Public defence in Power Electronics and Electric Drives, M.Sc. Bahram Pournazarian

M.Sc. Bahram Pournazarian will defend the thesis "Artificial Intelligence-based Control Methods for Optimal and Stable Operation of Converter-dominated Microgrids" on 31 March 2023 at 12 (EET) in Aalto University School of Electrical Engineering, Department of Electrical Engineering and Automation, in lecture hall TU1, Maarintie 8, Espoo.

Opponent: Prof. Marco Liserre, Christian-Albrechts-Universität zu Kiel, Germany
Custos: Prof. Edris Pouresmaeil, Aalto University School of Electrical Engineering, Department of Electrical Engineering and Automation

Thesis available for public display 10 days prior to the defence at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/
Doctoral theses in the School of Electrical Engineering: https://aaltodoc.aalto.fi/handle/123456789/53

Public defence announcement:

The global warming, energy crises and ever-increasing demand for electricity necessitates the integration of renewable energies into future smart grids. The microgrid as the key building block of future smart grids is prone to converter instability, frequency instability, and unfair reactive power sharing because of the lack of intrinsic inertia and infinite bus, frequency and voltage coupling, and high sensitivity to disturbances. These challenges could be extended to the main grid and jeopardize the stability of power system.

Hence, this doctoral dissertation spotlights on two main converter control methods in microgrids (i.e., droop control and VSG control) and provides novel strategies to ensure the microgrid small-signal stability at all operating points, frequency stability, fair reactive power sharing, and favorable dynamic performance.

The main elements of this interdisciplinary research include microgrids modeling, stability analysis, metaheuristic optimization methods (i.e., PSO) and artificial intelligence (i.e., ANFIS). Two main control schemes, i.e., optimization approaches for droop-based microgrids, and optimization approaches for VSG-based microgrids, are developed aiming to ensure converter stability, advanced dynamic response, and frequency stability of power electronics-based microgrids.

The following main contributions are made to the research field of mcrogrids control: (1) the proposed PSO-based droop control, unlike the basic method, allows the microgrid stability at all operating points, fair reactive power sharing and enhanced dynamic response. And, (2) the proposed PSO-based VSG control offers a favorable dynamic response, microgrid stability, and frequency stability.

The results of this dissertation cover a wide range of applications including the integration of renewable energy resources e.g. solar and wind power plants into converter-dominated AC microgrids and also in individual islanded microgrids such as cruise ships.

Contact information of doctoral candidate: