Reconciling the grid and EV charging infrastructure - Embedded.com

Reconciling the grid and EV charging infrastructure

Dynamic charging is one of the methods that can increase the availability of charging infrastructure while also protecting the grid.

The world is moving toward electric mobility, which involves the decarbonization of the entire transportation system through the mass adoption of electric vehicles. As demand for EVs rises, we must face the consequences that this increasing number of vehicles will have on the electric infrastructure — that is, the power grid. A large number of EVs will indeed increase the power demand required for charging, with a potential risk of overstressing the grid past its capacity.

While some believe that EVs would overburden the power grid, others have discovered ways to support our energy infrastructure, such as wireless charging, vehicle-to-grid integration, and more efficient ways of utilizing renewable energy sources, to mention a few. It is not easy to quantify the additional demand for electricity, which wide adoption of EVs will take with it. Which types of vehicles will be charged (passenger or medium-/heavy-duty fleets), when, and how many of them will be charged are all factors affecting power demand.

Because the charging infrastructure is far from having a widespread distribution throughout the territory, engineers have started exploring alternative charging options other than the conventional and traditional stationary charging station. The proposed solution should have a twofold objective: to reduce the charging time as much as possible compared with the static solution and to not compromise the use of the power grid.

Electreon wireless charging solution

Among the solutions already able to accelerate the availability of the charging infrastructure while simultaneously protecting the grid is dynamic charging, also known as wireless or in-motion charging.

ElectReon, a leading company in the development of wireless charging technology on the road of commercial EVs, for public transport and passengers, has developed a solution capable of charging EVs wirelessly, both dynamically (while they are in motion) and static (while they are stationary).

“ElectReon has been dealing with wireless charging for nine years,” said Oren Ezer, co-founder and CEO of ElectReon. “We decided to think about a better way to reduce the size of the battery, and this is why we started to investigate and explore wireless charging. Today, I believe that we are the leading company in dynamic wireless charging technology.”

Wireless dynamic charging (or in-motion charging, as ElectReon calls it) differs from semi-dynamic charging, mainly used for taxis and last-mile delivery, and from the more traditional (and for some aspects, less challenging) static charging, wherein there is no motion at all.

“With dynamic charging, the vehicle is driving, so we need to control the system in a way that we will be able to identify the vehicle and to control and activate the energy transfer,” said Ezer. “It is a very complex system. Just think about the communication that is needed between the coil inside the vehicle and the system outside of it. I think that today, we are almost the only company that can provide dynamic charging.”

The impact on the environment, as well as on the landscape, is almost nothing, as the system is deployed underground. As shown in Figure 1, the coils are buried under the asphalt, while the management unit (the “brain” of the system) is outside the road.


Figure 1: Close-up of the coils during installation

Vehicle identification is a major task of this system, as, for safety reasons, it shall not be activated when there is no vehicle. Once identification has succeeded, the system shall interact with the billing which will be onboard, unlike the static charging system that is outside of the vehicle.

According to ElectReon, in the future, we will see only wireless charging solutions because of their several benefits, including the price. With wireless charging, there is no visual impact, as the coils are installed underground. That means the solution can be deployed on the roads and on the driving streets of any city, without ruining the landscape with cables and poles. Wireless charging can also be deployed in locations where conventional corded (plug-in) charging solutions cannot, such as under taxi queues and at bus stations and terminals.

Other benefits of dynamic charging include the potential integration with renewable energy sources (solar or wind), thus reducing the need for additional energy storage devices and enabling a more even distribution of the power demand during the day.

“What we are doing at ElectReon is focusing on fleets like public-transportation buses and taxis,” said Ezer. “Taxis have to stop their operation during the day in order to charge batteries, and so they need a proper solution. We believe that wireless charging can give them a solution.”

Besides buses (see Figure 2), ElectReon is also focusing on last-mile delivery trucks, especially when they drive inside cities and need a solution to electrify their loading dock. That also applies to long-haul trucks that drive from point to point in fixed routes, like taking goods from a port and moving them to a hub.


Figure 2: An electric bus combined with ElectReon’s dynamic charging system

“We believe that, for medium- and heavy-load trucks, dynamic charging is the only solution instead of carrying multiple, heavy, and bulky batteries,” said Ezer.

Regarding power levels, ElectReon’s solution can provide 11 kW for passenger vehicles, while for heavy-duty vehicles or buses, the charging power rises to 75 kW. Both these values are almost identical to the ones provided by a conductive solution.

According to Ezer, charging is something that is related not just to power but to time and space. This means that if we have more time for charging, we can reduce or lower the amount of energy, so we don’t need a huge connection to the grid. That also means the size of the battery can be reduced, resulting in lighter and more efficient vehicles.

“We can help the grid handle the huge power demand, which will come with the electrification of the transportation system,” said Ezer. “We are enabling lighter and cheaper electric vehicles that can drive almost 24/7, and we can reduce the impact of charging on the grid.”

>> This article was originally published on our sister site, Power Electronics News.


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