Stator side voltage regulation of permanent magnet AC generators

Constant voltage, variable frequency AC power systems are emerging as a preferred system in future vehicular and aircraft electrical systems. The goal of the research presented in this dissertation is to develop the application of permanent magnet generators in such systems. The load power, load power factor, and the shaft speed of the generator are variable quantities. The small power system may be viewed as a constant voltage, variable frequency AC power system.;This research presents the approach for voltage regulation of the permanent magnet generator from the stator terminals. It is well known that injection of reactive power into the stator may affect the stator voltage and may therefore be used as a means of controlling the stator voltage. A system level design oriented analysis leads to the identification and optimization of machine designs with saliency to minimize additional current loading in the stator and the reactive power source. The mitigation of controller shut-down and generator short circuit failures is integrated into the design oriented analysis. Various methods of generating the reactive power necessary to accomplish stator side voltage regulation are examined and the STATCOM is identified to be the preferred approach.;While a highly accurate, full order simulation model is used to verify performance, a reduced order model is used to develop the controller approach. Control of the magnitude and angle of the STATCOM output voltage is identified as an elegant control method that yields high performance AC voltage regulation using an inner DC voltage regulator loop. The use of power derivative feedback is presented and applied to the control design to improve the damping of the generator response for cases where inherent system damping may be poor. The operation of the overall system has been verified using simulations and laboratory scale prototype demonstrations.;The proposed system configuration, particularly with variable frequency operation of the power system, leads to the realization of attractive properties such as excellent voltage regulation, rejection of phase unbalance and harmonics, and relatively benign failure modes.;This work firmly establishes the basis of advancing the adoption of permanent magnet generators in vehicular power systems.