Stability Investigation of Power Electronics Systems; A Microgrid Case

Abstract

This thesis is focused on the stability of systems containing high power electronic devices. The study mainly involves the exchanger device in a hybrid current microgrid. This microgrid has a topology with a DC bus and an AC bus. The stability analysis was performed for a small signal during short- and long-term perturbation. The short-term tests are presented in the frequency domain with the Nyquist stability criteria. This method has several practical advantages that facilitate its implementation. The long-term tests use eigenvalues and a semirecursive method to estimate the low frequency equivalent of the microgrid. A continuation method has been applied to analyze the stability of the system with the full information about the microgrid. The loadability and controllability of the system has been tested with this method.