Is wireless charging of electric vehicles the future of mobility? Judging by the turmoil in the industry, it would seem so: “Wireless charging of electric vehicles is emerging as an important market for the future. In addition to significantly simplifying the lives of drivers, who no longer have to fiddle with cables and connectors, it is a requirement. key to the autonomous mobility of tomorrow. The transmission efficiency of inductive wireless charging is comparable to that of plug-in systems, “explained Stefan Perras, Head of Pre-development and Innovation for Charging Infrastructure at Siemens.
Mobility
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It is no coincidence that the same giant Siemens has just signed an agreement with the German Mahle, one of the largest automotive suppliers in the world to achieve a standardization of systems and ensure full interoperability between vehicles and the charging infrastructure. And it is no coincidence that some of the tests will be carried out as part of publicly funded projects.
The case of Turin
The experimentation is at an advanced stage and a year has already passed since Stellantis inaugurated the ‘Future Arena’ for dynamic induction charging on the EV Day of 8 July 2021. The first vehicles (Nuova 500 and Bus Iveco E-Way) have been equipped to test the system and have already covered several kilometers with more than encouraging results. The goal is to demonstrate that the DWPT (Dynamic Wireless Power Transfer) system is one of the main candidate technologies to respond in an immediate and concrete way to the needs of decarbonisation and environmental sustainability in the mobility sector.
The main objective is to offer customers not only cutting-edge cars, capable of great autonomy and ultra-fast charging speeds, but also an ecosystem of services able to satisfy every need of an increasingly demanding clientele.
Hence the development of the dynamic Wireless power transfer (dwpt) technology which is able to recharge electric vehicles (ev) while they travel along appropriately equipped dedicated road lanes. The dwpt is an innovative system in the automotive sector consisting of coils placed under the asphalt that transfer energy directly to cars, trucks and buses without the need to stop at the appropriate stations to recharge the battery. The technology can be adapted to all vehicles equipped with a special ‘receiver’ capable of transferring energy from the road infrastructure directly to the electric motor, extending the range and safeguarding the vehicle’s battery charge. The pilot project of Stellantis and the partners involved is coordinated by A35 Brebemi, a company owned by Aleatica, a global operator in the transport infrastructure sector that deals with innovative and sustainable mobility solutions.
Mobility
Induction charging ready on the A35 Brebemi motorway
Costs? The ‘arena of the future’ project demonstrates that a bev vehicle, such as the new Fiat 500, equipped to test the system, can travel at high speeds without consuming the energy stored in the battery. Tests show that the efficiency of the energy flow from the asphalt to the car is comparable to the typical efficiency of fast charging stations. In this way it is not necessary to stop to recharge. Furthermore, the measurements relating to the intensity of the magnetic field demonstrate the absence of any effect on the driver, passengers and pedestrians.
The Chinese already produce series cars
But the primacy goes to the Chinese Zhiji Auto who first produced the 200 Zhiji L7 electric sedans, equipped with wireless charging and a range of over 100 kilometers. The company, a joint venture between the Chinese carmaker Saic Motor and the technology companies Zhangjiang Hi-Tech and Alibaba, started test drives starting last March 2022 and since April these cars are regularly on sale on the market. They can be recharged wirelessly in the experimental pilot points or – obviously – in the traditional way with the normal columns.
And Chinese-owned Volvo is also integrating and testing new wireless charging technology in an urban environment and considering its integration into future electric cars. For a three-year period, a fleet of electric XC40 Recharge models will be used as a taxi by Cabonline, a taxi operator in the Nordic region, and will be charged wirelessly at stations in Gothenburg, Sweden. The charging stations used in the test are provided by Momentum Dynamics, a supplier of wireless electric charging systems. Charging starts automatically when a compatible vehicle parks on a charging platform built into the street. The station sends energy through the charging pad, which is collected by a receiving unit in the car. To easily align the car with the charging pad, Volvo Cars will use its 360-degree camera system.
For XC40 Recharge electric cars, the wireless charging power will be more than 40 kilowatts (kW), making the charging speed about four times faster than an 11 kW AC wired charger and almost as fast as a 50 kW DC fast charger. kW wired. In total, the Volvo cars will be used for more than 12 hours per day and will drive 100,000 kilometers per year, which also makes this the first durability test of all-electric Volvo cars in a commercial use scenario.
The inductive charging giant is now thinking of cars
A response to the hyper-activity of the Chinese came from the US company Momentum Dynamics, a world leader in the sector and specialized in inductive charging systems, which is now expanding its attention to the car sector as well, as the collaboration with Volvo demonstrates. So far, the company has mainly focused on wireless charging for electric buses and trucks, but has now opened an entire division dedicated to cars with the stated goal of expanding the experimentation in Europe. The American company justifies the expansion of its activities in the passenger car sector “in response to the acceleration of global demand from customers for automatic wireless charging of private cars, particularly in the luxury segments and in the operations with taxis”.
Funding
The sector of wireless charging for electric cars is flying and there is no shortage of financing of all kinds. Easelink, Austrian developer of the Matrix Charging automated charging solution, has just raised 8.3 million euros in its latest funding round. The funds will be used to further expand Easelink’s product team, deepen cooperation with the automotive and infrastructure industry and continue the implementation of a global charging standard. Although the round was led by SET Ventures, the investments of the German energy giant EnBW and the Austrian energy supplier Wien Energie stand out from the point of view of electric mobility. The Easelink system consists of a ground-mounted charging pad. On the vehicle, a connector is mounted on the underbody that lowers onto the charging base, creating a conductive physical connection between the vehicle and the infrastructure. For the customer there is no need to handle the charging cable as he simply has to park the vehicle on the pad. Since there is a physical connection between the pad and the connector, it should be possible to achieve efficiencies similar to those of wired charging, unlike wireless charging. According to Easelink, the charging system is compatible “with most major electric car platforms”. It will be launched both as a retrofit version and as new vehicle equipment.
The future is in aftermarket devices
Being able to get owners of electric cars – even old ones – to wireless charging systems is of fundamental importance to spread these new infrastructures. For this WiTricity, a provider of wireless charging systems for electric vehicles, wants to offer owners of specific models of electric cars a retrofit package to use inductive charging. A beta version of the system is planned for the United States later this year. After testing, the system called WiTricity Halo Charging with 11 kilowatts of power will be more widely available in 2023, according to the company. However, WiTricity does not provide details on the beta test. The retrofit package includes three components: the energy receiver, which is installed on the vehicle; the wall box, which connects to the network; and the charging station, on which the car must position itself to start the wireless connection which can also be installed at a certain depth below the ground.
The search for the best universities in the world for optical wireless
A study by the Milan Polytechnic, conducted together with Stanford University, the Sant’Anna High School of Pisa and the University of Glasgow and published by the prestigious journal Light: science & Applications, has found a way to separate and distinguish optical beams even if they are superimposed and if the shape in which they arrive at their destination is drastically changed and unknown.
To make this possible is a programmable photonic processor built on a silicon chip of only 5 mm. The processor realized is able to receive all the optical beams through a multitude of microscopic optical antennas integrated on the chip itself, to manipulate them through a network of integrated interferometers and to separate them on distinct optical fibers, eliminating interference. This device allows to manage information quantities of over 5000 ghz, at least 100 times greater than current high-capacity wireless systems.
Similarly to what happens in optical fibers, also in free space light can travel in the form of beams having different shapes, called ‘modes’, and each of these modes can carry a flow of information. Generating, manipulating and receiving more ways therefore means transmitting more information. The problem is that free space is a much more hostile, variable and unpredictable environment for light than an optical fiber. Obstacles, atmospheric agents or more simply the wind encountered along the way, can change the shape of the light beams, mix them and make them at first sight unrecognizable and unusable.