Analysis of the Current Electric Battery Models for Electric Vehicle Simulation

Abstract

Electric vehicles (EVs) are a promising technology to reduce emissions, but its development enormously depends on the technology used in batteries. Nowadays, batteries based on lithium-ion (Li-Ion) seems to be the most suitable for traction, especially nickel-manganese-cobalt (NMC) and nickel-cobalt-aluminum (NCA). An appropriate model of these batteries is fundamental for the simulation of several processes inside an EV, such as the state of charge (SoC) estimation, capacity and power fade analysis, lifetime calculus, or for developing control and optimization strategies. There are different models in the current literature, among which the electric equivalent circuits stand out, being the most appropriate model when performing real-time simulations. However, impedance models for battery diagnosis are considered very attractive. In this context, this paper compares and contrasts the different electrical equivalent circuit models, impedance models, and runtime models for battery-based EV applications, addressing their characteristics, advantages, disadvantages, and usual applications in the field of electromobility. In this sense, this paper serves as a reference for the scientific community focused on the development of control and optimization strategies in the field of electric vehicles, since it facilitates the choice of the model that best suits the needs required.

Empirical Electrical and Degradation Model for Electric Vehicle Batteries

“…NCM cells provide better safety compared to NCA cells. In contrast, the cost of NCA cells is lower [38], [55]. [57].…”

“…Generally, they only consider the main variables and parameters, neglecting others that have less influence on the main effects to be modeled. ECMs are widely used in battery management systems (BMSs) [38] for their capability to operate on few parameters and low computational speed with sufficient precision [39]. Their parameters can be determined by combining them with electrochemical or EIS models or by other techniques generally based on experimental tests.…”

“…Aging experimental studies are time intensive and only focus on certain discrete aging conditions (temperature, DoD, and so on). Therefore, they do not provide a complete understanding of the entire range of conditions [10], [38]. Furthermore, a model with physical correspondence is required to be applicable in a vehicle, making models in the frequency domain unsuitable for this purpose [37].…”

Battery Models for Battery Powered Applications: A Comparative Study

“…These kinds of batteries are used for both stationary and mobile applications because of their high-energy density and high-power density. Great performances and innovative designs are asked for by the electric transportation market [1]; for this reason, accurate and reliable models are needed. Knowing SoC (State of Charge) [2,3], SoH (State of Health) [4], OCV (Open Circuit Voltage) [5], currents, and voltages is absolutely necessary in order to have well designed and efficient energy storage systems, because nonlinear physical effects in batteries strongly influence battery lifetime [6].…”

Commercial Electric Vehicle Battery Degradation modelling and charging assessing using a real driving cycle

“…These chemicals are nickel-manganese-cobalt (NMC) and nickel-cobaltaluminium, referred to the cathode material. Lithiumferrous-phosphate is not considered most appropriate due to its lower specific energy, though his specific power is greater [4].…”