By using an orthogonal-core-type variable inductor and capacitor, we will realize a simple, reliable, and high-quality voltage regulator. However, the nonlinear magnetization characteristic of the orthogonal core causes harmonics in the output current. To reduce the harmonic current of the orthogonal-core-type variable inductor, we previously proposed an orthogonal core with wedge gaps. A 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. For wide application, it is necessary to examine the optimum size of the wedge gap and to establish a design method for the orthogonal core. In this paper, we present a method for quantitative analysis of the orthogonal core with wedge gaps, and examine the characteristics of the variable inductor for various dimensions of the wedge gap.
