Vietnamese associate professor makes a wireless charging system for electric cars

Assoc. Prof. Dr. Ngo Dang Luu researched a wireless charging station model that helps cars automatically charge when entering an area with a charging dock without stopping the vehicle, with a transmission capacity of 80 kW in 5-10 minutes.

Dynamic charging technology was researched by Associate Professor Luu while studying for a doctorate in electrical, electronic and computer science at the University of Munich (Germany) in the period 2010-2015. The idea came when he saw the solution for electric cars with batteries. Solar energy on the roof of the car with a mechanism to run and charge the battery. From there, he learned about dynamic wireless charging technology, a form of electrical energy transmission while the vehicle is running.

Associate Professor Luu said that the current technology is wireless charging, but it is static charging, which means the car has to stop charging until the battery is full. This technology needs a long charging time, the car has to stop at the station, so it is quite inconvenient. In addition, when static charging makes the distance traveled after each charge is short, the capacity and weight of the battery is large. Dynamic charging technology can create a charging lane for multiple vehicles at the same time.

Associate Professor Ngo Dang Luu introduces the design model of a dynamic wireless charging system. Photo:  Ha An

Returning to Vietnam in 2015, Associate Professor Luu began developing models to test the effectiveness of the dynamic charging technology he studied. The charging line is designed by him with charging bases, each containing a primary coil with a special structure that works on the principle of a loop using a magnetic field connected to a secondary coil mounted on the vehicle. Based on this looping principle, when the car runs through the charging line, it will create a charge current into the charger on the car. “This technology is similar to wireless phone charging but is static charging, and the solution I have for cars is dynamic charging technology,” said Associate Professor Luu.

To increase efficiency, he said, it is possible to increase or decrease the loop distance (primary and secondary winding distance) by an optimal level. According to calculations and simulations in the laboratory, this technology can give a maximum charging capacity of 80 kW in 5-10 minutes, with a transmission distance of 0.5 m. This time can help the car charge quickly without stopping.

In addition to the hardware system, he also developed an artificial intelligence model based on data collected from the charging and driving process to develop software to monitor, adjust the electrical system, and charge the vehicle to help. Optimize battery performance. Through the software, users know the battery status, the time the battery runs out to help the battery last longer. His software for predicting the full and empty batteries in his battery was licensed in October 2022. The dynamic charging system is in the process of applying for a patent.

According to Mr. Le Trung Hieu, electrical – electronic engineer, director of Ewater technology company, the application of charging technology for vehicles while running in a number of countries such as the UK, Malaysia … has studied in the past few years and has a high practical application base. Regarding the mechanism of operation, he said that the simplest understanding of this is the technology of using 2 coils with the function of receiving and transmitting electromagnetic waves, one placed under the road surface (with transmitter function), one placed on the vehicle (with transmission function). has a receiver function) and then charges the battery. The longer the distance, the more electricity the car charges during the ride.

However, according to Mr. Hieu, despite the potential, the author just did the laboratory scale, it is necessary to do practical work to have a closer assessment. He noted that currently, battery systems on electric vehicles for charging last a few tens of minutes, and for fast charging are not currently available on vehicles and need further research. In addition, the integration of a dynamic wireless charging system on vehicles will incur higher investment costs because the vehicles already have charging technology in use. The current standardized charging station infrastructure also needs to change if this charging technology is applied. “The author needs to have investment participation with a car company oriented to this technology to integrate the technology into the vehicle and charging station infrastructure from the very beginning to reduce costs, more realistic application goals.” Mr. Hieu said.

Wireless power transmission is a widely used technology, and wireless charging is one of its typical applications. The wireless power transmission system enables the transmission of energy through the air with high efficiency and distances from a few millimeters to several hundred millimeters. One of the biggest risks when implementing wireless charging technology for electric vehicles is that it must be designed and implemented correctly, wireless charging technology can cause accidents and endanger users.