Flexible AC/DC Grids in Dymola/Modelica - Modeling and Simulation of Power Electronic Devices and Grids

Abstract: The research of the thesis was aimed towards investigating the possibility of implementing different control strategies for power electronic converters in a simulation environment. The different control modes were fitted into flexible models that were interconnected in various grid topologies. The software used in order to develop the simulation environment is called Dymola and presently does not include any form of control of power electronic units. The library used is the Modelica Electric Power Library (EPL) where some power electronic converters were already implemented. The grid was controlled and kept stable for various scenarios using the developed controlled converter models. The converter models were tested separately in order to verify that the models acted in the desired manner. The models where then interconnected into a grid and simulated for different scenarios in order to get grid models that could be fitted into multiple grid applications. To further prove this, models from external Modelica libraries were used in the grid setups. The results of the simulations clearly show that constructed models support the implementation of scalable and controllable grids in Dymola.