Optimal control of the hybrid excitation synchronous machine for electric propulsion in electric vehicle

This paper presents an optimal current control for the hybrid excitation synchronous motor in electric vehicle application. The whole electric propulsion system is modeled including the battery and converters. The control aims to meet the torque and speed requirements while insuring minimal copper and iron losses as well as inverter and chopper losses. Extended Lagrange multipliers optimization method (Kuhn-Tucker conditions) is used to elaborate analytical expressions for the optimal reference armature and field currents with respect to armature current and voltage constraints. Simulation over the New European Driving Cycle proves that the proposed optimal control leads indeed to the lowest losses.