Method for controlling power in wireless power transmission assembly and wireless power assembly thereof

Provided are a power control method in a wireless power transmission assembly and the wireless power transmission assembly. The method includes: outputting (S7) a direct current voltage to wireless power transmission apparatus, the direct current voltage generated from an alternative power source in an adaptor; and changing the size of the direct current voltage in the adaptor based on a voltage changed communication signal if the wireless power transmission apparatus transmits the voltage change communication signal to the adaptor.