Modeling of An Enhanced Three-phase Continuously Variable Reactor

The traditional technology of magnetic amplifier, where a DC bias controls the saturation of a ferromagnetic core, has recently received increased attention from power system engineers. Possible applications have been considered for addressing different problems in the power system. Still, there has not been much work toward the improvement and modification of the original design according to the system needs. This paper presents a three-phase variant of the magnetic amplifier-based continuously variable series reactor (CVSR) with improved reactance modeling. A magnetic equivalent circuit (MEC), a computationally efficient yet sufficiently accurate analytical circuit for the CVSR is presented. The accuracy of the MEC is validated by comparing the average differential inductance from the MEC with the one obtained from a 3-D finite element analysis (FEA) model of the reactor for a range of DC bias current variations. In addition, a heterogeneous ferromagnetic core material mix is proposed to improve the reactance characteristic of the CVSR for smoother and better control.