Simulation study of a "Smart Grid" approach: Model reduction, reactive power control

Distribution grids evolve more and more to so called “Smart Grids” with a decentralized structure. New information and communication technologies (ICT) to manage these “Smart Grids” are necessary to integrate a high share of renewable energy systems. Due to a high number of system components the optimal operation and control of “Smart Grids” is highly complex which is why this paper uses the approach of symbolic reduction to derive models with lower order for grid segments. Symbolic model reduction is a technique that analyses a set of equations and removes eqautions that do not influence the specified variables. The simulation study on a typical distribution grid shows a reduction by the factor of 2. The method of symbolic reduction has been applied to several sub grids of the CIGRE benchmark grid a typical distribution grid. Local control strategies for feeding reactive power have been implemented for 10 cogeneration plants. Results show that the spread and the absolute value of the voltage band in the CIGRE grid decrease. This offers further degrees of freedom for the grid operation and further distributed generators can be connected.