Modern Control Method of MMC STATCOM for Future Power Grids

Nowadays, renewable energies are fed into the grid via converter systems. Compared to conventional feed-in via synchronous generators, which exhibit the behavior of a controlled voltage source, converter-based systems behave like a controlled current source. This is primarily accounted to the control algorithms that are implemented in the converter systems and require a significant change in the energy transition. Essential grid functionalities are currently covered by conventional power plants, which are reliable and constantly connected to the grid but must be substituted by renewable energy sources in the long term to comply with the requirements of the energy transition. In order to evaluate a modern control method, a DFT-based control method is used as a basis and afterwards implemented on a conventional MMC STATCOM. Based on this model, the performance is investigated and discussed by means of simulation in the course of the paper.