| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that there are safety and transmission performance limitations with the background technology since adjusting an operational frequency so as to maintain series resonance causes increase of a voltage applied to transmission electrodes, and to provide power transmission system and a transmission device which can improve transmission performance.SOLUTION: A power transmission device 10 comprises power transmission electrodes E1 to E2 for exciting electric fields on the basis of AC voltage applied through a transformer 20, where the transformer 20 and the power transmission electrodes E1 to E2 forms a resonance circuit. A power reception device 30, on the other hand, comprises power reception electrodes E3 to E4 performing electric field coupling to the power transmission electrodes E1 to E2, a transformer 32 and rectifier circuit 34 which supply AC voltage excited at the power reception electrodes E3 to E4 to a battery 36. A CPU 16 repeatedly changes a frequency of the AC voltage applied to the power transmission electrodes E1 to E2, and measures impedance in parallel with the change. The CPU 16 also retrieves a frequency at a time point when the measured impedance shows a decrease tendency satisfying a predetermined condition toward a resonance frequency of the resonance circuit, and sets the retrieved frequency as a frequency of AC voltage at power supply time. |
