Abstract:
Due to carbon emissions electric vehicles got popularity over fuel-based vehicles. Lithium-ion
batteries are widely used in Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) as a
storage technology because Lithium-ion batteries are significant solutions for storing sustainable
energy and especially interesting for green transportation. Since these batteries face limitation of
losses in power and energy capabilities at low-temperature operations. Also, voltage instability of
the batteries is a cause of power blackout it is needed to enhance voltage stability of batteries. Such
models in which thermal dynamics have a big impact on the battery’s performance (in terms of
active and passive resistance to output parameters) require the development of complex system
equations. The use of Bond Graph (BG) tool becomes effective and simple for attaining system
equation of systems which involve both electrical and thermal dynamics.
The Lithium-Ion batteries have different electric equivalent models and commonly used models
are Thevenin and Second-Order Battery. In this research the Bond graph technique is used to
understand and model complete battery packs of Thevenin and Second-Order Battery model of
Lithium-Ion batteries considering both electrical and thermal dynamics. Furthermore, state-space
equations of electro-thermal battery packs are computed to analyze model dynamics and responses.
In the end, models are synthesized with a PID controller in order to improve voltage stability and
get stabilized output voltage. Which resulted in obtaining stabilized voltage response and reduced
settling time.
