| 摘要 |
PROBLEM TO BE SOLVED: To provide a wireless power transmission system capable of detecting a foreign object even when a distance between a power transmission coil and a power reception coil has varied.SOLUTION: A wireless power transmission system 1 comprising a power transmitter 10, power receiver 20, power transmission coil 30, and power reception coil 40 transmits, with no contact, power by using magnetic field coupling between the power transmission coil 30 and power reception coil 40. At least one of the power transmission coil 30 and power reception coil 40 is a coil having a symmetric shape. The wireless power transmission system 1 includes: magnetic field strength detection means 60 for detecting strength of a magnetic field around the coil having the symmetric shape; and foreign object detection means 70 for performing foreign object detection by using the magnetic field strength detected by the magnetic field strength detection means 60. The foreign object detection means 70 detects a symmetric property of magnetic field strength from the magnetic field strength detected by the magnetic field strength detection means 60 to perform the foreign object detection on the basis of a variation in the symmetric property of magnetic field strength.SELECTED DRAWING: Figure 1 |
