Development of a Novel Three-Phase Laminated-Core Variable Inductor for Var Compensation

This paper presents a novel three-phase laminated-core variable inductor made for the purpose of voltage stabilization in electric power systems. The proposed variable inductor has three-phase secondary ac windings together in one laminated-core to reduce the size and weight in comparison with the other single-phase ones. It can be applied as a var compensator since it can control the effective inductance of the secondary ac windings by dc excitation from the primary dc windings. First, the operating principle of the three-phase laminated-core variable inductor is described. Next, a trial 4.0 kVA variable inductor is designed based on reluctance network analysis (RNA), and then, the availability of the proposed variable inductor, which has good controllability and sinusoidal output current, is proved in experiments.