Modelling different scenarios of Virtual Power Plant operating possibilities

This paper compares various models of steering strategies for a portfolio of Distributed Energy Resources (DER). Virtual Power Plant (VPP) is a flexible representation of such a portfolio, and one of its key assignments is to guide each DER in order to dispatch desirable active power. Portfolio includes two controllable synchronous generators (CHP), two wind turbines, ten photovoltaic plants and a fuel cell turbine. Stochastic nature of load demand and output power from renewable energy resources is taken into account. An algorithm was developed, based upon active power requests for VPP, weather conditions and expected consumer loading, which optimizes dispatch of controllable generators in order to track the production of intermittent sources and in that way make VPP wanted output. Simulations were carried out on a real distribution network (Sopot, part of Zagreb) through one usual consumption day comparing three scenarios of VPP controllability and investigating the best scenario either for the Distribution System Operator (DSO), either for VPP. Results demonstrate that the algorithm is able to efficiently control the portfolio and, based upon the primary requirements for VPP, either to maximize reduction of total losses in the distribution network, to cut off the peak demand from external grid, or to produce constant power through whole day.