Magnetic Nanofluid Applications in Electrical Engineering

This paper presents a superparamagnetic nanofluid (SMP-NF) and three of its applications. The SPM-NF particles were suspended in oleic acid as surfactant, and then dispersed in UTR 40 transformer oil (TO). The average particle size obtained from X-ray diffraction is 14 nm, and from scanning electron microscopy is between 10 and 30 nm. The magnetic measurements for the oleic-oil transformer acid-magnetite nanoparticles of 27 nm diameter in size and 9.78×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">25</sup> nanoparticles/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> particle density system provide for specific saturation magnetization, Ms. The volume fraction is 1.1% and the magnetization is 62 Gs. The SPM-NF may be designed to be used either as coolant or as magnetic medium in three electrotechnic devices: a power electric transformer TMOf 2-36 kV-40 kVA, at 50 Hz, a microactuator that implements the pulse width modulation (PWM) principle, and in miniature planar spiral transformers, for galvanic separation or step-up/step-down conversion. The paper presents experimental and numerical simulation results that confirm that the SPM-NF usage open new venues in optimizing conventional electrotechnic constructions or to design novel devices.