Novel methods for estimating lithium-ion battery state of energy and maximum available energy

Abstract

h i g h l i g h t sStudy on temperature, current, aging dependencies of maximum available energy. Study on the various factors dependencies of relationships between SOE and SOC. A quantitative relationship between SOE and SOC is proposed for SOE estimation. Estimate maximum available energy by means of moving-window energy-integral. The robustness and feasibility of the proposed approaches are systematic evaluated. Keywords: Battery management system (BMS) State of energy (SOE) State of charge (SOC) Maximum available energy a b s t r a c tThe battery state of energy (SOE) allows a direct determination of the ratio between the remaining and maximum available energy of a battery, which is critical for energy optimization and management in energy storage systems. In this paper, the ambient temperature, battery discharge/charge current rate and cell aging level dependencies of battery maximum available energy and SOE are comprehensively analyzed. An explicit quantitative relationship between SOE and state of charge (SOC) for LiMn 2 O 4 battery cells is proposed for SOE estimation, and a moving-window energy-integral technique is incorporated to estimate battery maximum available energy. Experimental results show that the proposed approaches can estimate battery maximum available energy and SOE with high precision. The robustness of the proposed approaches against various operation conditions and cell aging levels is systematically evaluated.

Intelligent optimization methodology of battery pack for electric vehicles: A multidisciplinary perspective

“…Zheng et al comprehensively analyzed the dependence of the battery's maximum available energy on the ambient temperature, charge/discharge current rate and battery aging degree dependence, and combined energy integration technology to estimate the maximum available battery energy. The maximum available energy of the battery improved the battery balancing effect, but this method was too costly and difficult to apply in actual engineering 59 . Considering the criteria of uniformity and equalization in the battery manufacturing and assembly process, the problem of uneven temperature distribution and capacity attenuation of the battery module can be effectively avoided, thereby improving the service life and safety level of the battery module 13,60 …”

Optimal Sizing Procedure for Electric Vehicle Supply Infrastructure Based on DC Microgrid with Station Commitment

“…The behavior of ESSs is characterized by the energy amount present in the storage device in each time step. However, a high degree of correspondence is observed between energy amount and state-of-charge (SOC), given by the levels of current [33]. The assumption of discarding voltage variations in this procedure further leads to the exploitation of SOC in each time step E i,s,t to define ESS availability in the operation planning [25].…”

A Remaining Discharge Energy Prediction Method for Lithium-Ion Battery Pack Considering SOC and Parameter Inconsistency

“…To make them comparable, the coefficient of variation (CV) is used to characterize the DOI. The CV is a standardized measure for the dispersion of a probability distribution, which is defined as the ratio of the value of standard deviation, σ, to the mean, µ, (or its absolute value, |µ|), as shown in Equation (9). The advantage of the CV is that the effects of the dimension and average can be eliminated, so that different parameters' DOIs can be compared directly.…”