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

Abstract

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.Index Terms-Reluctance network analysis (RNA), three-phase laminated-core variable inductor, var compensator.

Iron Loss Calculation for Concentric-Winding Type Three-Phase Variable Inductor based on Reluctance Network Analysis

“…To resolve the above problem, a three-phase variable inductor was presented in a previous paper 5) . It has only one laminated-core in which three-phase secondary ac windings are installed together.…”

Three‐phase EU orthogonal‐core variable inductor

“…One three‐phase laminated‐core variable inductor was proposed in Ref. . It has linear controllability and sinusoidal output current.…”

Design for size and weight reduction of lap-winding type three-phase variable inductor

“…Figure 9 shows the shape and dimensions of the previous three-phase variable inductor. 6 It is understood from Figs. 7 and 9 that the core diameter of the proposed variable inductor can be reduced by about 6% in comparison with the previous threephase variable inductor.…”

“…1(a) was proposed. 6 It has only one laminated-core in which the three-phase secondary ac windings N u , N v , and N w are installed together. A trial 4.0 kVA three-phase variable inductor was prototyped and exhibited good controllability and sinusoidal output current.…”

“…Figure 2(a) shows the shape and dimensions of the core which are the same as those of the trial variable inductor described in Ref. 6. To obtain the sinusoidal ac current, the flux density of the leg should be less than the saturation magnetic flux density.…”