Energy Optimal Control of Electromechanical Systems: Trade-off Demands

This study presents research on the impact of the selection of the required manoeuvre time on the energy consumption of an electromechanical system, using the example of a train. Two different energy conservation control strategies [energy optimal control (EOC) and energy near-optimal control (ENOC)] were applied to assess their consumption as a function of recommended travel time. The optimal control variables are provided by an energy-saving reference position generator, whose outputs are then faithfully followed using a feedback control based on field orientation, and this is accomplished with a matched zero dynamic lag pre-compensator, yielding the required closed-loop dynamics. The load torque, consisting of constant, linear and quadratic components as a function of speed, is treated as a state variable. The potential for energy savings by reducing the speed of such systems was verified through MATLAB simulations. As a representative controlled electromechanical system, a suburban train unit was chosen for simulations to evaluate the energy consumption of both control approaches.