Modeling, Small-Signal Stability Analyzing and Implementing of an Inverter-based Distributed Generation with Feed-forwarded Model Predictive Controller

Abstract

Nowadays the control and stability of DG systems are important topics that researchers in both academia and industry. Small and large signal analyses for stability studies on various systems have been done in papers and books. In this paper, first models of an inverter-based Distributed Generation (DG) subsystems are created. After the linearization, if required, the small-signal stability analysis of the DG which is controlled with a voltage and frequency control scheme based on the model predictive control (MPC) that has been used previously, is established. In this control scheme, load currents at the point of common coupling (PCC) of the DG are considered as disturbances and used as feed-forward signals. This technique enhances the performance of the DG control system in transient and steady-state conditions for a wide range of loads. The stability of the DG system under various loads (such as one phase load as imbalanced load, rectifier load as nonlinear load and induction motor load as dynamic load) is demonstrated by the eigenvalues trajectory. The sensitivity analysis and robustness assessment of the control scheme are also conducted and discussed. For more performance consideration, the DG system is simulated with MATLAB/SIMULINK software, implemented in the lab and later the suitable performance of the system is demonstrated by the simulation and experimental studies.