Standardization of wireless charging is progressing with 3.7 and 7.7 kW power levels currently being testing on the front line, and the 11 kW power level is soon to enter its own stage of final testing.
Now, according to the latest reports, the power level of J2954 is to reach 250 kW, with applications in both the light duty and heavy duty vehicle fields in mind (50-250 kW).
The bus can be wirelessly charged at one of its stops via a charging station located under the road surface (1). A receiver, mounted in the bus floor, absorbs electric energy (2) and charges the battery
A new and interesting feature also now mentioned in the wireless charging segment is vehicle alignment over the station through magnetic field generation (which would be especially useful for autonomous charging). The question is (as always) what method to use for standard recommended practice?
"The Recommended Practice SAE J2954 will also contain guidance for vehicle alignment methods and determine a common location for the wireless charging ground assembly. Currently, magnetic field alignment through triangulation using the existing coils and alignment using an auxiliary antenna are being evaluated for this decision.
The goal is to provide one methodology to align in order to be able to charge with high efficiency all SAE J2954 stations. This is for both manual (self-parking) and autonomous (automated) alignment possibilities. It is important to know that the only way to charge an autonomous vehicle automatically is to use wireless charging and SAE J2954 Recommended Practice will standardize this.
The final news is SAE International's proposal to start pilot infrastructure projects with wireless charing from 2019 (California and ZEV states).
"The first stage, for light duty vehicles, creates an infrastructure based on J2954 (for example in malls, large workplaces, condominium complexes, etc). SAE also proposes 100 Heavy Duty Chargers in 2020 based on SAE J2954/2 (for example public transit agency, truck stops for anti-idling, etc.) in 2021 to create a wireless charging infrastructure with alignment communications for autonomous vehicles (for example, taxi fleets)."
source: Green Car Congress