Eigenvalue analysis of microgrids using linearization and system identification techniques

In this paper the dynamic behavior of a microgrid is investigated using eigenanalysis and system identification techniques. A detailed nonlinear model of the microgrid is developed in Matlab/Simulink and is used to obtain a linearized approximation to perform eigenanalysis. Moreover, the system eigenvalues are also analyzed by applying a system identification technique on the dynamic responses. The results from both methods are compared and evaluated. A microgrid with rotating and inverter-interfaced units is studied and results for various operating scenarios, such as changes in the synchronous generators torque, load changes and changes in the inverters setpoints, are presented. The influence of each parameter change on the system eigenvalues is highlighted.