Generator Model Extension for Higher Accuracy Simulation of Power System Transients in OpenModelica

Mathematical modeling is a key step in the analysis of power system stability. In view of model accuracy, this process should include all relevant details that affect the transient behavior of the power system and hence influence the electrical and mechanical torques in the system. To this aim, this paper describes the extension of the generator subsystem model details in OpenModelica by adding a turbine-governor model to the existing generator subsystem. Taking advantage of the multi-domain modeling property of OpenModelica, two libraries are coupled to interconnect the mechanical and electrical domains of the generator subsystem. The new generator subsystem is beneficially tested using the standard IEEE 9-Bus test feeder by comparing its response to network disturbances to that of the previously existing OpenModelica generator model. The simulation results in OpenModelica are furthermore successfully compared to respective results in DIgSILENT PowerFactory. Hence, the new generator subsystem model is integrated into the validated 20 kV power grid model of Campus North of Karlsruhe Institute of Technology and respective results are presented for abrupt load changes.