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I changed from RPM = {{{120 \times f}\over{p}}} TO RPM = {{{60 \times f}\over{p}}} I'm right? Minute has 60 seconds, ferquency is in Hz, so it is natural to multiplie with 60 not with 120, as is stated p is Number of pole pairs, not number of poles!
Variable frequency drives operate under the principle that the synchronous speed of an AC motor is determined by the frequency of the AC supply and the number of poles in the stator winding, according to the relation:
RPM = {{{60 \times f}\over{p}}}
where
RPM = Revolutions per minute
f = AC power frequency (hertz)
p = Number of pole pairs(an even number)
Synchronous motors operate at the synchronous speed determined by the above equation. The speed of an induction motor is slightly less than the synchronous speed.
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help)I agree: "I believe, the more usual way that the material is presented. I have several USA references including that state the poles in an AC motor as poles rather than pole pairs. Is "pole pairs" the more common usage elsewhere?" My personal expirience is that severeal european university are using pole pairs, but for USA references is more common use of poles. I'm living decision to You, but mayby difference should be stated somewhere in the page becouse of european students? —Preceding unsigned comment added by 89.188.39.77 ( talk) 12:53, 27 March 2008 (UTC)
My understanding is that there is a way to also use a controller like this to brake a motor by purposefully lagging the phases but it is not clear to me what the power-take-off circuit looks like in this case. Can anyone explain how regenerative breaking works in conjunction with this type of controller? —Preceding unsigned comment added by Laughingskeptic ( talk • contribs) 18:03, 24 November 2007 (UTC)
There is a novel (?) application of VFD in the Prius hybrid drive. The Regen energy of course goes into the traction battery. See also [1] Shannock9 ( talk) 01:49, 2 December 2009 (UTC)
There really should be something about regenerative braking in the main article. Cowie, can you do it? -- Treekids 20:18, 4 December 2007 (UTC)
I would consider the section on regenerative drives to be misleading. Regenerative drives are not common nor are they widely used in the United States. In 10 years I have only seen one and that was when it was being pulled out and replaced due to constant failure. Major manufacturers (such as Yaskawa) are only now beginning to offer regenerative drives but they have had problems. The picture in that section shows a drive that I have never heard of and could find no information on. Crane hoist applications in the U.S. (which is one application mentioned in that section) do not use regenerative drives 99.999% of the time - at least in my experienced estimation. Crane hoist use braking transistors and power resistors to burn off the regenerative energy. If regenerative drives are more common in other countries (which I cannot find nor have ever seen any evidence of) then that should be noted. Otherwise, regenerative drives are still a "maturing" technology. Slowchaos ( talk) 01:37, 7 June 2012 (UTC)
There really should be a few graphs/tables illustrating how the torque/power/power factor/efficiency/ are effected of when a VSD is used. —Preceding unsigned comment added by 119.11.27.116 ( talk) 13:59, 3 April 2009 (UTC)
Linear motors also use VFDs. Operating principles does not seem to cover these.
An anonymous editor just added the "Attention" template (well, sorta kinda) and the following text:
Until they added that text, I though the article was pretty fine, albeit a bit short. Now, I definitely agree that it needs "attention".
Does anyone feel strongly that this new text shouldn't be deleted (it's more relevant to Electric motor and the "attention" sorta-kinda template removed?
Atlant 17:17, 17 July 2005 (UTC)
exactly -vega007
I deleted the "attention" but left the "full speed listing" although I think the substance of it is covered under Electric motor. I would like to give this much more attention, but this is my first day. I am working on a more general article on adjustable speed drives. C J Cowie
Capacitor symbol polarity appears to be reversed in the PWM_VFD_Diagram.PNG image. The '+' symbol at the bus rail doesn't conform with the direction of the capacitor symbol (the 'flat' side should be towards '+'). Zootsuite 01:25, 14 May 2007 (UTC)
There are problems with the bolded addition to the following sentence: Various types of synchronous motors offer advantages in some situations, such as the use of hall sensors to control inverter frequency and pole switching to vary the frequency to rotational speed ratio, but induction motors are suitable for most purposes and are generally the most economical choice. The use of hall sensors in VFDs is generally not related to the type of motor used. Hall sensors are used in VFD circuits for current sensing and as one of several types of shaft speed and position sensor. Pole switching is a means of changing the operating speed of an AC motor, but it is generally not used in conjunction with variable frequency drives. -- C J Cowie 18:07, 12 March 2006 (UTC)
An article on servomotors, linking to this article and to "brushless DC" motors, would be useful, to fill out the area of motor control.
It's worth mentioning that "brushless DC" motors are really synchronous AC motors, and need a variable frequency drive. For historical reasons, small brushless servomotors are referred to as "brushless DC", and larger ones (1KW and up, typically) are referred to as AC motors. Brush-type DC motors, on the other hand, take a DC input.
There are newer variations on PWM control method. The standard method uses an image of the motor characteristic and pulses the frequency accordingly. Latest methods use Direct Torque Control and control the pulse width by reading the feedback from the motor. This enables individual phases to be pulsed more accurately and accounts for correction of imbalances prevalent in actual motor windings. Aroonl 03:48, 31 January 2007 (UTC)
I was wondering if we should include a section on line and load reactors and their use with VFDs. Is this common practice everywhere, or just for certain industries/regions/manufacturers? -- W0lfie 19:04, 15 March 2007 (UTC)
Also, I read somewhere that you should use shielded 1000V cable between the VFD and the motor. [2] for instance. Is that true? I haven't ever noticed any problems running regular unshielded 600V cable out to the motors. I couldn't find anything in the NEC at all about VFDs. -- W0lfie 19:04, 15 March 2007 (UTC)
This is an interesting page from an engineering standpoint, but perhaps someone could add a few sentences about what they're actually used for? —Preceding unsigned comment added by 204.11.6.125 ( talk) 19:09, 28 September 2007 (UTC)
For uses, see Adjustable-speed drive. C J Cowie 22:23, 28 September 2007 (UTC)
Uses! Its everywhere. Patricularly in industries to control speed of machines [Sandeep Poddar] —Preceding unsigned comment added by 59.89.48.60 ( talk) 02:38, 18 October 2007 (UTC)
Might I ask, can the vfd or similar be used for power generation? Is this used in hybrid cars? Wind energy generation? —Preceding unsigned comment added by 209.242.238.145 ( talk) 21:16, 15 November 2007 (UTC)
I've tried to post external links to three variable frequency drive articles that could really be a great research resource. For some strange reason, they will not post, and it's not from a lack of trying. I've posted them about 5 times. The links are as follows:
Article 1: The Benefits of Variable Frequency Drives - This article outlines the energy savings, the tighter process control, and the extension of equipment life through variable frequency drives. The website can be found at http://vfds.com/vfdbenefits.html
Article 2: How to Specify Variable Frequency Drives - This article describes the process one should follow to identify what type of variable frequency drive needed for a specific application. The article also offers some alternative views on how to size drives. The article is found at http://vfds.com/vfdspecify.html
Article 3: Harmonic Mitigation Specification for Variable Frequency Drives - This article explains the importance of harmonic mitigation control and the potential damage it can do to one's electrical system. The article can be found at http://vfds.com/harmonic-mitigation.html
Can anyone offer an explanation to why I am have issues with this?
Webmaster emc123 ( talk) 18:45, 14 February 2008 (UTC)
I had to guess that CSF refers to the switching frequency used in PWM systems. There should be a bit of wordage, or a link, explaining this term before using it in the article...... Jim, K7JEB ( talk) 01:18, 3 August 2008 (UTC)
I had exactly the same problem - CSF is not explained, and some would regard the word Carrier as redundant/confusing - it's just a switching frequency. I understand that some manufacturers use the term CSF, nevertheless to me it's either a carrier frequency or a switching frequency, but not a carrier switching frequency. The carrier itself is a square wave - the electronic components may be switched but the carrier is not.
A big part of the problem is that in this application of PWM there is conceptually a modulating waveform (the sinusoid we are attempting to feed to the motor) whereas in DC to DC PWM inverters the "modulating waveform" is a flat line! So if you come to this from (say) PC PSUs you are not used to having a modulating wave therefore you never learned to distinguish the carrier by that name.
Note the article on Class D amplifiers does not use the term Carrier at all.
Perhaps more importantly the diagram with the red bars appears to be incorrect. In order to synthesize a sinusoid the first and third bar of each triplet should be narrower than the second bar.
Shannock9 (
talk) 22:13, 29 May 2009 (UTC)
Well, I am quite happy to see how the Powerline harmonics section of this article has grown from my first stab at it. Thanks for all the hard work on improving the article.
A secondary purpose of the section is to make light of the issue that while VFDs can improve motor efficiency and may reduce metered power usage for a business, VFDs can also be detrimental to overall power quality and to other customers on the line, possibly many miles away.
I would bet that the compensation for harmonics isn't entirely loss-free by itself.... a power company choosing to install filtering at a substation is probably losing a certain percentage of power to run the compensators and "smooth out" the misshapen power sinewave.
DMahalko ( talk) 19:09, 3 November 2009 (UTC)
Did you mean "...make light of..." or "...shed light on..."? Shannock9 ( talk) 00:03, 2 December 2009 (UTC)
The "clade" diagram takes up a lot of space and is mostly not about VF drives. The accuracy of much of the text was doubtful. Things like "AC drives can be classified to be dominated in terms of rating total of historical and current installations by the following application areas" are impossible to parse. -- Wtshymanski ( talk) 14:42, 31 January 2012 (UTC) I don't agree and will go on to other things. Thanks and goodbye. — Preceding unsigned comment added by Cblambert ( talk • contribs) 01:41, 1 February 2012 (UTC) Cblambert ( talk) 17:46, 1 February 2012 (UTC)See also entry for Luddite, which is germane to issues raised by Wtshymanski's regressive arbitrary undos.
Table A: Topologies new content made collapsable
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For the record this is how VFD Types section read before recent 'wind back' VFD types can be expressed in terms of the range of variable speed drives shown in the following diagram [1] [2].
Table B: VFD types new content made collapsable
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AC drives can be classified to be dominated in terms of rating total of historical and current installations by the following application areas
[3] :
Synchronous machine applications
In a basic VVI drive, the DC output of the SCR-bridge rectifier is smoothed via DC link capacitor bus circuit to supply quasi-sinesoidal six-step voltage input to the inverter. In a basic VSI drive, the DC output of the diode-bridge rectifier stores energy via DC link capacitor bus circuit to supply stiff voltage input to the inverter. In a basic CSI drive, the DC output of the SCR-bridge rectifier stores energy via DC link inductor circuit to supply stiff current input to the inverter. A cycloconverter drive has no AC-to-DC converter and instead connects each output terminal to the appropriate input phase, making up the desired variable-frequency output waveforms by selective commutation from the fixed-frequency input waveforms. In a basic LCI drive, the DC output of the SCR-bridge converter stores energy via DC link inductor circuit to supply stiff quasi-sinesoidal six-step current input to a second SCR-bridge's inverter and an over-excited synchronous machine. Most packaged AC drives are VSI-PWM type using pulse width modulation to control the motor's frequency in scalar or open-loop Volts-per-Hertz (V/Hz) operating mode. Higher performance drives have been developed offering field-oriented control (FOC), closed-loop speed control with slip compensation, or direct torque control (DTC). PWM is not normally used with DTC [4]. VVI drives have largely been replaced by VSI-PWM drives [5]. CSI-PWM is also significant in high power AC drive applications [6]. VSI-PWM drives are often incorrectly referred to as PWM drives [7]. AC drives used in variable torque loads applications have historically been associated with general purpose 2-level PWM inverter topology in open loop V/Hz control. V/Hz control is also sometimes referred to as scalar control or variable voltage, variable frequency (VVVF) control. Higher performance load applications are increasingly been been used for AC drives with multi-level and cellular inverter topologies and closed loop and sensorless vector or DTC control. [3]. The expectation is that vector control will eventually universally replace scalar control for AC drives [8]. |
Cblambert ( talk) 07:26, 17 February 2012 (UTC)
I just want to comment that VFD's not only provide energy savings for high horsepower motors, it also assist in controlling non-steady steady state operating system.
For example: if there is a sudden load change on a pump motor (ie sudden pressure drop), the VFD can slow the motor down so the pump does not lose its prime (ie cavitation)
This is not an energy savings, per se, but I think it is worth mentioning in this talk page.
Cblambert ( talk) 17:46, 25 April 2012 (UTC) Deekayfry ( talk) 15:38, 25 April 2012 (UTC)
Table C: Energy Savings new content made collapsable
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For the record, recent 'Wind Back' to Energy Savings section undid the following contribution: It is estimated that:
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Cblambert ( talk) 07:32, 17 February 2012 (UTC)
Table C: Main Part new content made collapsable
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For the record, this is how 2nd paragraph of main Variable-frequency drive writeuplooked like before recent 'Wind Back' undo: Manufactured in a wide range of ratings and topologies, variable-frequency drives are used in a wide number of applications to control conveyors, divertors, palletizers, rotary kilns, fans, pumps, extruders, centrifuges, compressors, winders, chippers, cranes, punch presses, lifts, elevators, escalators, pulpers, refiners, shredders, chillers, thrusters, propellers, agitators, mixers, oxidizers, mills, equipment associated with wind generation, wind tunnel, locomotion, test stand and cogeneration installations, and so on. |
Cblambert ( talk) 07:40, 17 February 2012 (UTC)
I propose new section something along the lines of 'VFD Technology's Importance' based on pronouncements such as made at recent Workshopon Power Elctronics for Industrial Applications and Renewable Energy Conversion by Professor Bamil Bose in the keynote address, 'Energy Scenario and Impact of Power Electronics in the 21st Century'^, that "the role of power electronics in our society in future will be as important and versatile as computers and information technology today" . . .!
In regard to VFD technology's important, I also draw attention to the fact that a search today of IEEE Xplore ditigal database shows 9,241 records for the term 'Adjustable-speed drive'.
^ http://www.peia2011.com/downloads/Bose_fullpaper.pdf Cblambert ( talk) 04:17, 1 February 2012 (UTC) Cblambert ( talk) 04:18, 1 February 2012 (UTC) Cblambert ( talk) 04:40, 1 February 2012 (UTC) Cblambert ( talk) 05:11, 1 February 2012 (UTC) Cblambert ( talk) 05:34, 1 February 2012 (UTC) Cblambert ( talk) 05:35, 1 February 2012 (UTC)
I am primarily an observer here but wanted to create opportunity for discussion of the relevance of the content in Benefits section. Joja lozzo 18:03, 3 February 2012 (UTC)
The relevance goes something like this:
See section immediately above VFD Technology's Importance, especially about power electronics being as important in future as communications and computers are now.
Treatment in benefits could well be in sub-section of benefits Dsection.Maybe wording could be improved accordingly. Cblambert ( talk) 20:20, 3 February 2012 (UTC)
I am fairly new to making contributions to Wikipedia so I am puzzled by User Wtshymanski's wholesale ratcheting back of contributions in the past few days, including the one earlier today, which will not of course do. And I accordingly look forward to getting to the bottom of any further such arbitrary actions on User Wtshymanski' part. Best regards all Cblambert ( talk) 20:33, 3 February 2012 (UTC)
Cblambert ( talk) 22:04, 3 February 2012 (UTC)
With all due respect, whoever you are you, you are completely out line. Your comments need to be professional, which they currently aren't. CblambertI have corrected the 'rotating' typo. Many thanks. ( talk) 23:19, 3 February 2012 (UTC)
Cblambert ( talk) 17:12, 4 February 2012 (UTC)
You are entitled to your opinion. The new content is organized according to authoritative sources. New content may raise issues needing development but that is the price we all have to pay in dealing with difficult complex topics. I stand by my subtantial contributions as being offered in earnest. Cblambert ( talk) 18:57, 4 February 2012 (UTC)
Cblambert ( talk) 17:45, 13 March 2012 (UTC)
Those are some really ugly looking charts. The information pushes off the right edge of the screen unnecessarily because the heading branches don't nest subheadings underneath. Excessive abbreviation isn't helped by the table below it all.
Bullet lists would handle the data much more compactly, with greater readability, and allow for removal of all abbreviations, because long lines can be permitted to wrap around the page.
I don't claim to know what all these terms mean but it appears some types are either skipped or incomplete, which I've marked with ?. If there's no information available then the branches should likely be removed as they add nothing to the article.
DMahalko ( talk) 17:51, 13 March 2012 (UTC)
New section started to keep the disussion at the professional level. Re clade diagrams:
Cblambert, I'll defer to your opinion on what the legend should and shouldn't contain. But I'm not sure how useful the VFD type tables are as presented: they're too terse to be intelligible to non-experts, yet an expert will already know the information. Somehow, it'd be nice to capture the same information in a format that provides more opportunity for explanation, such as narrative text. Motor control terms of art which have unexpected meanings (like 6KV being "medium voltage"), really deserve an introductory explanation. Olawlor ( talk) 08:19, 14 March 2012 (UTC)
Actually, now that the "drives by topologies" diagram now contains manufacturer info, I find it a lot more useful. Cblambert, when the content is basically done, let me know and I can try to reformat it as a more readable table. I'm also trying to figure out the commonalities of all the topologies enough to draw a useful generic system diagram: but there are a lot of options between {diode or thyristor rectification} x {inductor or capacitor energy storage} x {transistor or thyristor inverter} x {multi levels}. Plus I'm realizing quite how out of my depth I am in this stuff... (Off topic: I ordered my first VFD today! A little 1.5kW 240V unit for my lathe.) Olawlor ( talk) 11:00, 17 March 2012 (UTC)
Cblambert ( talk) 16:50, 17 March 2012 (UTC)
Article's Ref. 13^ defines (on slide 3) AC drive topology as a 'A map-like diagram showing the elements of an AC drive and the relationship between them.', which until this week used to be referenced with Table 2. This definition cries out for the VFD article to come up with:
^ TMEIC link as http://tmeic-ge.com/upload/library_docs/english/MV_AC_Drive_Topology_Analysis_1143643595.pdf
Cblambert ( talk) 05:29, 15 March 2012 (UTC)
I have always felt that article's 'Benefits' section needed shoring up in terms of:
Cblambert, would you care to discuss your wholesale revert of my work on 16:26, 14 March 2012? The existing system diagram doesn't clearly illustrate (1) multipole inputs and outputs nor (2) actual variable-frequency output (the output signal just looks like a quantized sin wave). For discussion purposes, I've attached my figure here. Any other editors care to chime in as to whether this figure would improve the article? My goal is to briefly convey what on earth a VFD does before going into the gory details. Olawlor ( talk) 08:32, 15 March 2012 (UTC)
(Comment edited as follows as it occurs to me that original text may contravene Professor Bose's copyright.)
This AC drive article would benefit from having a detailed history section along the lines of of the excellent history section off provided in the Transformer article. Professor Bose's 2006 book provides in Fig 1.16 (to use as broad outline for discussion purposes) the following four generations of solid-state power electronics:
Professor Bose uses an impressive number of Wikipedia entries to describe these four generation including the following entries: Diode, Thyristor, Triac, Power BJT, power MOSFET, GTO, Microprocessor, ASIC, PIC, advanced control, IGBT, DSPs, advanced control, IGCT, cool MOS, sensorless control, AI, fuzzy logic, and neural networks (Only a handful of other terms are not Wikipedia entries.)
Anyone interested in working on such VFD history section? Cblambert ( talk) 21:59, 15 March 2012 (UTC)
This Wikipedia pillar is sorely lacking a the part of some editors in this an other similar associated articles. Cblambert ( talk) 20:13, 17 March 2012 (UTC)
It would be nice to come up with a 'Green energy' section in the form of possible a HEV Hybrid Block Diagram at link http://twinkle_toes_engineering.home.comcast.net/~twinkle_toes_engineering/hybrid_car.htm#Toyota/Ford/Lexus hybrid block diagram (2nd link in link from the top). Cblambert ( talk) 02:52, 21 March 2012 (UTC)
Re: http://www.emcsolutions.com/article_vfd_benefits.html
Re: "Guide to Variable Speed Drives - Technical Guide No. 4". Technical Guides (ABB).
Re: "DC or AC Drives? A guide for users of variable-speed drives (VSDs)". ABB
Re: http://www.optimacs.com/reports/Understanding%20the%20control%20system.pdf One of the citation footnotes which I did not clean up. Citation could be done away with.
^ "AC and DC Variable Speed Drives Application Considerations". Rockwell Automation.
Re: "A Guide to Standard Medium Voltage Variable Speed Drives, Part 2". ABB
Re: Paes, Richard (June 2011). "An Overview of Medium Voltage AC Adjustable Speed Drives and IEEE Std. 1566 – Standard for Performance of Adjustable Speed AC Drives Rated 375 kW* and Larger".
Re: ACS800 Catalog - Single Drives 0.55 to 5600 kW. ABB.
Re: Lockley, Bill; Wood, Barry, Paes, Richard, DeWinter, Frank (Jan.-Feb. 2008). "Standard 1566 for (Un)Familiar Hands".
Re: Klug, Dieter-Rolf; Klaassen, Norbert (2005). "High Power Medium Voltage Drives - Innovations, Portfolio, Trends".
Re: DuraBilt5i MV Topologies Comparisons & Features-Benefits". TMEIC.
^ "Guide to Harmonics with AC Drives - Technical Guide No. 6". Technical Guides (ABB).
Re: Skibinski, Gary; Breit, Stephen (2004). "Line and Load Friendly Drive Solutions for Long Length Cable Applications in Electrical Submersible Pump Applications".
Re: "Application Report Long Drive/Motor Leads". Yaskawa Electric America, Inc.
Re: "A-B Reliance GV3000 FAQs Who Cares About Carrier Frequency?".
Re: "Bearing Currents in Modern AC Drive Systems - Technical Guide No. 5". Technical Guides (ABB).
Re: "EMC Compliant Installation and Configuration for a Power Drive System - Technical Guide No. 3". Technical Guides (ABB).
Cblambert ( talk) 21:10, 12 April 2012 (UTC)
Cblambert ( talk) 22:13, 12 April 2012 (UTC)
Cblambert ( talk) 22:58, 12 April 2012 (UTC)
What Bose has to say about power electtronics information is interesting:
Cblambert ( talk) 21:20, 17 April 2012 (UTC)
Re: Basics of AC Drives
Re: Motoring Ahead
Cblambert ( talk) 15:15, 18 April 2012 (UTC)
In case deletion of subject derivation should need to be restored, I have revised compared to last article version to read as follows:
"In principle, the inverter current and voltage outputs to the motor are respectively directly proportional to the motor torque and speed, whereas on the constant-voltage AC input to the VFD, the current is directly proportional to the power drawn by the motor. That is, neglecting VFD system losses and assuming unity power factor at AC input to VFD, U*I ~ T*N, where T = motor shaft torque, N = motor speed.
Neglecting losses assuming unity VFD input power factor, we have:
Given that 1.732*Ui is a constant, Ii = Tm*Nm/1.732*Ui and Ii ~ Tm*Nm; that is, AC current input to VFD is directly proportional to motor power."
Derivation has not enough to do with VFD operation. Unity power factor assumption for VFD input is approximately true for diode rectifier drives but not active switching device VFD front ends. As stated, derivation is not really relevant.
Cblambert ( talk) 18:21, 15 April 2012 (UTC)
As a matter of interest, number of watchers of VFD article (~65) is about 4 times less than transformer and motor articles (each ~245). I don't know exactly what you make of this but others may have insights worth sharing. Cblambert ( talk) 20:22, 18 April 2012 (UTC)
added information on four quadrant control Shrikanthv ( talk) 08:07, 19 April 2012 (UTC)
Electric motor speed-torque chart is incorrect:
The image copies the same mistake as 'Basics of AC Drives' 4-quadrant speed-torque chart and is likely violation of copyright. Cblambert ( talk) 20:18, 19 April 2012 (UTC)
Image should be labelled to match this text:
Cblambert ( talk) 02:48, 20 April 2012 (UTC)
Some of the information regarding regeneration and braking were got from the links below , why are they being considered commercial links and being deleted ? please discuss
1) http://kimo.de/index.php?file=produkte/fu/u2/PB-TU2-06-08-22.html&menu=6&nav=1&lang=EN 2) http://kimo.de/index.php?file=anwend/kostenfu/PRO-Kosten-FU.html&lang=EN
It is true company related articles does contain wordings like , this is best suitable ... but i do believe information outwieghs the possible 'loss' Shrikanthv ( talk) 08:09, 20 April 2012 (UTC)
The sourcing in this article needs some work. In particular there is one [citation needed] tag and some paragraphs have no citations at all. The citation style is also a bit confusing (why are there references linked on their own line below the headings. The multiple citations (although not strictly a criteria) could be reduced. A large number of citations following a sentence tend to suggest the presence of original research and make reading the prose difficult. AIRcorn (talk) 04:13, 17 May 2012 (UTC)
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Reviewing |
Reviewer: Pyrotec ( talk · contribs) 14:03, 17 May 2012 (UTC)
I've had a quick read of the article and now I'm going to work my way through the article section by section, but leaving the WP:Lead until the end of the article.
On the basis of this quick reading, the article appears to have sufficient material to be considered for GA-status; but further improvements will be needed to obtain GA status this time round. For example: the current Lead is non-compliant with the requirements of WP:Lead since it is only provides an introduction for the article and makes no effort to summarise the main points. (I shall be covering this later in detail). There are also whole paragraphs, such as the first paragraph of Energy savings subsection of Benefits, that are unreferenced. The grammar/prose in some sentences is poor.
The requirements for GA can be found in WP:WIAGA, which is what I will be assessing the article against.
... to be continued. Pyrotec ( talk) 17:27, 20 May 2012 (UTC)
... to be continued. Pyrotec ( talk) 12:49, 19 May 2012 (UTC)
Drive type | DC | VFD | VFD | VFD |
---|---|---|---|---|
Criteria | Brush Type DC | AC V/Hz Control | AC Open-Loop Vector | AC Closed-Loop Flux Vector |
Typical speed regulation (%) | 0.01 | 1 | 0.5 | 0.01 |
Typical speed range at constant torque | 0-100 | 10-100 | 3-100 | 0-100 |
Min. speed at 100% torque (% of base) | Standstill | 8% | 2% | Standstill |
Multiple-motor operation recommended | No | Yes | No | No |
Fault protection (Fused only or inherent to drive) | Fused only | Inherent | Inherent | Inherent |
Maintenance | (Brushes) | Low | Low | Low |
Feedback device | Tachometer or encoder | N/A | N/A | Encoder |
...stopping for now. To be continued. Pyrotec ( talk) 19:01, 19 May 2012 (UTC)
...stopping for now. To be continued. Pyrotec ( talk) 21:31, 19 May 2012 (UTC)
...stopping for now. Pyrotec ( talk) 09:33, 22 May 2012 (UTC)
Pyrotec ( talk) 12:24, 23 May 2012 (UTC)
GA review – see WP:WIAGA for criteria
I'm awarding this article GA status. Congratulations on producing what is now fine article. Pyrotec ( talk) 11:37, 25 May 2012 (UTC)
I'm awarding this article GA status. Congratulations on producing, what is now, a fine article. Pyrotec ( talk) 11:37, 25 May 2012 (UTC)
I am going to rewrite lead section matching with wiki guidlines Shrikanthv ( talk) 11:49, 24 May 2012 (UTC)
Please check revert back on new edits on Lead section , hope it is now matching wiki guidlines
Shrikanthv (
talk) 11:05, 25 May 2012 (UTC)
Can we talk why the lead is being reverted back after getting GA ? , while the current (which was previous one ) did not match with GA guidlines Shrikanthv ( talk) 15:31, 25 May 2012 (UTC)
Good article - obviously lots of thought and time spent. However the "stiffness" query was never answered ( Thévenin's theorem article has no mention). I concede that to anyone with any exposure to AC circuit theory it's an obvious metaphor, but we cannot assume that background. So I propose the following edit to the first appearances...stiff voltage [low impedance]...stiff current [high impedance]. Note the links to the Impedance article. Shannock9 ( talk) 09:55, 26 August 2013 (UTC)
I have a concern that I'm not knowledgeable enough to resolve.
Probably quite unintentionally by its authors, the article tone comes over (on the surface) to be generally skewed towards promoting these devices, or making them sound desirable or a significant opportunity, rather than merely factual info about that topic. For example -
Perhaps these aspects of the topic can be better covered under a section "VFD market and adoption" - they are relevant to the topic, but placed as they are, it comes over as pushing this angle rather than providing encyclopedic coverage. FT2 ( Talk | email) 07:20, 9 October 2015 (UTC)
The lead section of this article is extremely difficult to fathom:
VFDs are used in applications ranging from small appliances to the largest of mine mill drives and compressors. However, around 25% of the world's electrical energy is consumed by electric motors in industrial applications, which are especially conducive for energy savings using VFDs in centrifugal load service,[5] and VFDs' global market penetration for all applications is still relatively small. That lack of penetration highlights significant energy efficiency improvement opportunities for retrofitted and new VFD installations.
I see no reason at all why the word "However" appears there, the term "centrifugal load service" seems to be very obscure, and the end of the paragraph seems disconnected from the beginning of it. NotYourFathersOldsmobile ( talk) 02:11, 18 March 2016 (UTC)
VFD as in the volunteer fire department aaaaa jacques is dead — Preceding unsigned comment added by Plutonical ( talk • contribs) 21:49, 7 April 2018 (UTC)
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I changed from RPM = {{{120 \times f}\over{p}}} TO RPM = {{{60 \times f}\over{p}}} I'm right? Minute has 60 seconds, ferquency is in Hz, so it is natural to multiplie with 60 not with 120, as is stated p is Number of pole pairs, not number of poles!
Variable frequency drives operate under the principle that the synchronous speed of an AC motor is determined by the frequency of the AC supply and the number of poles in the stator winding, according to the relation:
RPM = {{{60 \times f}\over{p}}}
where
RPM = Revolutions per minute
f = AC power frequency (hertz)
p = Number of pole pairs(an even number)
Synchronous motors operate at the synchronous speed determined by the above equation. The speed of an induction motor is slightly less than the synchronous speed.
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help)I agree: "I believe, the more usual way that the material is presented. I have several USA references including that state the poles in an AC motor as poles rather than pole pairs. Is "pole pairs" the more common usage elsewhere?" My personal expirience is that severeal european university are using pole pairs, but for USA references is more common use of poles. I'm living decision to You, but mayby difference should be stated somewhere in the page becouse of european students? —Preceding unsigned comment added by 89.188.39.77 ( talk) 12:53, 27 March 2008 (UTC)
My understanding is that there is a way to also use a controller like this to brake a motor by purposefully lagging the phases but it is not clear to me what the power-take-off circuit looks like in this case. Can anyone explain how regenerative breaking works in conjunction with this type of controller? —Preceding unsigned comment added by Laughingskeptic ( talk • contribs) 18:03, 24 November 2007 (UTC)
There is a novel (?) application of VFD in the Prius hybrid drive. The Regen energy of course goes into the traction battery. See also [1] Shannock9 ( talk) 01:49, 2 December 2009 (UTC)
There really should be something about regenerative braking in the main article. Cowie, can you do it? -- Treekids 20:18, 4 December 2007 (UTC)
I would consider the section on regenerative drives to be misleading. Regenerative drives are not common nor are they widely used in the United States. In 10 years I have only seen one and that was when it was being pulled out and replaced due to constant failure. Major manufacturers (such as Yaskawa) are only now beginning to offer regenerative drives but they have had problems. The picture in that section shows a drive that I have never heard of and could find no information on. Crane hoist applications in the U.S. (which is one application mentioned in that section) do not use regenerative drives 99.999% of the time - at least in my experienced estimation. Crane hoist use braking transistors and power resistors to burn off the regenerative energy. If regenerative drives are more common in other countries (which I cannot find nor have ever seen any evidence of) then that should be noted. Otherwise, regenerative drives are still a "maturing" technology. Slowchaos ( talk) 01:37, 7 June 2012 (UTC)
There really should be a few graphs/tables illustrating how the torque/power/power factor/efficiency/ are effected of when a VSD is used. —Preceding unsigned comment added by 119.11.27.116 ( talk) 13:59, 3 April 2009 (UTC)
Linear motors also use VFDs. Operating principles does not seem to cover these.
An anonymous editor just added the "Attention" template (well, sorta kinda) and the following text:
Until they added that text, I though the article was pretty fine, albeit a bit short. Now, I definitely agree that it needs "attention".
Does anyone feel strongly that this new text shouldn't be deleted (it's more relevant to Electric motor and the "attention" sorta-kinda template removed?
Atlant 17:17, 17 July 2005 (UTC)
exactly -vega007
I deleted the "attention" but left the "full speed listing" although I think the substance of it is covered under Electric motor. I would like to give this much more attention, but this is my first day. I am working on a more general article on adjustable speed drives. C J Cowie
Capacitor symbol polarity appears to be reversed in the PWM_VFD_Diagram.PNG image. The '+' symbol at the bus rail doesn't conform with the direction of the capacitor symbol (the 'flat' side should be towards '+'). Zootsuite 01:25, 14 May 2007 (UTC)
There are problems with the bolded addition to the following sentence: Various types of synchronous motors offer advantages in some situations, such as the use of hall sensors to control inverter frequency and pole switching to vary the frequency to rotational speed ratio, but induction motors are suitable for most purposes and are generally the most economical choice. The use of hall sensors in VFDs is generally not related to the type of motor used. Hall sensors are used in VFD circuits for current sensing and as one of several types of shaft speed and position sensor. Pole switching is a means of changing the operating speed of an AC motor, but it is generally not used in conjunction with variable frequency drives. -- C J Cowie 18:07, 12 March 2006 (UTC)
An article on servomotors, linking to this article and to "brushless DC" motors, would be useful, to fill out the area of motor control.
It's worth mentioning that "brushless DC" motors are really synchronous AC motors, and need a variable frequency drive. For historical reasons, small brushless servomotors are referred to as "brushless DC", and larger ones (1KW and up, typically) are referred to as AC motors. Brush-type DC motors, on the other hand, take a DC input.
There are newer variations on PWM control method. The standard method uses an image of the motor characteristic and pulses the frequency accordingly. Latest methods use Direct Torque Control and control the pulse width by reading the feedback from the motor. This enables individual phases to be pulsed more accurately and accounts for correction of imbalances prevalent in actual motor windings. Aroonl 03:48, 31 January 2007 (UTC)
I was wondering if we should include a section on line and load reactors and their use with VFDs. Is this common practice everywhere, or just for certain industries/regions/manufacturers? -- W0lfie 19:04, 15 March 2007 (UTC)
Also, I read somewhere that you should use shielded 1000V cable between the VFD and the motor. [2] for instance. Is that true? I haven't ever noticed any problems running regular unshielded 600V cable out to the motors. I couldn't find anything in the NEC at all about VFDs. -- W0lfie 19:04, 15 March 2007 (UTC)
This is an interesting page from an engineering standpoint, but perhaps someone could add a few sentences about what they're actually used for? —Preceding unsigned comment added by 204.11.6.125 ( talk) 19:09, 28 September 2007 (UTC)
For uses, see Adjustable-speed drive. C J Cowie 22:23, 28 September 2007 (UTC)
Uses! Its everywhere. Patricularly in industries to control speed of machines [Sandeep Poddar] —Preceding unsigned comment added by 59.89.48.60 ( talk) 02:38, 18 October 2007 (UTC)
Might I ask, can the vfd or similar be used for power generation? Is this used in hybrid cars? Wind energy generation? —Preceding unsigned comment added by 209.242.238.145 ( talk) 21:16, 15 November 2007 (UTC)
I've tried to post external links to three variable frequency drive articles that could really be a great research resource. For some strange reason, they will not post, and it's not from a lack of trying. I've posted them about 5 times. The links are as follows:
Article 1: The Benefits of Variable Frequency Drives - This article outlines the energy savings, the tighter process control, and the extension of equipment life through variable frequency drives. The website can be found at http://vfds.com/vfdbenefits.html
Article 2: How to Specify Variable Frequency Drives - This article describes the process one should follow to identify what type of variable frequency drive needed for a specific application. The article also offers some alternative views on how to size drives. The article is found at http://vfds.com/vfdspecify.html
Article 3: Harmonic Mitigation Specification for Variable Frequency Drives - This article explains the importance of harmonic mitigation control and the potential damage it can do to one's electrical system. The article can be found at http://vfds.com/harmonic-mitigation.html
Can anyone offer an explanation to why I am have issues with this?
Webmaster emc123 ( talk) 18:45, 14 February 2008 (UTC)
I had to guess that CSF refers to the switching frequency used in PWM systems. There should be a bit of wordage, or a link, explaining this term before using it in the article...... Jim, K7JEB ( talk) 01:18, 3 August 2008 (UTC)
I had exactly the same problem - CSF is not explained, and some would regard the word Carrier as redundant/confusing - it's just a switching frequency. I understand that some manufacturers use the term CSF, nevertheless to me it's either a carrier frequency or a switching frequency, but not a carrier switching frequency. The carrier itself is a square wave - the electronic components may be switched but the carrier is not.
A big part of the problem is that in this application of PWM there is conceptually a modulating waveform (the sinusoid we are attempting to feed to the motor) whereas in DC to DC PWM inverters the "modulating waveform" is a flat line! So if you come to this from (say) PC PSUs you are not used to having a modulating wave therefore you never learned to distinguish the carrier by that name.
Note the article on Class D amplifiers does not use the term Carrier at all.
Perhaps more importantly the diagram with the red bars appears to be incorrect. In order to synthesize a sinusoid the first and third bar of each triplet should be narrower than the second bar.
Shannock9 (
talk) 22:13, 29 May 2009 (UTC)
Well, I am quite happy to see how the Powerline harmonics section of this article has grown from my first stab at it. Thanks for all the hard work on improving the article.
A secondary purpose of the section is to make light of the issue that while VFDs can improve motor efficiency and may reduce metered power usage for a business, VFDs can also be detrimental to overall power quality and to other customers on the line, possibly many miles away.
I would bet that the compensation for harmonics isn't entirely loss-free by itself.... a power company choosing to install filtering at a substation is probably losing a certain percentage of power to run the compensators and "smooth out" the misshapen power sinewave.
DMahalko ( talk) 19:09, 3 November 2009 (UTC)
Did you mean "...make light of..." or "...shed light on..."? Shannock9 ( talk) 00:03, 2 December 2009 (UTC)
The "clade" diagram takes up a lot of space and is mostly not about VF drives. The accuracy of much of the text was doubtful. Things like "AC drives can be classified to be dominated in terms of rating total of historical and current installations by the following application areas" are impossible to parse. -- Wtshymanski ( talk) 14:42, 31 January 2012 (UTC) I don't agree and will go on to other things. Thanks and goodbye. — Preceding unsigned comment added by Cblambert ( talk • contribs) 01:41, 1 February 2012 (UTC) Cblambert ( talk) 17:46, 1 February 2012 (UTC)See also entry for Luddite, which is germane to issues raised by Wtshymanski's regressive arbitrary undos.
Table A: Topologies new content made collapsable
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For the record this is how VFD Types section read before recent 'wind back' VFD types can be expressed in terms of the range of variable speed drives shown in the following diagram [1] [2].
Table B: VFD types new content made collapsable
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AC drives can be classified to be dominated in terms of rating total of historical and current installations by the following application areas
[3] :
Synchronous machine applications
In a basic VVI drive, the DC output of the SCR-bridge rectifier is smoothed via DC link capacitor bus circuit to supply quasi-sinesoidal six-step voltage input to the inverter. In a basic VSI drive, the DC output of the diode-bridge rectifier stores energy via DC link capacitor bus circuit to supply stiff voltage input to the inverter. In a basic CSI drive, the DC output of the SCR-bridge rectifier stores energy via DC link inductor circuit to supply stiff current input to the inverter. A cycloconverter drive has no AC-to-DC converter and instead connects each output terminal to the appropriate input phase, making up the desired variable-frequency output waveforms by selective commutation from the fixed-frequency input waveforms. In a basic LCI drive, the DC output of the SCR-bridge converter stores energy via DC link inductor circuit to supply stiff quasi-sinesoidal six-step current input to a second SCR-bridge's inverter and an over-excited synchronous machine. Most packaged AC drives are VSI-PWM type using pulse width modulation to control the motor's frequency in scalar or open-loop Volts-per-Hertz (V/Hz) operating mode. Higher performance drives have been developed offering field-oriented control (FOC), closed-loop speed control with slip compensation, or direct torque control (DTC). PWM is not normally used with DTC [4]. VVI drives have largely been replaced by VSI-PWM drives [5]. CSI-PWM is also significant in high power AC drive applications [6]. VSI-PWM drives are often incorrectly referred to as PWM drives [7]. AC drives used in variable torque loads applications have historically been associated with general purpose 2-level PWM inverter topology in open loop V/Hz control. V/Hz control is also sometimes referred to as scalar control or variable voltage, variable frequency (VVVF) control. Higher performance load applications are increasingly been been used for AC drives with multi-level and cellular inverter topologies and closed loop and sensorless vector or DTC control. [3]. The expectation is that vector control will eventually universally replace scalar control for AC drives [8]. |
Cblambert ( talk) 07:26, 17 February 2012 (UTC)
I just want to comment that VFD's not only provide energy savings for high horsepower motors, it also assist in controlling non-steady steady state operating system.
For example: if there is a sudden load change on a pump motor (ie sudden pressure drop), the VFD can slow the motor down so the pump does not lose its prime (ie cavitation)
This is not an energy savings, per se, but I think it is worth mentioning in this talk page.
Cblambert ( talk) 17:46, 25 April 2012 (UTC) Deekayfry ( talk) 15:38, 25 April 2012 (UTC)
Table C: Energy Savings new content made collapsable
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For the record, recent 'Wind Back' to Energy Savings section undid the following contribution: It is estimated that:
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Cblambert ( talk) 07:32, 17 February 2012 (UTC)
Table C: Main Part new content made collapsable
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For the record, this is how 2nd paragraph of main Variable-frequency drive writeuplooked like before recent 'Wind Back' undo: Manufactured in a wide range of ratings and topologies, variable-frequency drives are used in a wide number of applications to control conveyors, divertors, palletizers, rotary kilns, fans, pumps, extruders, centrifuges, compressors, winders, chippers, cranes, punch presses, lifts, elevators, escalators, pulpers, refiners, shredders, chillers, thrusters, propellers, agitators, mixers, oxidizers, mills, equipment associated with wind generation, wind tunnel, locomotion, test stand and cogeneration installations, and so on. |
Cblambert ( talk) 07:40, 17 February 2012 (UTC)
I propose new section something along the lines of 'VFD Technology's Importance' based on pronouncements such as made at recent Workshopon Power Elctronics for Industrial Applications and Renewable Energy Conversion by Professor Bamil Bose in the keynote address, 'Energy Scenario and Impact of Power Electronics in the 21st Century'^, that "the role of power electronics in our society in future will be as important and versatile as computers and information technology today" . . .!
In regard to VFD technology's important, I also draw attention to the fact that a search today of IEEE Xplore ditigal database shows 9,241 records for the term 'Adjustable-speed drive'.
^ http://www.peia2011.com/downloads/Bose_fullpaper.pdf Cblambert ( talk) 04:17, 1 February 2012 (UTC) Cblambert ( talk) 04:18, 1 February 2012 (UTC) Cblambert ( talk) 04:40, 1 February 2012 (UTC) Cblambert ( talk) 05:11, 1 February 2012 (UTC) Cblambert ( talk) 05:34, 1 February 2012 (UTC) Cblambert ( talk) 05:35, 1 February 2012 (UTC)
I am primarily an observer here but wanted to create opportunity for discussion of the relevance of the content in Benefits section. Joja lozzo 18:03, 3 February 2012 (UTC)
The relevance goes something like this:
See section immediately above VFD Technology's Importance, especially about power electronics being as important in future as communications and computers are now.
Treatment in benefits could well be in sub-section of benefits Dsection.Maybe wording could be improved accordingly. Cblambert ( talk) 20:20, 3 February 2012 (UTC)
I am fairly new to making contributions to Wikipedia so I am puzzled by User Wtshymanski's wholesale ratcheting back of contributions in the past few days, including the one earlier today, which will not of course do. And I accordingly look forward to getting to the bottom of any further such arbitrary actions on User Wtshymanski' part. Best regards all Cblambert ( talk) 20:33, 3 February 2012 (UTC)
Cblambert ( talk) 22:04, 3 February 2012 (UTC)
With all due respect, whoever you are you, you are completely out line. Your comments need to be professional, which they currently aren't. CblambertI have corrected the 'rotating' typo. Many thanks. ( talk) 23:19, 3 February 2012 (UTC)
Cblambert ( talk) 17:12, 4 February 2012 (UTC)
You are entitled to your opinion. The new content is organized according to authoritative sources. New content may raise issues needing development but that is the price we all have to pay in dealing with difficult complex topics. I stand by my subtantial contributions as being offered in earnest. Cblambert ( talk) 18:57, 4 February 2012 (UTC)
Cblambert ( talk) 17:45, 13 March 2012 (UTC)
Those are some really ugly looking charts. The information pushes off the right edge of the screen unnecessarily because the heading branches don't nest subheadings underneath. Excessive abbreviation isn't helped by the table below it all.
Bullet lists would handle the data much more compactly, with greater readability, and allow for removal of all abbreviations, because long lines can be permitted to wrap around the page.
I don't claim to know what all these terms mean but it appears some types are either skipped or incomplete, which I've marked with ?. If there's no information available then the branches should likely be removed as they add nothing to the article.
DMahalko ( talk) 17:51, 13 March 2012 (UTC)
New section started to keep the disussion at the professional level. Re clade diagrams:
Cblambert, I'll defer to your opinion on what the legend should and shouldn't contain. But I'm not sure how useful the VFD type tables are as presented: they're too terse to be intelligible to non-experts, yet an expert will already know the information. Somehow, it'd be nice to capture the same information in a format that provides more opportunity for explanation, such as narrative text. Motor control terms of art which have unexpected meanings (like 6KV being "medium voltage"), really deserve an introductory explanation. Olawlor ( talk) 08:19, 14 March 2012 (UTC)
Actually, now that the "drives by topologies" diagram now contains manufacturer info, I find it a lot more useful. Cblambert, when the content is basically done, let me know and I can try to reformat it as a more readable table. I'm also trying to figure out the commonalities of all the topologies enough to draw a useful generic system diagram: but there are a lot of options between {diode or thyristor rectification} x {inductor or capacitor energy storage} x {transistor or thyristor inverter} x {multi levels}. Plus I'm realizing quite how out of my depth I am in this stuff... (Off topic: I ordered my first VFD today! A little 1.5kW 240V unit for my lathe.) Olawlor ( talk) 11:00, 17 March 2012 (UTC)
Cblambert ( talk) 16:50, 17 March 2012 (UTC)
Article's Ref. 13^ defines (on slide 3) AC drive topology as a 'A map-like diagram showing the elements of an AC drive and the relationship between them.', which until this week used to be referenced with Table 2. This definition cries out for the VFD article to come up with:
^ TMEIC link as http://tmeic-ge.com/upload/library_docs/english/MV_AC_Drive_Topology_Analysis_1143643595.pdf
Cblambert ( talk) 05:29, 15 March 2012 (UTC)
I have always felt that article's 'Benefits' section needed shoring up in terms of:
Cblambert, would you care to discuss your wholesale revert of my work on 16:26, 14 March 2012? The existing system diagram doesn't clearly illustrate (1) multipole inputs and outputs nor (2) actual variable-frequency output (the output signal just looks like a quantized sin wave). For discussion purposes, I've attached my figure here. Any other editors care to chime in as to whether this figure would improve the article? My goal is to briefly convey what on earth a VFD does before going into the gory details. Olawlor ( talk) 08:32, 15 March 2012 (UTC)
(Comment edited as follows as it occurs to me that original text may contravene Professor Bose's copyright.)
This AC drive article would benefit from having a detailed history section along the lines of of the excellent history section off provided in the Transformer article. Professor Bose's 2006 book provides in Fig 1.16 (to use as broad outline for discussion purposes) the following four generations of solid-state power electronics:
Professor Bose uses an impressive number of Wikipedia entries to describe these four generation including the following entries: Diode, Thyristor, Triac, Power BJT, power MOSFET, GTO, Microprocessor, ASIC, PIC, advanced control, IGBT, DSPs, advanced control, IGCT, cool MOS, sensorless control, AI, fuzzy logic, and neural networks (Only a handful of other terms are not Wikipedia entries.)
Anyone interested in working on such VFD history section? Cblambert ( talk) 21:59, 15 March 2012 (UTC)
This Wikipedia pillar is sorely lacking a the part of some editors in this an other similar associated articles. Cblambert ( talk) 20:13, 17 March 2012 (UTC)
It would be nice to come up with a 'Green energy' section in the form of possible a HEV Hybrid Block Diagram at link http://twinkle_toes_engineering.home.comcast.net/~twinkle_toes_engineering/hybrid_car.htm#Toyota/Ford/Lexus hybrid block diagram (2nd link in link from the top). Cblambert ( talk) 02:52, 21 March 2012 (UTC)
Re: http://www.emcsolutions.com/article_vfd_benefits.html
Re: "Guide to Variable Speed Drives - Technical Guide No. 4". Technical Guides (ABB).
Re: "DC or AC Drives? A guide for users of variable-speed drives (VSDs)". ABB
Re: http://www.optimacs.com/reports/Understanding%20the%20control%20system.pdf One of the citation footnotes which I did not clean up. Citation could be done away with.
^ "AC and DC Variable Speed Drives Application Considerations". Rockwell Automation.
Re: "A Guide to Standard Medium Voltage Variable Speed Drives, Part 2". ABB
Re: Paes, Richard (June 2011). "An Overview of Medium Voltage AC Adjustable Speed Drives and IEEE Std. 1566 – Standard for Performance of Adjustable Speed AC Drives Rated 375 kW* and Larger".
Re: ACS800 Catalog - Single Drives 0.55 to 5600 kW. ABB.
Re: Lockley, Bill; Wood, Barry, Paes, Richard, DeWinter, Frank (Jan.-Feb. 2008). "Standard 1566 for (Un)Familiar Hands".
Re: Klug, Dieter-Rolf; Klaassen, Norbert (2005). "High Power Medium Voltage Drives - Innovations, Portfolio, Trends".
Re: DuraBilt5i MV Topologies Comparisons & Features-Benefits". TMEIC.
^ "Guide to Harmonics with AC Drives - Technical Guide No. 6". Technical Guides (ABB).
Re: Skibinski, Gary; Breit, Stephen (2004). "Line and Load Friendly Drive Solutions for Long Length Cable Applications in Electrical Submersible Pump Applications".
Re: "Application Report Long Drive/Motor Leads". Yaskawa Electric America, Inc.
Re: "A-B Reliance GV3000 FAQs Who Cares About Carrier Frequency?".
Re: "Bearing Currents in Modern AC Drive Systems - Technical Guide No. 5". Technical Guides (ABB).
Re: "EMC Compliant Installation and Configuration for a Power Drive System - Technical Guide No. 3". Technical Guides (ABB).
Cblambert ( talk) 21:10, 12 April 2012 (UTC)
Cblambert ( talk) 22:13, 12 April 2012 (UTC)
Cblambert ( talk) 22:58, 12 April 2012 (UTC)
What Bose has to say about power electtronics information is interesting:
Cblambert ( talk) 21:20, 17 April 2012 (UTC)
Re: Basics of AC Drives
Re: Motoring Ahead
Cblambert ( talk) 15:15, 18 April 2012 (UTC)
In case deletion of subject derivation should need to be restored, I have revised compared to last article version to read as follows:
"In principle, the inverter current and voltage outputs to the motor are respectively directly proportional to the motor torque and speed, whereas on the constant-voltage AC input to the VFD, the current is directly proportional to the power drawn by the motor. That is, neglecting VFD system losses and assuming unity power factor at AC input to VFD, U*I ~ T*N, where T = motor shaft torque, N = motor speed.
Neglecting losses assuming unity VFD input power factor, we have:
Given that 1.732*Ui is a constant, Ii = Tm*Nm/1.732*Ui and Ii ~ Tm*Nm; that is, AC current input to VFD is directly proportional to motor power."
Derivation has not enough to do with VFD operation. Unity power factor assumption for VFD input is approximately true for diode rectifier drives but not active switching device VFD front ends. As stated, derivation is not really relevant.
Cblambert ( talk) 18:21, 15 April 2012 (UTC)
As a matter of interest, number of watchers of VFD article (~65) is about 4 times less than transformer and motor articles (each ~245). I don't know exactly what you make of this but others may have insights worth sharing. Cblambert ( talk) 20:22, 18 April 2012 (UTC)
added information on four quadrant control Shrikanthv ( talk) 08:07, 19 April 2012 (UTC)
Electric motor speed-torque chart is incorrect:
The image copies the same mistake as 'Basics of AC Drives' 4-quadrant speed-torque chart and is likely violation of copyright. Cblambert ( talk) 20:18, 19 April 2012 (UTC)
Image should be labelled to match this text:
Cblambert ( talk) 02:48, 20 April 2012 (UTC)
Some of the information regarding regeneration and braking were got from the links below , why are they being considered commercial links and being deleted ? please discuss
1) http://kimo.de/index.php?file=produkte/fu/u2/PB-TU2-06-08-22.html&menu=6&nav=1&lang=EN 2) http://kimo.de/index.php?file=anwend/kostenfu/PRO-Kosten-FU.html&lang=EN
It is true company related articles does contain wordings like , this is best suitable ... but i do believe information outwieghs the possible 'loss' Shrikanthv ( talk) 08:09, 20 April 2012 (UTC)
The sourcing in this article needs some work. In particular there is one [citation needed] tag and some paragraphs have no citations at all. The citation style is also a bit confusing (why are there references linked on their own line below the headings. The multiple citations (although not strictly a criteria) could be reduced. A large number of citations following a sentence tend to suggest the presence of original research and make reading the prose difficult. AIRcorn (talk) 04:13, 17 May 2012 (UTC)
GA toolbox |
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Reviewing |
Reviewer: Pyrotec ( talk · contribs) 14:03, 17 May 2012 (UTC)
I've had a quick read of the article and now I'm going to work my way through the article section by section, but leaving the WP:Lead until the end of the article.
On the basis of this quick reading, the article appears to have sufficient material to be considered for GA-status; but further improvements will be needed to obtain GA status this time round. For example: the current Lead is non-compliant with the requirements of WP:Lead since it is only provides an introduction for the article and makes no effort to summarise the main points. (I shall be covering this later in detail). There are also whole paragraphs, such as the first paragraph of Energy savings subsection of Benefits, that are unreferenced. The grammar/prose in some sentences is poor.
The requirements for GA can be found in WP:WIAGA, which is what I will be assessing the article against.
... to be continued. Pyrotec ( talk) 17:27, 20 May 2012 (UTC)
... to be continued. Pyrotec ( talk) 12:49, 19 May 2012 (UTC)
Drive type | DC | VFD | VFD | VFD |
---|---|---|---|---|
Criteria | Brush Type DC | AC V/Hz Control | AC Open-Loop Vector | AC Closed-Loop Flux Vector |
Typical speed regulation (%) | 0.01 | 1 | 0.5 | 0.01 |
Typical speed range at constant torque | 0-100 | 10-100 | 3-100 | 0-100 |
Min. speed at 100% torque (% of base) | Standstill | 8% | 2% | Standstill |
Multiple-motor operation recommended | No | Yes | No | No |
Fault protection (Fused only or inherent to drive) | Fused only | Inherent | Inherent | Inherent |
Maintenance | (Brushes) | Low | Low | Low |
Feedback device | Tachometer or encoder | N/A | N/A | Encoder |
...stopping for now. To be continued. Pyrotec ( talk) 19:01, 19 May 2012 (UTC)
...stopping for now. To be continued. Pyrotec ( talk) 21:31, 19 May 2012 (UTC)
...stopping for now. Pyrotec ( talk) 09:33, 22 May 2012 (UTC)
Pyrotec ( talk) 12:24, 23 May 2012 (UTC)
GA review – see WP:WIAGA for criteria
I'm awarding this article GA status. Congratulations on producing what is now fine article. Pyrotec ( talk) 11:37, 25 May 2012 (UTC)
I'm awarding this article GA status. Congratulations on producing, what is now, a fine article. Pyrotec ( talk) 11:37, 25 May 2012 (UTC)
I am going to rewrite lead section matching with wiki guidlines Shrikanthv ( talk) 11:49, 24 May 2012 (UTC)
Please check revert back on new edits on Lead section , hope it is now matching wiki guidlines
Shrikanthv (
talk) 11:05, 25 May 2012 (UTC)
Can we talk why the lead is being reverted back after getting GA ? , while the current (which was previous one ) did not match with GA guidlines Shrikanthv ( talk) 15:31, 25 May 2012 (UTC)
Good article - obviously lots of thought and time spent. However the "stiffness" query was never answered ( Thévenin's theorem article has no mention). I concede that to anyone with any exposure to AC circuit theory it's an obvious metaphor, but we cannot assume that background. So I propose the following edit to the first appearances...stiff voltage [low impedance]...stiff current [high impedance]. Note the links to the Impedance article. Shannock9 ( talk) 09:55, 26 August 2013 (UTC)
I have a concern that I'm not knowledgeable enough to resolve.
Probably quite unintentionally by its authors, the article tone comes over (on the surface) to be generally skewed towards promoting these devices, or making them sound desirable or a significant opportunity, rather than merely factual info about that topic. For example -
Perhaps these aspects of the topic can be better covered under a section "VFD market and adoption" - they are relevant to the topic, but placed as they are, it comes over as pushing this angle rather than providing encyclopedic coverage. FT2 ( Talk | email) 07:20, 9 October 2015 (UTC)
The lead section of this article is extremely difficult to fathom:
VFDs are used in applications ranging from small appliances to the largest of mine mill drives and compressors. However, around 25% of the world's electrical energy is consumed by electric motors in industrial applications, which are especially conducive for energy savings using VFDs in centrifugal load service,[5] and VFDs' global market penetration for all applications is still relatively small. That lack of penetration highlights significant energy efficiency improvement opportunities for retrofitted and new VFD installations.
I see no reason at all why the word "However" appears there, the term "centrifugal load service" seems to be very obscure, and the end of the paragraph seems disconnected from the beginning of it. NotYourFathersOldsmobile ( talk) 02:11, 18 March 2016 (UTC)
VFD as in the volunteer fire department aaaaa jacques is dead — Preceding unsigned comment added by Plutonical ( talk • contribs) 21:49, 7 April 2018 (UTC)