This technology basically uses two electromagnetically linked coils that exchange power at high frequencies. The primary coil is placed in the garage, driveway, or road and connected to the grid, while the secondary coil is placed on the vehicle and charges the battery. Nowadays, wireless charging systems can be used in various electric vehicles.
A broader extension of wireless charging will be road charging, where inductive charging boards are placed along the road so that Tesla can wirelessly charge while driving. This technology can not only significantly reduce the cost of Cybertruck, but also significantly reduce the cost of all other Tesla models. By the way, for general electric vehicles, because they require smaller batteries and shift costs To the charging infrastructure.
The working principle of this technology is as follows: Placing an inductively coupled non-contact power transmission (IPT) system can effectively transfer power from a fixed primary power source to a movable or fixed secondary power source over a relatively large air gap. Although conductive chargers have many advantages such as simplicity and efficiency, inductive chargers are easy to use and are suitable for all-weather conditions. This is because there is no direct electrical contact between the vehicle and the charger, which can prevent the possibility of electric shock or arcing.
In the case of fixed/static charging, Tesla can upgrade the parking lot (or the existing charger-supercharger facility) to charge the electric car without plugging in any charging cables. Such a system can be buried or embedded installed, so that it will not affect the outer walls of the city, and will not be affected by vandalism and adverse weather conditions.
Compared with conduction charging, the main disadvantages of this charger are high investment costs and relatively high losses. My guess is that Tesla will eventually be able to solve this problem if they think it is a reasonable and cost-effective implementation; Cybertruck will be more cutting-edge and attractive in this way.
Another very important aspect of the inductive charging system that Tesla needs to consider is the health risks associated with personal exposure to radiation. The leakage field that penetrates into the space around the charging pad will affect the health of nearby organisms. It may also cause unnecessary heating of nearby foreign objects.
Different regulatory agencies have issued standards to limit exposure-ICNIRP (International Commission for Non-Ionizing Radiation Protection), IEEE, etc. There are different Z categories, where Z is the air gap (distance) between the primary coil and the secondary coil: Z1 (100-150 mm), Z2 (140-210 mm) and Z3 (170-250mm) and different powers Grade-3.7, 7.7, 11, 22 kW, in line with SAE J2954 standard.
Various systems have been developed in the past ten years aimed at charging individuals and public transportation. The power range of these prototypes is 2kW to 200 kW, the frequency is about 40-100 kHz, and the overall efficiency range from AC power to DC battery is 80% to 95%. The charging distance for mass-produced cars and public transportation vehicles is 50mm-400mm.
As for Cybertruck, Tesla needs to guide the magnetic field to reduce losses. This is a feasible requirement for these systems because they must be installed near the iron body. The third trend is to integrate different powertrain components and controllers into the vehicle.
There are many practical examples of stationary inductive charging, including a bus-based wireless electric vehicle charging system (WEVC). Such systems help reduce the weight of on-board batteries and improve efficiency. For example: Conductix-Wamplfler's WEVC is on buses in Turin, Geneo and s'Hertogenbosch in the Netherlands. According to reports, the efficiency of 60, 120 or 180 kW exceeds 90%.
WAVE IPT, a subsidiary of Utah State University, has been committed to developing a 50 kW IPT system with an efficiency of over 90%. They hope to install an IPT system with 250 kW charging power. In South Korea, OLEV, a spin-off company of the Korea Institute of Science and Technology (KAIST), has developed the third-generation wireless power transmission technology with a power transmission efficiency of 83% under an air gap of 20 cm.
As we have seen, this technology has many different methods and many different implementations. In my opinion, it will be included in the upcoming Tesla Cyber truck in 2023 (hopefully!) It is a very good feature. what do you think? Please share your comments below.
Nico Caballero is the Vice President of Finance at Cogency Power, specializing in solar energy. He also holds a diploma in electric vehicles from Delft University of Technology in the Netherlands, and enjoys researching Tesla and electric vehicle batteries. You can reach him via @NicoTorqueNews on Twitter. Nico reports on the latest developments in Tesla and electric vehicles in Torque News.
Post time: Feb-01-2020