Combined, experimental data supported simulations in development of power grid impedance identification methods

The development of invasive methods for power grid investigations is not easy as has to be made in comfortable conditions (laboratory equipped with instrumentation and enough computing power), while grid signals and experiments are accessible in field conditions. Ad hock planned invasive experiments during research development are dangerous to the power system and the software/hardware developer. The paper is focused on development of invasive methods of grid impedance determination with the use of experiment data supported simulations. Simulations form standard tool replacing difficult to access reality, however can not deliver enough detailed description of signals which exist in real power grids, and which affect impedance identification/determination DSP. In the paper the combined method for generating valuable signals, which describe the excited real grid, is proposed. The method needs passive (non-invasive) grid observations and enriches them with testing signals of the simulated grid. In such the approach the simulations are responsible only for impedance information, while observations deliver full information on the real grid signal properties. The usefulness of the method for impedance devoted DSP improvement was illustrated with the examples of a grid exciter development.