output energy of the actuator, a method of varying charge voltage in steps is utilized to reclaim vibration energy into the battery pack directly. The mechanical and energy-regenerative characteristics are tested for verification of the marked parameters and identification of the unmarked parameters, especially for the Coulomb damping and the equivalent inertial mass of the actuator prototype. Besides, a high energy-regenerative efficiency and a large capability of electromagnetic control force are achieved, the overlarge equivalent inertial mass exists. To reduce the amplified demand of the active control force caused by the actuator's overlarge equivalent inertial mass directly exposed to the unsprung mass acceleration, the new double-vibration-reductionstructure (DVRS) based active suspension structure scheme suggestion with an added-vibration-reductionstructure (AVRS) between the actuator and the unsprung mass is proposed. Regulated by the corresponding LQG controller, the proposed active suspension can achieve almost the same performance of the conventional ideal active suspension.

show abstract

An improved Thevenin model of lithium-ion battery with high accuracy for electric vehicles

Cited by 97 publications

References 18 publications

Microgrid Frequency Fluctuation Attenuation Using Improved Fuzzy Adaptive Damping-Based VSG Considering Dynamics and Allowable Deviation

Microgrid Frequency Fluctuation Attenuation Using Improved Fuzzy Adaptive Damping-Based VSG Considering Dynamics and Allowable Deviation

A State of Charge Estimation Method of Lithium-Ion Battery Based on Fused Open Circuit Voltage Curve

Experimental Research on PMSM Ball Screw Actuator and Structural Design Suggestion of Featured Active Suspension

Contact Info

Product

Resources

About