Coil alignment method in wireless power transfer system and apparatus using the same

A coil alignment method performed in a ground-side coil alignment apparatus coupled to a ground assembly (GA) controller, the coil alignment method comprising:

• generating a first beam bar extending in a first direction and a second beam bar extending in a second direction perpendicular to the first direction on a GA coil positioned in a wireless charging area using a first light-emitting element, a first light-receiving element, a second light-emitting element, and a second light-receiving element which are each spaced apart from the GA coil by a predetermined distance;
• moving a ground-side wireless power transfer pad having the GA coil, the first light-receiving element, the second light-emitting element, and the second light-receiving element in the first direction;
• detecting whether the second beam bar is blocked by a light-blocking unit protruding from a lower part of a vehicle;
• stopping movement of the ground-side wireless power transfer pad when the second beam bar is blocked;
• moving the ground-side wireless power transfer pad in the second direction;
• detecting whether the first beam bar is blocked by the light-blocking unit;
• and
• stopping movement of the ground-side wireless power transfer pad when the first beam bar is blocked.

A coil alignment method performed in a ground-side coil alignment apparatus coupled to a ground assembly (GA) controller, the coil alignment method comprising:

• emitting a first beam in a first direction by controlling a first light-emitting element spaced apart from a GA coil positioned in a wireless charging area by a predetermined distance;
• emitting a second beam in a second direction perpendicular to the first direction by controlling a second light-emitting element spaced apart from the GA coil by a predetermined distance;
• transmitting a first stop signal to a vehicle assembly (VA) controller of a vehicle parked in the wireless charging area when the first beam is not detected in a first light-receiving element installed to sense the first beam;
• and
• transmitting a second stop signal to the VA controller when the second beam is not detected in a second light-receiving element installed to sense the second beam.