Stability-assured design of a full state feedback controller for a three-phase grid-connected converter using disk margin analysis
Marek Michalczuk, Andrzej Gałecki, Bartłomiej Ufnalski, Krzysztof Jackiewicz, Arkadiusz Kaszewski
Abstract
The paper proposes a tuning procedure for a multioscillatory current controller in a three-phase three-wire grid connected converter operating under distorted voltage conditions. The control system should provide high quality sinusoidal currents. This is achieved by implementing internal models of expected disturbances - multioscillatory terms. Tuning of such systems is challenging if the objective is to guarantee a certain level of stability margins. The multiloop disk margin analysis may be a perfect candidate solution. This analysis combined with a global optimization produces controller gains that can be transferred to the physical system. The paper provides the first complete experimental verification of the multioscillatory full state feedback grid current control system with a designer specified stability margin in the form of disk radius.