This paper proposes a position-insensitive wireless power transfer (WPT) system which can realize zero phase angle (ZPA) and constant voltage (CV) output only by primary variable frequency control. An integrated electromagnetic coupler is introduced, as well as its 3D simulation model and equivalent circuit model. The self-compensating principle of the WPT system is presented, and the condition for achieving ZPA and CV output is given. Through Maxwell simulation, vast amounts of data about capacitances and inductances of the coupler varying with the transfer distance and misalignment distance is obtained. With the obtained data, the artificial neural network (ANN) model based on back propagation algorithm is established for parameter prediction, so as to solve the resonant frequency. Therefore, the switching frequency can automatically follow the change of the transfer distance and misalignment distance of the coupler. When the transfer distance, misalignment distance and load resistance change, the output voltage of the system can keep constant without any DC/DC control circuit or voltage regulation control. Finally, a simulation model is built, which verifies the feasibility and effectiveness of the proposed WPT system.