Stability and robustness investigation of a modular system using a large-signal average model

Ensuring the stable points of a system is of great importance. In this paper, the stability analysis of a modular system is investigated using a large-signal average modeling. This is possible by determining the Jacobian matrix and then the system eigenvalues. The model for a two-module structure based on a three-level boost converter are applied. This studied structure is used with a controller to balance the voltages in the system. To implement the model, the equations of the system, including the stage power and the controller, are considered. It is also possible to study the robustness of the system when the system parameters are variable or uncertain. Simulation results using MATLAB/Simulink are presented. The robust properties of the system are investigated by studying the eigenvalues of the Jacobin matrix when the inductance and capacitance values change. It is observed that all eigenvalues have a negative real value. This ensures system stability for system parameters variations.