Charging of electric vehicles

Smarter charging is key to electromobility

​For electric vehicles to be implemented on a large ​scale, smart solutions for charging are required. Currently, development of digital systems is under way that in real time will control and distribute the available power, depending on such factors as how much each driver is prepared to pay, and how fast the vehicle must be fully charged for the next trip.
Lang TongDuring nine months, Chalmers University of Technology is reinforced by Professor Lang Tong from Cornell University, USA. As a guest professor, one of his tasks will be to contribute to Chalmers' research in the field of electric power engineering, primarily focusing on digitalization in large-scale infrastructure for the charging of electric vehicles.

“Being a researcher interested in electromobility, Chalmers is an attractive place to visit”, says Lang Tong. “The close relation to industry as well as Chalmers' often application-driven research on electrified vehicles are interesting to me. In return, I hope to be able to contribute with my knowledge of applying ideas from artificial intelligence and data science in power and energy systems.”

Lang Tong was in 2018 awarded the prestigious Fulbright Distinguished Chair in Alternative Energy Technology. His visit to Chalmers is funded by the Fulbright Scholar Program, a bi-national organization promoting exchange between Sweden and the US with government funding from both nations.

Developing smart charging of electrified vehicles
He is currently engaged in a collaborative research project at the department of Electrical Engineering aiming at developing technology and software systems for smart charging of electrified vehicles.

“In 12-14 years, the proportion of electric cars is forecasted to increase to about 10 percent of the vehicle fleet”, Lang Tong says. “The infrastructure for charging the vehicles must, by then, be upgraded to become sufficient and robust enough to handle the increasing demand. Otherwise the lack of infrastructure risks hampering the development.”

What will happen if thousands of drivers in Gothenburg, when they get home from work in the evening, plug in their electric cars for charging at the same time?

“Well, it won´t be possible to charge all those vehicles at the same time”, Lang Tong notes. “The local distribution network will get overloaded; the power demand will be too heavy.”

Instead, the solution lies in applying digital systems that in real time control and distribute the available power depending on the demand. 

“To match supply and demand of energy the development of smart systems is required. The systems need to be so smart that they also can take into account such factors as how much each driver is prepared to pay, and how fast the vehicles must be fully charged for the next trip.”

At times, when there is a high strain on the grid from prioritized electrical equipment, the charging of some vehicles could be planned to be conducted later. Or the stored energy in the batteries of the car could even be used as a reinforcement or backup to the grid.

The potential of digitalization
“I am very pleased with the help Lang Tong gives us to grasp the new possibilities and to develop the use of data science and artificial intelligence in our research and in our education of power engineers for the future,” says Jörgen Blennow, Head of division Electric Power Engineering. “Digitalization will emerge in more and more areas, and it is important for us to fully understand what that means in terms of reliability, controllability and optimization of power systems.”

During his stay at Chalmers, Professor Lang Tong also will be giving courses on machine learning and artificial intelligence in power systems to doctoral students.

A sustainable approach to future power systems
“In Scandinavia, I experience that there are strong environmental concerns against the use of fossil fuels, which in turn support the development of more sustainable solutions for transportation, generation of electricity and heating”, Lang Tong says. “However, for the electrified transportation system to be expanded on a large scale, there is also a need for political long-term policies and incentives supporting electrification, along with the expansion of infrastructure for charging the vehicles.”

“The current power system is going through a transformation”, he continues. “In my opinion, this development is driven by two technological areas that require the attention of the researchers of today. On one hand, there is the development of electromobility. On the other hand, there is the need of an expanded system for solar energy combined with batteries to store the energy. A new power system design will make it possible for people to produce their own energy, in a small scale at home, and to save surplus electricity for later.” 

If electricity does not necessarily need to be produced at the same time as it is consumed, to maintain the balance in the electrical grid, conditions are created for more producers to enter the system, while a higher share of renewable energy sources also can be introduced.

Visiting together
Professor Lang Tong and his wife, Professor Qing Zhao also from Cornell University, have accompanied each other to Sweden and Chalmers. Both are visiting professors at the department of Electrical Engineering, Qing Zhao being a Jubilee Professor of Chalmers 2019.​ 

“Indeed, this was a good opportunity for us both to come to Chalmers and Gothenburg. We like the city, not least we enjoy shopping fresh food in the local market.”

Before Lang Tong leaves Sweden, he would like to visit some more parts of the country. Accompanied by family and friends, he took a trip to Lapland during the winter season to experience the climate and the culture up north.

Text and photo: Yvonne Jonsson​

For more information, please contact:
Lang Tong, guest professor from Cornell University, USA
Jörgen Blennow​, head of division Electric Power Engineering, department of Electrical Engineering, Chalmers University of Technology

Published: Tue 16 Apr 2019. Modified: Thu 02 May 2019