As of my last knowledge update in September 2021, transformers are not directly used in electric vehicle (EV) wireless charging systems. Instead, wireless charging systems for electric vehicles often rely on a technology called inductive charging, which uses coils to transfer energy wirelessly.
Inductive charging works by creating a magnetic field between a transmitting coil (usually embedded in a charging pad on the ground) and a receiving coil (located in the EV). When the two coils come into close proximity, an alternating current (AC) is induced in the receiving coil, which is then converted back into direct current (DC) to charge the EV's battery.
Transformers, on the other hand, are devices that are used to step up or step down voltage levels in electrical systems. They work on the principle of electromagnetic induction but are typically used for changing the voltage levels in AC power distribution systems or isolating electrical circuits.
While transformers are not directly used in wireless charging systems for EVs, inductive charging can still be considered a form of electromagnetic induction, which is the underlying principle behind transformers. The main difference is that transformers are used to change voltage levels, while inductive charging is used to transfer power wirelessly.
It's worth noting that technology advancements and innovations are continuously occurring in the field of electric vehicles and wireless charging. Therefore, it is possible that new developments beyond my last update may have occurred, so I recommend checking more recent sources for the latest information on this topic.