Beschreibung
In this work, a PMLSM is investigated with the aim to improve the quality of a transportation task in an industrial manufacturing environment. A major goal of this thesis is to arrive at a detailed understanding of the electric machine. This is achieved by deriving a thorough mathematical model, which is capable of reproducing the magnetic and electric behavior for various operation scenarios. On the basis of the calibrated model, an indirect force control strategy is developed, where a current controller tracks current references, which are calculated according to desired forces. A systematic approach for the calculation of the current references is proposed as an optimization problem, where the ohmic losses in the stator coils should be minimized while the deviation between the modeled force and the desired force becomes small. The current controller is implemented as a flatness-based feedforward controller and a PI-like current error feedback controller. Since the central purpose of the motor is to move the shuttle along predefined trajectories, the indirect force controller is extended by a flatness-based position controller to form a cascaded motion control structure. The controller is compared with the industrial standard in the form of a field-oriented control strategy. Both concepts are evaluated on a test bench for a variety of scenarios and motor configurations. While the tracking accuracy of the position and forces serves as the main attribute to evaluate the proposed concepts, a special attention is paid to the efficiency of the optimal control strategy. A substantial reduction of the ohmic losses was achieved in comparison to the industrial standard control concept while the tracking performance showed an improvement for various operation scenarios.
