The Design of the Wireless Pick-up Module of On-line Electric Vehicles to Increase Amount of the Magnetic Flux Density

Abstract

The application of online electric vehicles (OLEVs) in mass transportation and smart factories is gaining much attention. It considerably helps electric vehicles and automatic guided vehicles (AGVs). It will no longer need large capacity batteries for the power supply and avoid a long charging process. Therefore, we do not have to worry about charging demand caused by power shortages. The activation of AGVs in smart factories will be improved and no longer be limited to charging stations. At present, the main problems encountered by OLEVs are the efficiency of reception and the cost of construction. In this paper, an oval pick-up module with a compensation structure is proposed for OLEVs. It is compared with the uncompensated structure to show the difference in the 2D magnetic field by using the Finite Element Analysis (FEA) in the air gap from 0 to 7 cm. In addition, the oval pick-up coil is more conform to the power transmission of OLEVs. Its winding method enables the compensation coil to reduce magnetic leakage. The simulation results show that adding a compensation coil enhances the magnetic field receiving efficiency. The pick-up amount of magnetic flux density increases by 42% when the air gap between AGVs and the ground is 5 cm. Therefore, the wireless charging efficiency and the charging time improve.