Three-Minute Thesis Competition 2015 - Faculty of Mathematics Heat, Sepideh Afshar
1,168 views · Published 1 April 2015 · 2:55 · Indexed 26 October 2026
Channel: uwaterloo · 2015 · Education
“State of Charge Estimation of a Battery” Hello everyone. I’m Sepideh from Applied Mathematics. And today I’m going to present my work on a state of charge estimation for batteries in hybrid electric vehicles. Well nowadays, hybrid electric vehicles are taking the place of gas engine vehicles. Hybrid electric vehicles have both gas engine and electric motor working together. It means that in addition to the gas tank, it should be also a source of electric energy. Batteries are the source of energy in hybrid electric vehicles. In order to provide a safe drive, both the amount of flow inside the gas tank and the level of electric energy must be defined in a drive cycle. As a driver of a gas engine vehicle, we know how important it is to know, or to check the state of gas during a trip. In hybrid electric vehicles, knowing the amount of electric energy is even more important. Now, here is a question. How can the level of electric energy be defined and measured for batteries? The answer is that, this level of energy is indicated by some quantity which is called state of charge. And state of charge is directly related to the available amount of charge inside the battery. Unfortunately, state of charge is not a measurable quantity. However, there are other quantities that can be measured, like voltage or current. So an algorithm is required to map the available measurements to the state of charge. A very simple example of this algorithm is the one which is used in your electric devices to show you what is the remaining charge in your electric device. However, estimating the state of charge is not easy for hybrid electric vehicles because of the severe working conditions. It means that a more sophisticated algorithm is required in which, in addition to the measurements, a prior knowledge or charging and discharging behavior is also employed. This knowledge is in terms of mathematical equations. And with the state of mathematical chemistry science, the equations can be derived such that the state of charge is a part of modelling. Now the objective of my project is to use advanced mathematics to design algorithms to estimate the state of charge using the mathematical equation in a real-time application. Thank you for listening.
