: This paper proposes a hybrid flux-weakening control method for achieving maximum-speed operation of a wound field synchronous motor (WFSM). During high-speed operation, the stator inductance varies nonlinearly with the stator and field currents, and reflecting this variation is essential for reaching the maximum speed. However, constructing a high-resolution lookup table (LUT) requires extensive measurements, and using a full stator inductance LUT demands considerable memory and computation. Therefore, the proposed method transitions between two flux-weakening methods so that the operating point can reach the maximum-speed region. The switching point between the two methods is accurately determined by incorporating nonlinear variations in the d-axis inductance obtained from finite element analysis. As a result, the proposed method achieves maximum-speed operation using only a single-variable LUT defined within a limited field-current range, which greatly reduces memory requirements. The effectiveness of the method is validated through simulation results on a 5-kW WFSM.