Modeling and validation of lithium-ion battery with initial state of charge estimation

Abstract

The modeling of lithium-ion battery is an important element to the management of batteries in industrial applications. Various models have been studied and investigated, ranging from simple to complex. The second-order equivalent circuit model was studied and investigated since the dynamic behavior of the battery is fully characterized. The simulation model was built in Matlab Simulink using the Kirchhoff Laws principle in mathematical equations, while the battery's internal parameters were identified by using the BTS4000 (Battery tester) device. To estimate the full state of charge (SOC), the initial state of charge (SOC0) must be identified or measured. Hence, this paper seeks for the SOC estimation by using experimental terminal voltage data and SOC with Matlab lookup table. Then, the simulated terminal voltage, as well as the SOC of the battery are compared and validated against measured data. The maximum relative error of 0.015 V and 2% for terminal voltage and SOC respectively shows that the proposed model is accurate and relevant based on the error analysis.

State of charge estimation for lithium-ion batteries connected in series using two sigma point Kalman filters

“…Normally, we need to estimated SoC 𝑁 times for 𝑁 cells. If the number of cells 𝑁 is large, there is a large amount of calculation [18], [19]. To reduce the SoC estimation times, in this work we use only two SPKFs, the first filter estimates the mean of 𝑁 SoC and the current sensor bias, the second filter estimates 𝑁 SoC differences from the average SoC, the estimated SoC of each cell then is calculated by the sum of the average SoC determined by the first filter and the difference SoC estimated by the second filter.…”

“…This paper introduces the SoC estimation method for a LiB connected in series using sigma point Kalman filters (SPKF) to minimize the influence of current and vfoltage measurement noise on the estimated SoC results. By using the second-order equivalent circuit model (SECM), this allows to describe more exactly the cell's dynamic in the charged and discharged scenarios with amplitude varying suddenly (an important feature of electrical vehicles using LIBs must be considered) [19]. This method uses two SPKFs, the SoC of cells in the pack is calculated by sum of pack's average SoC estimated by first SPKF and SoC differences estimated by second SPKF.…”

Comprehensive analysis of current research trends in energy storage technologies

“…The technology behind the NiCd batteries is quite old and there has not been a recent breakthrough [41], [42]. Because of this toxicity, the NiCd batteries are replaced by NiMH batteries.…”

The different approach for supercapacitor modelling in the perspective of self-discharge study

“…The demand for energy storage increases over time along with the demand for renewable energy system and electric vehicles which both requires energy storage to store the energy and released the energy when required [1]. There are numerous types of energy storage that have been used now such as battery, supercapacitor and fuel cells [1], [2]. Supercapacitor (SC) is one of the energy storage types other than the battery.…”