Homopolar Generator

(redirected from Homopolar disc dynamo)

homopolar generator

[¦hä·mə′pō·lər ′jen·ə‚rād·ər]
A direct-current generator in which the poles presented to the armature are all of the same polarity, so that the voltage generated in active conductors has the same polarity at all times; a pure direct current is thus produced, without commutation. Also known as acyclic machine; homopolar machine; unipolar machine.

Homopolar Generator


(also acyclic machine), a direct-current generator without a commutator that operates on the basis of homopolar induction.

In a homopolar generator, two toroidal field coils are located on the stator and are wound coaxially with the shaft (Figure 1). The coils produce a constant magnetic flux in an annular air gap between the stator and the armature. In the simplest case, the current is collected directly from the lateral surface of the armature, which is a solid metallic cylinder or disk, by moving brushes. In more complicated designs, the moving and stationary components of the current-collecting assembly are separated by a layer of liquid metal.

Figure 1. Schematic diagram of a homopolar generator: (1) field windings, (2) current-collecting assembly, (3) stator, (4) armature, (5) axis of rotation of the generator shaft, (6) external load, (7) magnetic lines of force of the field coils. The minus sign and the plus sign indicate the direction of the current in the coils (out of the page and into the page, respectively).

Homopolar generators are used mainly to obtain high currents (~104–105 amperes) at low voltages (~1–10 volts). The advantages of such generators include a reliable and simple design, a relatively small size, and high thermal and dynamic stability. The current produced by the generators does not pulsate.

Homopolar generators are employed as the power supplies of, for example, high-power electrolysis equipment, arc furnaces, electromagnetic pumps for liquid metals, and DC electromagnets.


Bertinov, A. I., B. L. Alievskii, and S. R. Troitskii. Unipoliarnyeelektricheskie mashiny s zhidkometallicheskim tokos”emom. Moscow-Leningrad, 1966.


References in periodicals archive ?
Moroz, "Synchronization and electronic circuit application of hidden hyperchaos in a four-dimensional self-exciting homopolar disc dynamo without equilibria," Complexity, vol.
Zhang, "Hidden hyperchaos and electronic circuit application in a 5D self-exciting homopolar disc dynamo," Chaos: An Interdisciplinary Journal of Nonlinear Science, vol.
In 1979, Moffatt identified inconsistencies in the modeling of a simple self-exciting homopolar disc dynamo because of the neglect of induced azimuthal eddy currents, which can be resolved by introducing a segmented disc dynamo [10].
Current interest in hidden hyperchaotic attractors motivates us to study an extension about the self-exciting homopolar disc dynamo [10] to 4D homopolar dynamo without equilibria.
There seems to be two equilibria: [E.sub.1](1/[square root of m], 0, 0, r/[square root of -m]) and [E.sub.2](-1/[square root of -m], 0,0, -r/[square root of -m]); however, because m is positive, hyperchaotic self-exciting homopolar disc dynamo system (2) has no real equilibria.
Synchronization of the 4D Self-Exciting Homopolar Disc Dynamo System
For synchronization, two self-exciting homopolar disc dynamo hyperchaotic systems are coupled together with different initial values.
Figure 4 shows that both active and sliding mode controllers achieve the synchronization of the four-dimensional self-exciting homopolar disc dynamo hyperchaotic system.
Electronic Circuit Implementation of the 4D Self-Exciting Homopolar Disc Dynamo System
In this paper, we propose a novel four-dimensional self-exciting homopolar disc dynamo without equilibria, but exhibiting hidden hyperchaos.
Caption: Figure 3: Hyperchaotic attractor of four-dimensional self-exciting homopolar disc dynamo system (2) without equilibria for r = 8, g = 35, k = 3, and m = 0.5.
Caption: Figure 4: Time series of driver and response four-dimensional self-exciting homopolar disc dynamo hyperchaotic systems with the controllers are activated at t = 10.