News | Published:


    Naturevolume 150page695 (1942) | Download Citation



    A PAPER by E. Friedlander (J. lust. Elec. Eng., 89, Pt. 2, No. 11 ; October 1942) discusses the theory of this subject, pointing out that the security of the windings of an alternator generating at 22 kv. or above and connected directly to a network depends mainly on the ability of the insulation to withstand surge voltages. The distribution of surge voltages in the various types of stator winding hitherto adopted in commercial practice is examined, together with the relation of this distribution to that of the effective insulation available. As alternators nearly always operate with the neutral point of the windings unearthed, the voltage stresses on the insulation near the neutral in these circumstances are determined, and the danger of the use of graded insulation is discussed. In no case does there appear to be an inherent tendency for all transient voltages to be distributed over the length of the stator winding in the same proportion as the generated voltage of the machine.

    About this article

    Publication history

    Issue Date


    Further reading


    By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

    Newsletter Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing