Modeling and Harmonic Damping Effect of Shunt Active Filters for Dispersive Installation on Power Distribution Systems

With significant development of power electronics technology, the proliferation of non-linear loads such as static power converters in a range of 50W to 300MW has deteriorated power quality in transmission/distribution systems. Notably, voltage distortion or voltage harmonics may approach or exceed its allowable level in power distribution systems. Individual electric power consumers and end-users are responsible for reducing current harmonics, while electric power companies or utilities are responsible for reducing voltage harmonics at the point of common coupling in distribution systems. Dispersive installation of shunt active filters on power distribution systems is a viable and effective way of solving “harmonic pollution.” The main objective of this paper is to develop a model for the shunt active filters, and to show how well the shunt active filters are effective in damping of harmonic propagation, much attention being paid to site selection. The system analysis concludes that a shunt active filter based on voltage detection has the capability of harmonic damping throughout a feeder, and that a shunt active filter based on supply current detection with differential compensation is suitable, not for harmonic damping, but for harmonic compensation of one or more non-linear loads. This paper discusses two shunt active filters based on voltage detection, which are dispersively installed on both end terminals of two feeders in a distribution system. Computer simulation verifies the validity of the modeling and harmonic damping effect of the shunt active filters for dispersive installation on power distribution systems.