Development of an efficient distribution transformer using amorphous core and vegetable insulating oil

This paper presents the development of an efficient distribution transformer, based on amorphous core and vegetable insulating oil. Significant reduction was obtained in no load losses and guaranteed operation in higher temperatures, along with the fact that the fluid is non-toxic and of fast biodegradation. A distribution transformer design methodology considering the total cost of the equipment is displayed. In this methodology, design parameters, such as induction, number of turns (volts/turn), current density and the aspect ratio of coil form are varied in order to find the best transformer design. Simulation tools of Computational Fluid Dynamics (CFD) using Finite Volume Method (FVM) were applied aiming at proposing innovations to the cooler system taking into account the characteristics of viscosity of the vegetable oil. As result, was developed a prototype unit of 75 kVA, voltage class of 15 kV, primary voltages of 13,800/13,200/12,600 V and secondary voltages of 380/220 V, amorphous core, aluminum wires and vegetable insulating oil.