Eine unipolarmaschine auch als unipolargenerator, homopolarmaschine oder. This type of motor converts electrical energy into mechanical energy using the lorentz force. Homopolar generators homopolar generator up to 24kv 10a permanent. Energies free fulltext superconducting ac homopolar. Wright j c, price j h and gully j h 1993 preliminary design of a 1 gj homopolar generator ieee trans. The selfexcited aircored homopolar generator is shown to be an ideal power source for an electromagnetic railgun. A homopolar generator is a dc electrical generator comprising an electrically conductive disc or cylinder rotating in a plane perpendicular to a uniform static.
Generator 10 comprises a rotor 12 mounted to a shaft 15 journaled in bearing assemblies 17 and 18 for rotation within a casing 20. A homopolar generator is a type of electrical generator that produces direct current dc using an electrically conductive disc that rotates within a static magnetic field. It is capable of high overall efficiency, typically 40 percent for the complete system generator and railgun, and gives an acceptably low peakmean acceleration in the barrel. Generator design software free download generator design top 4 download offers free software downloads for windows, mac, ios and android computers and mobile devices. General atomics to design and fabricate advanced propulsion. Producing direct current, the generators polarity hinges on the discs direction. Homopolar motors and generators are simpler than their multipolar cousins see electric motors and generators, but are very rarely used in practice. Jul 10, 2009 the one in make is not homopolar, it is, as windell oskay put in in the comments below. This field profile is produced by a unique arrangement of coils that creates a high drive field for the rotor and a low field regions for the field critical lmcc. How to build a faraday homopolar device the green optimistic. Study of homopolar dc generator a thesis submitted to the university of manchester for the degree of doctor of philosophy in the faculty of engineering and physical. Performance of twinrotor dc homopolar motor semantic scholar.
A synchronous homopolar machine for highspeed applications. A general theory of homopolar generator design is given, including estimation of brush friction loss and conditions for stable operation when conducting large currents. Disc permanent magnet as homopolar generator stack exchange. This new pm motor software utilizes both finite element fe and analytical. Pdf modelling and simulation of a simple homopolar motor of. The disc is held stationary while the magnet is spun on its axis.
Electric generator design software quickfield fea software. A superconducting homopolar motor and generatornew approaches. Pdf a superconducting homopolar motor and generator new. Homopolar generators homopolar generator up to 24kv 10a permanent current. The disc is at a right angle to the magnetic field, so its rotation creates an electrical potential difference between the center of the disc and its rim. Simulation of resonances in the homopolar generator. Machines of this kind were in use until about 1900 but were replaced by modern induction motors and generators. The advantages of such generators include a reliable and simple design, a relatively small size, and high thermal and dynamic stability. The design, construction, and operating characteristics of a homopolar motor are described in this thesis using both physical experimentation and simulation software. It was the beginning of modern dynamos that is, electrical generators which operate using a magnetic field.
A tabulated survey of the principal ohmic losses and power absorbed by brush friction is given for a 10kw generator. The faraday disk is one of the primitive homopolar generator design which enabled faraday to establish the foundations of the electromagnetic theorem we still use in our modern days. Jun 14, 20 the apparatus therefore acts as a generator, variously called the faraday generator, the faraday disc, or the homopolar or unipolar generator. Inexpensive inertial energy storage utilizing homopolar motor.
Many roads and bridges are in need of long overdue repairs. In both cases mopolar generators, many design solutions were developed 1524 fig. Fem software codes comsol multiphysics including the integrated spice. See the comments for more info and links to a some other homopolar motor projects and info. New lower cost homopolar generator design developed for. Homopolar generators, however, are modeled in equivalent circuits as lowvoltage capacitors. So, a homopolar generator is really simple, at least in concept. Homopolar generators article about homopolar generators by. Homopolar generator a homopolar generator is a dc electrical generator comprising an electrically conductive disc or cylinder rotating in a plane perpendicular to. You should check out what happened to the concept in the wikipedia article on it.
The cell provides current that flows through one brush to the central shaft, then outwards to the right towards the brush on the rim. Homopolar generators unanswered questions and design details free energy searching for free energy and discussing free energy. Although there have been many experimental approaches to. Ac homopolar synchronous machines are an ideal choice for such applications as these machines enable very high rotational frequencies. The potential of homopolargenerator welding the fabricator. A homopolar generator has one source of an electromagnetic field, which spans from the center of a spinning disc to the rim. The disc is at a right angle to the magnetic field, so its rotation creates an electrical potential difference between the. However, they illustrate the principles nicely, and a homopolar motor is both easy to make and easy to understand. They were first invented in the 1800s and have no significant practical application today, but can be useful for the demonstration or. Figure 2 is an electrical and mechanical schematic of the generator system incorporating generator 10. One of the earliest patents on the general type of homopolar generators was attained by charles e. Whatisanhpg faradaydiskorwheel simpledcelectricalgenerator operavonalbasics. A homopolar motor is a simple electric motor with two magnetic poles. The same is also true when applied to a motor the electrical polarity changes since now electricity is supplied to the motor.
Unconventional construction of the brushless homopolar. Brown university authentication for webbased services. I recently realized that i do not truly understand how a faraday disc i use this spelling on purpose. Figure 1 is a sectioned isometric view showing a homopolar generator according to the present invention. I am getting on in years so i apologize that my mind may not be working as well isould lie it to.
Oh that faraday disc is referred to as a homopolar generator, and its quite interesting. The torque from this force is used to propel the homopolar motor forward. In a simple design for a very simple homopolar motor, the magnet. Generator design software free download generator design. Relatively small homopolar generators store energy equivalent to that stored in large capacitors charged to several thousand volts. Pulsed homopolar generator hpg power supplies are well suited for driving the singleturn coils of the ignitex fusion experiment1 because they are inherently low voltage dc machines capable of high output currents. The one in make is not homopolar, it is, as windell oskay put in in the comments below.
The equivalent capacitance of a homopolar generator is determined with the equation 2ev. Jan 22, 2016 homopolar generator a homopolar generator is a dc electrical generator comprising an electrically conductive disc or cylinder rotating in a plane perpendicular to a uniform static magnetic field. Apr 09, 2018 to continue this work, you can evaluate the performance of homopolar generator designs using the comsol multiphysics software. Modelling and simulation of a simple homopolar motor of. Homopolar generators unanswered questions and design details. The university of texas at austin center for electromechanics utcem has recently developed a new lowercost homopolar generator design that could help. Multiphysics software was used to optimise the coil design and analyse the motors performance. The apparatus therefore acts as a generator, variously called the faraday generator, the faraday disc, or the homopolar or unipolar generator. Design of a homopolar generator power supply system for the. Basic operation of an hpg is voltage generation across a conductive disk or drum rotating in 1 steady magnetic field. It is frequently called the faraday disc or faraday wheel in his honor. Quickfield is efficient electric generator design software and you may find more information and examples about this here. Homopolar generator design have made the generators costeffective in a variety of processes, such as welding, that require highcurrent pulses. Analysis and design of homopolar motors and generators.
The diagram below depicts a simplified homopolar generator hpg. In the fall of 1831 when michael faraday performed the initial. Sometimes the name homopolar generator is reserved for this configuration. Rather than using a separate external circuit and a spinning disk, ive combined them into a twodisk arrangement. A press fixture holds workpieces as a homopolar generator sends a pulse of. When designing a homopolar motor the main operating. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The equivalent capacitance of a homopolar generator is determined with. This paper presents a novel highspeed alternating current ac homopolar motorgenerator design using stationary rebco excitation windings. The operation of a homopolar motor is a simple consequence of the lorentz force. Design of a homopolar generator power supply system for. A synchronous homopolar machine for highspeed applications perry tsao, matthew senesky, and seth sanders department of electrical engineering university of california, berkeley berkeley, ca 94720 power.
A permanent magnet motor which has no external energy input has been a. Homopolar generator efficiency investigation electron. Homopolar freeenergy generator test robert kincheloe professor of electrical engineering emeritus stanford university paper presented at the 1986 meeting of the society for scientific exploration san francisco june 21, 1986 revised february 1, 1987 homopolar freeenergy generator test robert kincheloe abstract known for over 150 years, the faraday homopolar. Dual counter rotating homopolar motor magnetic vortex motor part 4 duration. Chapter 2 homopolar dc generator hdg, operation, principle and applications. Homopolar generators some of the peculiarities of dynamo theory are well illustrated by the prototype example of selfexcited dynamo action, which is the homopolar disk dynamo. To continue this work, you can evaluate the performance of homopolar generator designs using the comsol multiphysics software. The setup for this device later called a homopolar.
The disk configuration is one type, but the drum type homopolar generator might have advantages. Learn more about shibboleth at brown brown university. Homopolar motor, homopolar generator university of new. Known for over 150 years, the faraday homopolar generator has been claimed to provide a basis for socalled free energy generation, in that under certain conditions the extraction of electrical output energy is not reflected as a corresponding mechanical load to the driving source. One half of the device in fig 1a is the disk, of a classic hpg, while the other half acts as the external circuit. In a homopolar motor the moving current carriers feel an induced force and move whereas in the side of the rotor feeling this force a torque is induced. Unconventional construction of the brushless homopolar generator probably reveals a predictive. Therefore, electric generator design software should combine all these types of analysis, and is often based on the finite element method.
Homopolar generators article about homopolar generators. Compact, lightweight, highefficiency motors and generators are sought for a multitude of applications. Machines free fulltext electromagnetic analysis and design. Homopolar generators are used mainly to obtain high currents 10 4 10 5 amperes at low voltages 110 volts. I find problems with the entry on the homopolar generator. The first homopolar generator was developed by michael faraday during his experiments in 1831. The result is that the galvanometer registers no current. Sodium potassium eutectic nak optimized using jmag r software. Since its invention by faraday in 1831, the homopolar generator has gone by many names. Study of homopolar dc generator the university of manchester. Homopolar generators unanswered questions and design details language. We have developed and tested a new superconducting homopolar motor and generator which has a specially designed magnetic field profile.
Since the electrical energy produced by the homopolar generator is a pure direct current dc such as with a battery, the power is constant and always optimum. Although no generator exists that meets the requirements of the ignitex experiment, the technologies needed for it have been demonstrated. This paper presents a novel highspeed alternating current ac homopolar motor generator design using stationary rebco excitation windings. Some of utcems early work included the design of machines that. The setup for this device later called a homopolar generator was simple, consisting of a copper disc that rotated in between the poles of a permanent magnet. Homopolar generator, afraday disk, nmachine, electrodynamics simulation 1 introduction the homopolar generator or aradafy disk is the oldest electric motor or generator and has been discovered by michael aradafy in 1831.
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