Integration of active power-controlled photovoltaic energy sources in distribution grids by dynamic virtual power plants

Active Distribution Grids are becoming more and more important during the increasing amount of renewable resource in power systems. As most renewable generation plants are integrated into the distribution grids and with the goal of up to 100 percent renewable energies for electricity generation, they must contribute active to grid forming and stabilization. Addressing this task, an optimal nonlinear model reference decentralized controller design is presented in which the control objectives in a distribution grid are determined using an aggregated reference model, which is then decomposed into partial reference models for the controller design of individual generation units. For this purpose, a model reference controller synthesis for control-oriented models polytopic models is proposed. It is demonstrated how this approach takes into account the non-linearities in the design for fast frequency reserve by photovoltaic systems over a large operating range due to large active power adjustment. Using a benchmark of the IEEE 13 node test feeder network with an extension of four integrated photovoltaic generation units, the frequency control and stabilization from an active distribution network for a transmission network is investigated.