In 2017, the global sales of new energy vehicles exceeded the 1 million mark for the first time. The booming new energy vehicles have driven the development of related technologies, and wireless charging technology is one of them. The concept of wireless charging technology has been proposed since the 19th century, and research institutions have successively carried out technology research and development; after 2007, wireless charging technology has entered a stage of rapid development; around 2010, the automotive industry began to apply related technologies one after another. In recent years, wireless charging has become a hot spot, and many parts suppliers, car companies and technology companies have launched tests of wireless charging for new energy vehicles.
Kia successfully tests wireless charging technology
Only have expensive luxury cars to enjoy. Recently, Kia Motors announced that after 3 years of research and development of fast charging wireless technology, they have cooperated with the US wireless charging technology company Mojo Mobile and the Energy Office of the Ministry of Energy Efficiency and Renewable Energy to conduct wireless charging on a fleet of Soul electric vehicles. The Soul electric car is also the only electric model currently on sale by Korean automakers. It is reported that Kia’s wireless charging technology can provide more than 10 kilowatts of electricity for the car, and the charging efficiency can reach 85%. It is worth noting that even if there is a deviation from the charging device when parking, it will not affect the normal charging, which is definitely good news for drivers with poor parking skills.
The wireless charging of electric vehicles is similar to the wireless charging of mobile phones. Car companies will install a transmitter coil (transmitter coil) on the ground, and a corresponding receiver coil (receiver coil) will be installed in the car. When the two coils are connected in a straight line, the An electromagnetic field is formed between the transmitting and receiving coils, and the transmission of electrical energy is realized. But like the wireless charging of mobile phones, electric vehicles also have the problem of energy loss in the process of wireless charging, so car manufacturers and research institutions are currently trying to improve the charging efficiency as much as possible.
Kia also admitted that the current wireless charging system has not been able to achieve mass production, but there has been a significant improvement in energy output and efficiency.
Static wireless charging: Parking and charging
At the end of 2017, Continental announced that it would launch a wireless inductive charging pad equipped with sensors. It is understood that this wireless charging network system mainly relies on the charging board placed in the ground to emit electromagnetic, and the induction coil on the car receives the electromagnetic and uses the electromagnetic conversion principle to charge the vehicle battery. Combined with a micro-navigation unit, the system allows the vehicle to be accurately parked over the charging pad, which is 10 times more accurate than conventional parking assist systems.
Continental says the wireless charging system can power up to 11 kilowatts and be as efficient as 90 percent, with a 90-second charge for 1 mile and a 20-minute charge for 20 kilometers. It is reported that the technology has been installed on the BMW 530e model, and will be applied to some Mercedes-Benz models in the future. In addition, Continental is currently working on fully deploying wireless charging transmitters in car parks, so that electric vehicles can also be recharged in small amounts at any time while driving.
PluglessPower System by Evatran
Back in 2016, Evatran developed the PluglessPower system to provide wireless charging for the Tesla Model S. The system consists of two parts, a charging pad and an adapter. The charging board is placed on the ground or in a parking space, and is connected to the power supply through a cable; the adapter needs to be installed on the bottom of the electric vehicle by a professional. Simply put, it accepts the power of the charging board through the adapter to realize wireless charging. Once installed, the user simply parks the car on the charging pad to charge it up to 20 miles per hour on a charge, taking about 10 to 12 hours to fully charge the Model S, depending on battery capacity.
According to reports, the wireless charging system provided by Evatran has a wireless induction of 7.2 kilowatts per hour, which is enough to ensure the daily charging of MODELS.
Dynamic wireless charging: charging while open
In May 2017, Qualcomm announced that it had completed a trial of wireless charging in electric vehicles, that is, adding inductive charging devices on the road, so that the car can be charged while driving. It is reported that at a speed of 100Km per hour, the wireless charging power of 20 kilowatts can be achieved, and the wireless charging of two moving vehicles has been tested at the same time. Unlike most inductive charging, Qualcomm Halo technology provides high energy transfer across the air and is suitable for a variety of vehicle types. Its multi-coil design allows efficient energy transfer even when the charging pad is misaligned with the vehicle.
WiTricity is a start-up company born out of an MIT lab that has focused on wireless charging technology for over 10 years. Mainly doing wireless charging technology based on magnetic resonance, that is, using the near-field spatial magnetic field for energy transfer, through the selective energy exchange between the highly efficient coupled resonators, the precise adjustment and matching between the power supply and the receiving device can be achieved. 245 patents. WiTricity’s wireless charging is similar to Qualcomm’s Halo technology, making it a competitor. But WiTricity doesn’t plan to manufacture the hardware used in the car’s wireless charging system itself, but will license its intellectual property to others and provide partners with reference designs to build the hardware on. At present, WiTricity has cooperated with Toyota, GM, Nissan and other car companies.
Wireless charging for cars has a bright future
It is understood that the advantages of wireless charging are mainly reflected in three aspects:
- The first is high safety, because wireless charging does not require a plugging process, and it is not affected by weather and extreme environments such as rain and snow, and can be used normally in the face of complex working conditions.
- The second is high reliability. Compared with wired charging, wireless charging has no mechanical wear.
- The third is good convenience, which can realize automatic charging and solve the problem of convenience in the last mile of unmanned driving.
However, in the process of gradually accelerating the industrialization of wireless charging, it has encountered the constraints of ununified standards, few engineering practices, and high application costs.
Although faced with many problems, with the rapid development of new energy vehicles, the application and popularization of wireless charging technology may only be a matter of time.