Wireless Power Transfer System and Control Method Thereof

A wireless power transfer system and a control method thereof. The wireless power transfer system includes: a transmitter coil configured to be magnetically coupled to a receiver coil; a power conversion device coupled to the transmitter coil; and a controller including a one-half cycle detection block, wherein the one-half cycle detection block is configured to establish a current sensing time instant, and wherein at the current sensing time instant, a current flowing through the transmitter coil is detected and compared to a predetermined threshold to perform foreign object detection to determine whether a foreign object is coupled to the wireless power transfer system.