Technology Overview

Wireless EV charging is a rapidly growing technology area driven by cordless EV charging application. It is the enabler for dynamic charging while the vehicle is being driven.

The key components of a conventional EV wireless charging system include a high frequency transformer with transmitter pads installed on the road and a receiver pad installed on the EV body. There are resonant compensation circuits, a high frequency inverter, a high frequency rectifier, etc. The airgap distance between transmitter and receiver for EV charging application is around 15 cm to 25 cm. The weak magnetic coupling between transmitter pad and receiver pad creates many engineering challenges to simultaneously meet the high power and high efficiency requirements for wireless EV charging. The operation frequency of the transformer ranges from 30 kHz to 90 kHz. The power transfer efficiency of a conventional wireless charging system depends on the transmitter and receiver design, compensation network design, switching loss of the inverter and rectifier, and the converter control solution. A design tradeoff is made on transmitter and receiver pad size, output power, switching frequency, efficiency, and electromagnetic interference (EMI) compliance requirement. The achievable efficiency of wireless charging system varies in the range from 75% ~ 95%.

This technology offer is a new wireless charging converter circuit and control solution for high efficiency, high frequency operations for higher power wireless charging systems. The technology provider is looking for industry collaborators to work together to transfer this technology into a cost-effective and reliable EV wireless charging product.

Technology Features, Specifications and Advantages

This new circuit design and new control solution improves the wireless charging system control stability. It can achieve consistent high efficiency operation of wireless charging system with around 10% to 15% efficiency improvement in worst case battery charging operation condition, as compared to a conventional wireless charging control system solution.

Potential Applications

This new circuit design and new control solution is applicable for high efficiency, higher frequency, and high-power EV wireless charging product development and implementation. The tools have been developed for the wireless charging transformer pads design, the resonant compensation network circuit parameter calculations, the wireless charging system circuit simulation, and the wireless charging control system hardware performance validation.

Customer Benefit

This technology offer allows better efficiency in wireless charging implementation for electric vehicles. The electrical energy savings can be achieved from around 10% ~ 15% power efficiency improvement in wireless EV charging operation. The various tools that have been developed for this technology allow ease of implementation and performance validation of this technology.