Passivity-based control of synchronous motors in mine hoist systems

An adaptive PBC strategy for SM with a time-varying load torque to track flux and speed trajectories was proposed. The key point of this method was the identification of terms, known as workless forces, which appeared in the dynamic equations of SM but had no effect on the energy balance equation of the closed loop. PBC, combined with adaptive control schemes, not only preserved the advantages of PBC such as nonexistence of singularity, but also rejected the flux and speed tracking error caused by stator and rotor resistance variation. The rotor currents of SM were estimated via a state observer. This algorithm simplified the control structure and enhanced the robustness of the control system. The feasibility and effectiveness were confirmed by experimental results based on dSPACE. Supported by the National Basic Research Program of China(973 Program)(2005CB221505); the Special Scientific Research Foundation for Doctoral Subject of Colleges and Universities in China (20050248058)