A suitable to the microgrid analysis approach for nonlinear modeling and control of an inverter interface

• Main Authors: Papageorgiou, Panos C., Alexandridis, Antonio T.
• Format: Conference Proceeding
• Language: English
• Subjects: Impedance; Inverters; Microgrids; Power conversion; Power system stability; Stability analysis
• ISSN: 2473-3504
• DOI: 10.1109/MED.2017.7984170

Distributed generation and smart grids in modern power systems have as basic building block a microgrid structure which is naturally an electric network with nodes and links. However, since a microgrid is an active network, in most of its nodes, different distributed generation units are usually connected through a power inverter interface. Thus, for the entire analysis and control of a microgrid, the deployment of a suitable model is needed that can certainly take into account the dynamic behavior of the power inverter devices. In the paper, it is shown that such a modeling for the inverter interface can be implemented by using a systematic impedance-admittance description. It is also shown that this formulation results in a nonlinear modeling, absolutely compatible with the rest microgrid description. Also, it is further proven that suitable model-based local current-loop control schemes, such as proportional-integral (PI) or simply proportional (P), can be effectively applied to stabilize the power electronic devices at their equilibrium. For the analysis purposes, a rigorous nonlinear Lyapunov-based method, with the control schemes included, is deployed to guarantee stability, firstly as input-to-state stability (ISS) and in a second stage as convergence to the equilibrium.