Simulation of resonance in a small-scale network laboratory

The department of Electric Power Engineering at the Tampere University of Technology (Finland) has a project for reducing problems caused by harmonics, using a small-scale industrial network laboratory. There it is possible to investigate phenomena which take place in the industrial network. The laboratory consists of motors and other components that can be found in real networks. For harmonic filtering, there is a fifth harmonic filter with two steps. The harmonic filter produces basic frequency reactive power that can be used to compensate the reactive power needed by the laboratory, and to study the effects of the reactive power. The components of the laboratory have been modeled with PSCAD-EMTDC program. The aim of this paper is to present simulations, using the PSCAD-EMTDC program and the laboratory, how the capacitors for reactive power compensation can build up a series resonance circuit for some harmonics. The results of the simulation and laboratory studies are quite similar.