Case study of energy near-optimal control strategies for traction drives with AC motors

摘要

The main contribution of this paper is design, description and verification of a new rest-to-rest position control systems applied to the train with AC traction motors that is energy near-optimal with respect to combined electrical and mechanical consumed energy minimization. All calculations are related to the one traction motor yielding its best exploitation. The load torque consists of constant, linear and quadratic components with respect to the rotor speed. The closeness to optimality is assessed by simulation, comparing the energy expenditures of the new energy saving control system with that predicted by computed optimal control. The application of the energy saving control system is rendered straightforward by using a symmetrical trapezoidal speed-time profile. This is provided by an energy saving reference position generator whose output is faithfully followed by means of a feedback control law based on forced dynamics control yielding a prescribed closed loop dynamics together with a matched zero dynamic lag pre-compensator. Presented simulation results confirm the possibility of achieving energy savings.