A newly developed colloidal magnetic fluid (MF) has been investigated for u
se as high-voltage insulation. Being a liquid magnet, MF interacts with the
magnetic field of transformer windings and improves their cooling, while a
t the same time MF increases the lightning impulse withstand voltage and de
creases the discharge propagation velocity, probably due to an enhanced ele
ctric field dissipation due to the presence of magnetite nanoparticles. (C)
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