Abstract: A system includes conductive windings extending around a magnetic core and impedance-varying windings extending around the magnetic core. The impedance-varying windings include positive windings and negative windings. The conductive windings and the impedance-varying windings conduct electric current around the magnetic core. The system includes a first impedance tap changer that is electrically coupled with the positive windings of the impedance-varying windings and a second impedance tap changer electrically coupled with the negative windings of the impedance-varying windings. A controller controls the first impedance tap changer and the second impedance tap changer to change an impedance of the system by changing which portion of the positive windings and which portion of the negative windings are conductively coupled with the conductive windings, and which portion of the positive windings and which portion of the negative windings are disconnected from the conductive windings.

Abstract: A dielectric fluid composition containing of 60% to 63% in weight of mono-unsaturated fatty acid, of 20% to 23% in weight of di-unsaturated fatty acid, of 5% to 7% in weight of tri-unsaturated fatty acid, and of 6% to 8% in weight of saturated fatty acid, such that the dielectric fluid is free of antioxidants and/or external additives and has the following properties: a dielectric strength of 40 kV to 70 kV at a separation of 2 mm, a dielectric constant of 2.5 to 3.1 at 25° C., and a dissipation factor of 0.05% to 0.15% at 25° C. The dielectric fluid composition can be obtained by a combination of 95.5% to 99.25% in weight of at least one high oleic vegetable oil, of 0.25% to 1.5% in weight of grape seed oil, of 0.25% to 1.5% in weight of sesame seed oil, and of 0.25% to 1.5% in weight of rice bran oil.