In this study, we propose a three-phase wireless power transfer system implementing unbalanced-current control with zero-phase current. The control allows uniform power transfer with maximum transfer efficiency regardless of the receiver coil position. The control is applied to the circuit configuration with an inductor in zero-phase, which can cancel the mutual inductances between the phase-coils in the transmitter. The experiments with a prototype of the three-phase wireless power transfer coil for automatic guided vehicle (AGV) confirm that the system implementing the control can perform uniform and efficient power transfer to an AGV irrespective of whether it is moving or at standstill.