A Generic Architecture for Robust Automatic Detection and Suppression of Sub-Harmonics

Sub-harmonic phenomena become a critical issue as properties of the power grid change. In this paper we propose a generic architecture to detect and suppress these sub-harmonics automatically in a robust way. Therefore different algorithms to analyse the signals from the power grid, like wavelet-and prony analysis, are used and extended to rate and incorporate signal quality. The results of these algorithms are dynamically fused using according to their trustworthiness in order to achieve a detection as robust as possible. Afterwards the intervention needed to suppress a detected sub-harmonic is determined and applied by remote load management in our case. First experimental results show the validity of this trustworthiness-based architecture. 1 Motivation Today's power grid is subject to impressive changes. The characteristics of generation, distribution and consumption of electrical power have changed a lot and will change a lot more in the future. The installation of many renewable energy sources in favour of singular big power plants and the resulting distributed power generation is the major issue. Along with it come increased, uncontrollable dynamics in the amount of power that is generated and a multi directional energy flow. The uncontrollability is caused by the fact that it is not possible to influence the primary energy sources of renewable energies, like wind and light, effectively. Also the power consumption changes: For example the upcoming e-mobility adds a non-trivial amount of rechargeable batteries to the grid. The amount of other non-linear loads like switch-mode power supplies and LED-light rises to an extend, which is no longer negligible. On the other hand, more and more components of the grid can be controlled directly by remote load management (RLM) and by techniques like demand side management (DSM). Thus the (inner) dynamics of the power grid get excessively complicated. All this leads to a high uncertainty about the system under control. Beyond the energy flow level, severe problems concerning power quality arise: The increased amount of harmonic, inter-harmonic distortions and sub-harmonic stability issues cause a significant danger to components of the grid, endangers the overall stability, and 1455