Comparison between ARISTO and DIgSILENT Power Factory

Abstract: Voltage stability is an important issue in electrical power system. As a result, several industrial-grade power system simulator tools are developed in order to estimate the behaviour of the electric power system under certain conditions. Several tests have been developed to compare and to check different simulators and to prove their correct performance. Comparisons between commercial simulation tools as PSS/E, PowerFactory, SIMPOW, EUROSTAG have already been made but comparisons with ARISTO have not been found. The aim of this thesis is to compare ARISTO with the more widespread simulator DIgSILENT PowerFactory. The tools employ different models, components, analytical and numerical algorithms; therefore, different result can be expected for the same benchmark system. One important reason for this is that ARISTO must prioritize realtime performance. The project is carried out in two different parts. The first part describes the differences found between the simulators and the tests executed to find these. The second part checks how these differences affect the result in small and large systems to find out how significant they are in practice. The different studies use smaller benchmark systems from Kundur book(1994) and the Swedish test system Nordic 32. Short term and long term dynamic simulations are run to test different aspects in the simulator. It is concluded that in general, ARISTO performs well and simulation results are mostly close to those of PowerFactory. However, there are many issues that must be taken in account. Most important are modelling differences like damping factor and the lack of subtransient reactance definition. For general studies, the limited flexibility in defining component models in ARISTO must be considered. In this work the flexibility in modelling in PowerFactory has been used to build models like the fixed ones in ARISTO. In addition to this a few issues that seem like software bugs have been identified in release 4.4.1.