Electrifying Transportation with Julia
2019-07-25, 17:25–17:35, Elm A

In this talk, we will discuss implementation of various models relevant for electrochemical energy systems in order to more rapidly optimize component design and use-case specific optimization.We will show massive performance improvements gained through Julia for a variety of popularpseudo-2D porous electrode models describing Li-ion batteries. In addition, we will illustrate an example of an integrated design workflow of an aircraft power dynamics model along with a battery model, implemented within Julia.

Modeling electric vehicle systems and their batteries helps to hasten the adoption and development of electric vehicles by clarifying their capabilities and requirements. Much progress has been made in electrifying automobiles, but less has been made in aircraft, which contribute a significant fraction of the greenhouse gas emissions from transportation. Aircraft have different battery requirements than automobiles and other modes of ground transportation. Specifically, the take-off and climb stages of flight can require discharge rates far greater than ground based systems.To study the effects of electrifying aviation, models of aircraft and batteries need to be integrated and studied together. It is essential to calculate the parameters of both the aircraft and the battery because these two systems are dependent on each other.We use Julia to model both aircraft and batteries. To model aircraft, a physics based performance model is used to calculate the energy and power requirements of the system. We use historical aircraft of various size and configurations to calculate energy and power requirements of different classes of aircraft. Our lab has modeled both eVTOL and conventional aircraft. Convert-ing the model from MATLAB to Julia yielded a massive speedup, enabling us to test many more configurations and classes of aircraft.We use several battery models depending on the size and battery requirements of the mode of transportation. For modes of that are capable of being powered by Lithium-Ion batteries, we use psuedo-2D single particle models incorporating all relevant properties of batteries, including energy, discharge rates, mass, and temperature. These models involve large systems of differential equations which can be efficiently solved using the DifferentialEquations.jl package. Porting these battery models to Julia yielded massive speedups, enabling parameter sweeps and use-case specific optimization of battery cell parameters. Larger and longer range forms of transportation have battery requirements that exceed what can be provided by Lithium-Ion batteries. For example,a fully electric commercial aircraft could require a Lithium Air battery. We also use the speed provided by Julia to increase our modeling capabilities for these forms of transportation. In thistalk, we will show an integrated model of a Lithium Air battery and an aircraft performance model.


Shashank Sripad