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Helical armature

From Wikipedia, the free encyclopedia

A helical armature is a form of air-gap electric motor or generator armature wound in a helical fashion as opposed to a conventional random or orthocyclic winding. Such a design is of interest in superconducting motor and generation technology,[1] though comparatively little research has been done on the subject. An important and remarkable feature of helical armature windings is that they have no end windings.[2] Moreover, as each conductor follows a helical path of constant pitch, helical windings are not easily divided into active and end regions.[1] An important downside, though, is that such armatures provide poor winding factors.[3]

An illustration of a helically wound armature.

Use in motors

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Motors of helical armature design have a lower winding resistance, allowing the motor to run more efficiently, and giving it a longer lifespan.[2] Helical windings also provide low inertia and smooth torque for low-speed DC motors.[1] A disadvantage is that they have relatively low winding ratios.[3][2]

Use in generators

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An advantage of helical armature windings in superconducting generators is that they have higher VA ratings, lower armature resistance, and lower synchronous reactance.[3] Future superconducting generators would benefit from a helical winding because due to the absence of active and end zone it can be supported uniformly, unlike a conventional winding. There is a <10% loss in motor flux though, but this would be compensated for by the various advantages in this design.[1]

See also

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References

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  1. ^ a b c d Anderson, A.F.; Bumby, J.R.; Hassall, B.I. (1980). "Analysis of helical armature windings with particular reference to superconducting a.c. generators". IEE Proceedings C - Generation, Transmission and Distribution. 127 (3): 129. doi:10.1049/ip-c.1980.0024.
  2. ^ a b c Miller (2022-08-01). "Simulation Technology for Electromechanical Design : JMAG". www.jmag-international.com. Retrieved 2023-10-22.
  3. ^ a b c Kirtley, James L. (May 1995). "AIR-CORE ARMATURE SHAPE: A COMPARISON OF HELICAL AND STRAIGHT- WITH-END-TURNS WINDINGS". Electric Machines & Power Systems. 23 (3): 263–278. doi:10.1080/07313569508955622. ISSN 0731-356X.