Development of 3-phase 100 kVA orthogonal-core type variable inductor with sinusoidal output

This paper presents a three-phase variable inductor for reactive power control in an electric power system. The variable inductor is constructed with three orthogonal-cores, and is controlled by a simple dc-dc converter. In order to reduce the harmonic currents of the variable inductor, we made a partial gap in the orthogonal-core. The trial three-phase 100 kVA variable inductor demonstrates that the variable inductor can be put to practical use in a 6.6 kV ac distribution system.