Study on the characteristics of power transmission side of leaky magnetic field canceling coil for non-contact power transfer while in operation

Recently, automated guided vehicles (AGVs) have been deployed in factories to improve work efficiency and reduce labor shortages. However, current power supply systems, such as AGV shift systems and battery replacement systems, cannot fully utilize the advantages of these systems because of the time they are inactive. Therefore, to improve work efficiency, we have adopted an in-transit non-contact power supply system that can supply power while the work is in progress and while the machine is moving. There are several non-contact power supply methods; however, the most widely used electromagnetic induction method was used in this study. Compared to conventional non-contact power transfer, a stable power supply and reduction of magnetic leakage field are more important for non-contact power transfer while traveling because of its characteristic of transferring power over a long section of the track. Therefore, we investigated the characteristics of a cancellation coil with enhanced effectiveness based on an 8-shaped coil that reduces the leakage of magnetic fields using electromagnetic field analysis simulations. We then fabricated a feeding coil and verified its effectiveness using actual measurements. As a result, it was confirmed that the cancellation coil has superior magnetic field leakage reduction performance compared to the ordinary 8-shaped coil.