Overview

Motivated by the pressing changes witnessed by the electrical grid towards renewable energy generation, we consider power system stability and control as the main application of our theory. In particular, we apply our theoretical findings to study a network of power electronic inverters. We aim to find controllers that endows the inverters with an oscillatory behavior at a common desired frequency. In a closed-loop with these control strategies, inverters can be considered as nonlinear oscillators. Our study of the dynamics of nonlinear oscillator networks provides feasible conditions for a desirable operation. We can showcase the usefulness of inverse optimal control for the inverter-based generation to synthesize robust angle controllers with respect to common disturbances in the grid and provable stability guarantees. All the controllers aim to provide the electrical grid with important services, namely power support whenever needed, as well as power-sharing among all inverters. 

See also: Popular summary: https://drive.google.com/file/d/1j8HnqTXf5fNld6otNM0WnJ-O2N3hbCsE/view?usp=sharing

PhD defense: drive.google.com/file/d/1gZaExMpQl0NNtq_zTwgM-P3rd6EHBqEo/view 

Test and validation of inverse optimal controllers for power systems

In [J4], [C5], we design inverse (robust) optimal angle controllers for inverter-based power generation that make use of power measurements to drive the converter's angles towards desired frequency synchronous steady states. They are the unique optimal controllers that guarantee local stability of the multi-inverter system. 

Following our numerical simulations, we are conducting real-life hardware experiments in the Energy Laboratory 2.0 located in the north campus of Karlsruhe Institute of Technology (KIT). The laboratory is a fully automated and user-oriented research infrastructure for controlling and operating smart energy systems in the context of a microgrid-under-test setting and enjoys a high level of automation and capacity to fully function in an islanded mode. The experimental setting allows for the test and validation of our angle controllers in a safe environment.  A summary of our current progress is given below.