1：What is it used for?
Wireless charging technology allows electric vehicles to be charged without relying on charging cables. It achieves contactless power transmission through methods such as electromagnetic induction, electromagnetic resonance, and radio frequency.
2：Advantages
Electric vehicles with wireless charging eliminate exposed connectors, making them adaptable to various harsh environments and weather conditions, while avoiding safety hazards like electric leakage or short circuits.
It offers convenience as vehicles only need to be parked in a designated location for charging, without the need for supervision.
The power source and transformers are concealed underground, saving space.
3：Disadvantages
Wireless charging has lower power capacity and can only provide slow charging, resulting in lower efficiency compared to wired charging.
Inductive charging requires strict positioning of the vehicle.
Wireless charging systems tend to be more expensive than charging stations, and different brands have varying charging standards.
4：Classification
The main types of wireless charging for electric vehicles are electromagnetic induction and magnetic resonance.
Electromagnetic Induction:
This is the most commonly used wireless charging method. It operates on the principle of electromagnetic induction, where a primary coil on the transmitting side and a secondary coil on the receiving side enable the transfer of energy by generating current in the secondary coil through electromagnetic induction. It has the advantage of higher conversion efficiency but limited charging distance, allowing only one-to-one charging.
Magnetic Resonance:
Magnetic resonance wireless charging consists of a power transmitting device and a power receiving device. When both devices are adjusted to the same frequency or resonance frequency, they can exchange energy with each other. This principle is similar to the resonance of sound. Coils with the same vibration frequency arranged in the magnetic field can transfer power from one coil to another. Resonant charging offers a longer transmission distance compared to conventional inductive charging. It can simultaneously charge multiple vehicles without requiring precise alignment. However, it incurs higher energy loss during transmission.
5：Further Reading
In 2013, South Korea completed the construction of a 12-kilometer wireless charging bus lane. The underground infrastructure of the lane utilized resonance wireless charging technology. By forming a 20kHz frequency electromagnetic field on the road surface, buses equipped with compatible stabilizers and inverters were able to generate electric power.
