Control of electrically excited synchronous motor in the field weakening range

Abstract

In the current thesis, the control system for the electrically excited synchronous motor is investigated. The main topics within the work are field oriented control, field weakening, reaction control, robustness. The field weakening technique is used to increase the motor operational speed range to the limit of double nominal speed; in the control system field weakening is implemented as a flux limiter. Two different excitation control principles are studied: unity power factor control and reaction control; their impact on the drive performance is investigated, and the results are compared. The stator flux linkage reference vector, the stator current controllers tuning, and the torque load rise time are the drive tuning parameters researched. To enhance the drive robustness, the voltage model based estimator with the current model based correction term is implemented. During the simulations in MATLAB Simulink, the drive dynamic performance, as well as the robustness to the internal disturbances was tested. The results obtained justified the control system efficiency in dynamic performance.