Research On Digital/physical Hybrid Simulation System Of Distributed Generation

In recent years, since energy dilemma and environmental pollution areincreasingly serious, countries are research on distributed generation technology ofnew energy sources actively. The technology can significantly improve utilizationrate of primary energy and reduce exhaust gas emissions, but also brings newchallenges to operation and management of the traditional power grid. Thegrid-connected operational control, interaction with the grid and dispatchingmanagement is the basic research subject of distributed generation. At present, themain research techniques to the above subject are physical simulation and digitalsimulation. Physical simulation has clear physical meaning, but limited by thesimulation scale and experimental conditions, it cannot fully study the actualsystem, and it’s simulation variety is poor. Digital simulation is not restricted by theresearch object scale and structure complexity, but the simulation accuracy is nobetter than physical simulation, and can’t simulate physical phenomenas which aredifficult to be described in mathematical expressions. Digital/Physical hybridsimulation which is combined with the physical simulation and digital simulationbrings a new idea to research distributed power generation technology, andbecomes a new focus in power system research. According to the different subjects,the digital/physical hybrid simulation structure can be flexible adjust. For somesubsystems or components whose internal running mechanism are not clear or aredifficult to be described by mathematical expressions, can be replaced with physicalmodels. This greatly expanded the research scope of digital/physical hybridsimulation.This paper proposed a design scheme of digital/physical hybrid simulationsystem based on NI-PXI for study of the related technologies of distributedgeneration. First of all, make a numerical stability analysis for a simple circuit anddiscusses the basic requirements of the scheme on the interface algorithm andparameters. And then focuses on the key equipment of digital/physical hybridsimulation, power interface device. In order to achieve the fast and stable control ofthe DC voltage of power interface device, a current predictive control strategy isproposed. On the basis of the above-mentioned study, actual digital/physical hybridsimulation system is constructed. And two digital/physical hybrid simulationexperiments on the power control of wind power generation system andphotovoltaic generation system were carried out. The simulation results show thatthe scheme is feasible, universal and suitable for studying the operation and controlof DG and its interaction with grid.