Electrically Excited Synchronous Motors (EESMs), which generate magnetic fields by externally supplied DC excitation currents, have gained attention in electric vehicle applications due to their wide speed range, adjustable power factor, and cost-effectiveness. However, conventional Permanent Magnet Synchronous Motors (PMSMs) control strategies are not applicable to EESMs because the latter feature controllable excitation currents. This study proposes a full-speed-range control algorithm for EESMs. A three-dimensional lookup table is constructed using excitation current, flux linkage, and torque as inputs to determine optimal stator currents. Then, an iterative search method adjusts the excitation current to minimize copper losses. The final reference current set for stator and rotor is derived through this process. When the range of excitation current remains fixed, three 3D lookup tables can be precomputed offline, with flux linkage and torque as inputs and stator and rotor currents as outputs. Simulink simulations confirm the effectiveness of the proposed algorithm.

Direct Flux Control,Efficient control algorithm,Electrically excited synchronous motor,Field Weakening Control,Maximum Torque per Ampere