RESONANCE FREQUENCY CONTROL METHOD, POWER TRANSMISSION DEVICE, AND POWER RECEPTION DEVICE FOR MAGNETIC-RESONANT-COUPLING TYPE POWER TRANSMISSION SYSTEM

摘要

Provided is a magnetic-resonant-coupling type power transmission system, wherein power is transmitted from a power-transmission side coil to a power-reception side coil utilizing magnetic resonant coupling, and wherein the resonance frequencies of the coils can be adjusted at high speed, with accuracy, and in real time. In this magnetic-resonant-coupling type power transmission system, the phase of the voltage supplied to the power-transmission side coil, and the phase of the current flowing through the power-transmission side coil or the power-reception side coil are detected, and the resonance frequencies of the power-transmission side coil or the power-reception side coil are varied so that the difference between the phases will become a target value. The power-transmission side coil comprises a power supplying coil to which an AC power supply is to be connected, and a power-transmission resonance coil electromagnetically coupled closely with the power supplying coil. The power-reception side coil comprises a power-reception resonance coil, and a power extraction coil electromagnetically coupled closely with the power-reception resonance coil. The phase difference between the phase of the voltage of the AC power supply and the phase of the current flowing through the power-transmission resonance coil is controlled to become a target value (ß), and the phase difference between the phase of the voltage of the AC power supply and the phase of the current flowing through the power-reception resonance coil is controlled to become a target value (ß - p/2).