Power quality improvement by use of a solid state current limiting device

This paper presents a case study investigating voltage dip problems in the distribution system in a steel plant. It is shown that an increase of the short-circuit capacity on a 10 kV bus by reconnecting a generator will reduce the plant's vulnerability to the disturbances. The short-circuit currents, which otherwise would be too large, can be limited with a solid state current limiter. Different cases of faults and disturbances have been simulated in the simulation program EMTDC. The simulation results presented show the functions and rating needed from the current limiter as well as the improvements in power quality which would be achieved by the use of the device.