Patent ID: 8987941
Filing Date: 2015-03-24
Classification: H02J

Abstract:
1. A power transmission system comprising: a power transmission apparatus including a primary-side coupling electrode configured to electrically couple to a secondary-side coupling electrode and connected to a load circuit of a power receiving apparatus, a high-frequency voltage generating circuit configured to generate and apply a high-frequency voltage to the primary-side coupling electrode, and a driving power circuit that supplies driving power to the high-frequency voltage generating circuit; a center frequency acquiring unit configured to sweep a frequency range to acquire a center frequency in a state in which electrical coupling between the secondary-side coupling electrode and the load circuit is weakened, the center frequency being a frequency at which the generated high-frequency voltage is minimized or substantially minimized with respect to variation in frequency of the high-frequency voltage generated by the high-frequency voltage generating circuit; and a control unit configured to set a driving frequency, which is the frequency of the high-frequency voltage generated by the high-frequency high voltage generating circuit, to the center frequency or a frequency near the center frequency and supply power to the power receiving apparatus; wherein a resonant frequency of a first resonant circuit composed of the primary-side coupling electrode and the high-frequency voltage generating circuit substantially coincides with a resonant frequency of a second resonant circuit composed of the secondary-side coupling electrode and the load circuit, and wherein the center frequency acquiring unit is further configured to acquire the high-frequency voltage within a frequency range including the frequencies of two coupling modes occurring in a state in which the first resonant circuit is coupled to the second resonant circuit.