Evaluation of primary-side power supply coil shape to expand the charging area in a contactless power transmission system

This paper deals with the magnetic flux distributions when the shape of the primary-side power supply coil is changed to expand the charging area in a magnetic resonance power transmission system. In the conventional system, one primary-side power supply coil generally supplied to one secondary-side power reception coil. However, if the one primary-side power supply coil can supply to several secondary-side coils, the problem of many power cables is solvable. In this case, it is required that the primary-side coil enlarges the power supply distance and power supply range. This paper addresses the characteristics of the power supply ranges when the solenoid coils are used as the primary-side coil. The coil lengths of the solenoid coils are changed to 20 mm, 100 mm and 200 mm, and the diameter of each coil is 61 mm. The power supply ranges are measured with the receiving antenna of 25 mm diameter. Though the coil length of the solenoid coil hardly influences the power supply range in the axial direction, the power supply range in the radial direction is extended.