Magnetic Integration Technology in Controllable Reactor of Transformer Type Constituted by Various Magnetic Materials

Abstract

Eliminating the magnetic coupling among control windings and simplifying the complicated structure caused by current-limiting inductance cascading in the control winding circuit of a controllable reactor of transformer type (CRT) are quite important. Based on the technology of magnetic integration, a magnetic integration structure composed by a variety of magnetic materials is proposed. The formulas for short-circuit impedance and short-circuit current of each winding are deduced by the establishment of the equivalent circuit and are then verified by an example. The results of the calculation example show that the structure cannot only integrates control winding and current-limiting inductance but can also weaken the magnetic coupling among control windings; therefore, the structure meets the requirement of “high impedance” and “weak coupling.” Thus, the whole structure of CRT is simplified, and the no-load current is reduced. It can be drawn that the magnetic integration structure constituted by various magnetic materials could provide useful reference for the magnetic integration of similar multi winding electromagnetic equipment.