Position estimators of surface permanent‐magnet synchronous motors are often designed with local stability and thus may be unstable under a large estimation error. To overcome the risk of instability, a globally stable position estimator is proposed in this paper. The proposed estimator is derived from an alternative expression of the stator model, which has the rotor position as the only parameter inside. Stability analysis of the estimator and conditions for global stability are obtained without any approximation. Design rules for global stability, dynamic, and tracking performances are clearly given. All theoretical results are finally verified by experiment. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.