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225kW Variable Speed Motor
13

225kW Variable Speed Motor

225kW Variable Speed Motor

(OP)
Hi All,
I was looking into some form of soft starter for a 225kW induction motor on a ship, when the thought of variable
speed drive came to mind.  As the motor is driving a pump, the thought of being able to regulate the starting current as well as having speed control would be a bonus.  
My question is: are induction motors suitable for use with a vsd?
Thank you in advance.

RE: 225kW Variable Speed Motor

Induction motors rated for ASD/VFD appliction can be used. But some of imporant featuers to be considered are:
Squirrel Cage Induction Motor
Voltage, kW, 3-phase (delta or Star connected), Hz, rpm
frame size, Service factor, premium efficiency, insulation class, duty, Temp Class, Motor shall be suitable for adjustable speed drive (ASD) application, Motor shall be NEMA design class.
The differance between ASD appliction induction motor to the normal induction motor is that in ASD application motors special attention is paid to the heat losses genrated due to modulation frequencies.

RE: 225kW Variable Speed Motor

2
To add to JitTiw's comments, when contemplating applying an adjustable speed drive (asd) to an induction motor, two more things need to be considered:
(1) Motor insulation, especially end-turn insulation. A motor that is rated for inverter duty has extra insulation on the wire and in the end-turns to stand the stresses of harmonic voltage spikes and,
(2) Motor cooling. Do not attempt to operate a normal TEFC (totally enclosed fan cooled) motor anywhere near rated load at much less than 70% base speed, since the motor will not have sufficient air flow across the motor. A separately cooled motor (with blowers) can be operated at rated load at much lower speeds.

Hope this helps.

RE: 225kW Variable Speed Motor

2
From a practical standpoint, there are thousands of applications where AFDs have been added to existing induction motors.  

There can be problems, but generally they work.  The most important issue to me is motor overheating.  If the motor has to output the full 225 kW continuously you should make sure it has an adequate safety factor.  The harmonic components in the drive output increase motor heating.  

But most motors are not applied at their full output rating so this usually isn't a problem.  

The drive output does increase the voltage stresses on the windings so if buying a new motor, you would want to purchase an inverter-duty motor which should have better winding insulation.   

But in general, induction motors are what AFDs are intended be used with.  

RE: 225kW Variable Speed Motor

Suggestion: Considering various electronic equipment close proximities on a ship, it may be a good idea to trace the Electromagnetic Interference of the VSD. Some filtering may be needed and proper equipment grounding. This is usually available in the VSD specifications, application notes or from the VSD Tech Support.

RE: 225kW Variable Speed Motor

4
Anode:

You stated that the 225 kW motor drives a pump.

Is the pump a centrifugal or positive displacement (piston, vane, etc.) type ?

Also, please advise the motor voltage rating.

Thanks.

RE: 225kW Variable Speed Motor

(OP)
Hi jOmega,

The pump is centrifugal and the power supply is 440V 60Hz.  

Cheers

RE: 225kW Variable Speed Motor

hi...
lots of discussion on VFD, VSD, Inverter Duty Motors and Soft Starters on this forum...take same time to search for them..you will gain more information before you make a decision

good luck
dydt

RE: 225kW Variable Speed Motor

Anode,
There are many ships at sea with VFD's driving various applications. Some are centrifugal pumps, some are bow thrustors, some are anchor winches, etc.

I would say from experience that you most likely can apply a VFD to the existing motor without having to suffer the additional expense of replacing the motor with a "VFD rated) motor.  This is a variable torque application and so, as you reduce the speed, the load drops off as the square of the speed, and the power drops off as the cube of the speed. Ergo, as you reduce the operating speed, the cooling requirements are reduced accordingly.

[If this were an constant torque application; i.e., anchor winch or positive displacement pump, the answer would be different.]

Having done this many times before and not having suffered any known failures, I offer one suggestion; add a dv/dt (du/dt) filter at the output of the VFD. The VFD output connects to the filter input and the motor connects to the filter output. The filter will ensure that the voltage stress on the motor will be minimal. The concern here is that the insulation of the motor windings has aged and is more prone to voltage stress failure syndrome.

Some recommendations are: TCI's KLC filter (http://www.transcoil.com)  or a Schaffner du/dt filter.

I'd also suggest that your specification for an appropriate VFD include the requirment that the fundamental RMS output voltage not be less than 95% of the fundamental RMS input voltage to the VFD. Some (not all) VFD manufacturers add a wee bit of 3rd harmonic injection and or limited overmodulation techniques to improve the fundamental RMS output voltage. PWM VFDs that do not utilize such techniques, can suffer up to a 15% loss in fundamental RMS output voltage.   

Be sure to size the VFD based upon matching the VFD output rating to the motor nameplate amps. Remember, kW (HP) are nominal terms. All VFDs, in fact, all drives are ultimately rated in their output amperage sourcing capability.

Hope this helps.

jOmega  

RE: 225kW Variable Speed Motor

JBartos:

After visiting the references you posted above, I am curious as to how they are related to the topic of this discussion thread; to wit, applying a VFD to a shipboard centrifugal pump application.

In reading the comments presented in your first reference,
      http://www.control.com/1026163808/index_html
I was appalled at the incorrect statements about VFDs and their operation of ac induction motors presented by Mr. Hinton.  Not Good.

Your third reference....
     http://www.wegelectric.com/Newletters/Newsletter.pdf
provides no technical information to enhance this discussion thread, other than to advise that WEG makes VFDs, soft starters, and full voltage starters. Did I miss something ?

The reference to ...

http://www.esmagazine.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2503,11143,00.html

Timothy Coyle's article, is questioned as to relevance to this discussion thread.  It pertains to lockout device between controller and motor and certainly is not relevant to Anode's shipboard application

Perhaps I am missing your point or the value of your contribution to this disucssion thread. If so, I look forward to your comments.

RE: 225kW Variable Speed Motor

Comment on jOmega (Electrical) Dec 31, 2002 marked ///\\\:

After visiting the references you posted above, I am curious as to how they are related to the topic of this discussion thread; to wit, applying a VFD to a shipboard centrifugal pump application.
///The original posting poses a generic question: My question is: are induction motors suitable for use with a vsd?
My postings attempt to answer it over the web links that are efficiently broadening horizons, not always 100% accurately. The 100% accuracy is met very rarely in more popular postings.\\\
In reading the comments presented in your first reference,
      http://www.control.com/1026163808/index_html
I was appalled at the incorrect statements about VFDs and their operation of ac induction motors presented by Mr. Hinton.  Not Good.
///Certainly, you are entitled to your own opinion and expertise. I think that Mr. Hinton overall posting has its merit. I agree that "They can give DC boost for helping overcome breakaway torque and they can run the motor at full torque at any speed from 50% to 150% of the motor name plate speed." is somewhat irregular posting.\\\
Your third reference....
     http://www.wegelectric.com/Newletters/Newsletter.pdf
provides no technical information to enhance this discussion thread, other than to advise that WEG makes VFDs, soft starters, and full voltage starters. Did I miss something ?
///I presented this website to contribute an answer to the basic question posted in the original posting. The website categorizes products, it pertains to a prestigeous manufacturer, and it may be followed through the direct contact at the manufacturer.\\\

RE: 225kW Variable Speed Motor

My previous posting continued:
The reference to ...
http://www.esmagazine.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2503,11143,00.html

Timothy Coyle's article, is questioned as to relevance to this discussion thread.  It pertains to lockout device between controller and motor and certainly is not relevant to Anode's shipboard application
///I found the following relevant to the basic question in the original positing:
"Don't forget that variable-frequency-drives (vfd's), dc drives, "soft starters," and other electronic devices that supply power to motors are considered motor controllers under the NEC and must have a disconnect within sight. Modern vfd's are installed close to the motor to avoid over-voltage problems, making it difficult to keep all the vfd's in a mechanical room within sight of a single distribution panel or MCC.

As with starters, to reduce cost and size, most vfd manufacturers do not provide a disconnect switch as part of their standard drive package. If the optional input disconnect is not specified, a separate switch or circuit breaker must be installed. \\\

Perhaps I am missing your point or the value of your contribution to this disucssion thread. If so, I look forward to your comments.
///Suggestion: Please, would you post the more constructive criticism next time.\\\

RE: 225kW Variable Speed Motor

JBartos:
 
[blue] Timothy Coyle's article, is questioned as to relevance to this discussion thread.  It pertains to lockout device between controller and motor and certainly is not relevant to Anode's shipboard application[/blue]

///I found the following relevant to the basic question in the original positing:
"Don't forget that variable-frequency-drives (vfd's), dc drives, "soft starters," and other electronic devices that supply power to motors are considered motor controllers under the NEC and must have a disconnect within sight. Modern vfd's are installed close to the motor to avoid over-voltage problems, making it difficult to keep all the vfd's in a mechanical room within sight of a single distribution panel or MCC.


I think you missed the point .... so, here it is again.

Anode said: "I was looking into some form of soft starter for a 225kW induction motor on a ship, when the thought of variable speed drive came to mind."

JBartos, Anode's application is aboard a ship[/].
The NEC Doesn't Apply to SHIPS !
...and so, my comments about the appropriateness of the Coyle reference stand.

Using a refrence to a non-relevant NEC requirement serves what purpose ? ? ? ?

Perhaps you'd consider starting a new thread for such side trips, so as not to obfuscate the salient points of this discussion.

 

RE: 225kW Variable Speed Motor

Suggestion to/Comment on the previous posting: The following is an excerpt from NFPA 70-2002 National Electrical Code:
Not Covered. This Code does not cover the following:
(1) Installations in ships, watercraft other than floating
buildings, railway rolling stock, aircraft, or automotive
vehicles other than mobile homes and recreational vehicles
FPN: Although the scope of this Code indicates that the
Code does not cover installations in ships, portions of this Code are incorporated by reference into Title 46, Code of Federal Regulations, Parts 110–113.

Therefore, I considered the NEC related to ships.

RE: 225kW Variable Speed Motor

JBartos,

Nice Try, JB. But your logic is faulty. A minor reference within... does not make the entire spec apropos.

As you yourself stated: [blue]" Although the scope of this Code indicates that the Code does not cover installations in ships..." [/blue]  

Even the NEC states that it does not cover installations in ships ... as you stated.

Are you saying that we should ignore their pronouncements and denial of applicability... and accept your faulted logic based upon a general and minimal citing? I think not.  

And in particular, Timothy Coyle's article is absolutely not appropriate for shipboard use. That is the issue, sir.

Using your logic, would it not be correct to say that because I use your name.... I know you personally ?  

I would also refer you back to your reference:
http://www.control.com/1026163808/index_html
where Mr. Hinton's erroneous comments have been exposed.

RE: 225kW Variable Speed Motor

Suggestion to the previous posting: The "minor reference within" just remains to be seen how minor it is. Certainly, you are entitled to have your own opinion. That does not mean that you have right to impose it on other(s) at any price. By any chance, who gave you that right?

RE: 225kW Variable Speed Motor

JBartos,

I'm afraid that you give me more power than I possess. I don't determine if its a minor or major reference. That is done by those that write the specs and standards.  

If you cannot discern the difference between major and minor, then further discussion here is moot.

Suffice it to say, (and I am not the only one to bring this to your attention) but your post display a pattern of throwing things into a discussion that have little relevance to the main theme of the discussion.  Others have noted this and brought it to your attention.  I would suggest that before posting impertinent items and references, that you carefully consider the relevance to the discussion.  Remember, that the original poster is looking for answers and knowledge; not obfuscation.

Suggestion to JB:  Ascertain the relevance before posting references culled from the fruits of search engines.

If you feel it beneficial to take a side trip, then please do start a new thread. This particular one has become a mess with a lot of rhetoric wasted correcting misconceptions masquerading as fact.

My apologies to the others who have had to suffer thru this.

RE: 225kW Variable Speed Motor

Anode,

I have done some research into this in the last year for several installations.  I had an application where I had to change a 200 hp pump from steam driven to electric driven.  Normally for shipboard use you would get a motor specified for 50 degree C temperature rise and this is sufficient for VFD use.  

RE: 225kW Variable Speed Motor

Suggestion: Besides the VFD output dv/dt filters, as posted by JOmega, there are also harmonic filters for the VFD output, e.g. HarmonicGuard available at:
http://www.transcoil.com
http://www.transcoil.com/#khg
These harmonic filters trap or mitigate harmonic content on the VFD output. To have a peace of mind, one might check the VFD output for voltage harmonic content and current harmonic content. If it is high, the HarmonicGuard or equal is recommended to extend the life expectancy of the motor powered by the VFD.
 

RE: 225kW Variable Speed Motor

Anode,
Slings and arrows aside, there was good advice from both parties buried in the above posts. I for one do not recommend immediately replacing standard induction motors when VFDs are added. You already own that motor, why not see if it works out OK? As Jomega indicated, the vast majority do, as long as some prudent precautions are taken, i.e. the filtering that he mentioned. IMHO, do not even consider a VFD without considering filtering. And speaking of that, jbartos made a good point earlier about nearby electrical equipment getting interference. Think of a VFD as a good sized FM radio transmitter. On shipboard that can be problematic. Take all of your application information and concerns to a filter supplier and do not skimp. Do NOT trust the VFD manufacturer to do this for you. For the most part they have a different agenda, namely that you buy the VFD. If possible, hire an integrator with experience in this field. You will be successful.

Quando Omni Flunkus Moritati

RE: 225kW Variable Speed Motor

Hello Anode

Anode,induction motors and VFDs are employed on a multitude of applications world over.If you have a need for a VFD.somebody will come up with one to suit your application.
I was very impressed by the capabilities of Magnectic Couplings manufactured by MAGNA DRIVES.These devices provide great spped control,no physical connection from Driver to Driven load and can be controlled by a simple remote 4 /20 mA from a PLC.It can use a standard Induction motor and no worries about Harmonics,filtering and all the other things associated with VFDs.This Technology is fairly new ,but I believe we all will be hearing about it more in the future.They can go as high as 1500 Hp and if I was looking for an adjustable speed system to drive a pump,I would definitely look into it.

Good Luck.  

GusD

RE: 225kW Variable Speed Motor

To correct a mis-conception from JB's post on the TCI  HarmonicGuard  filter; it is designed for mitigation of the 5th harmonic on the line (mains) side of the VFD in attempt to attain compliance with IEEE 519-1992. It is not designed for use at the output of the drive or for dv/dt (du/dt) reduction.

The KLC filter from TCI (TransCoil Inc) is the product intended to reduce dv/dt (du/dt) at the motor. The filter is applied at the output of the VFD and the motor is connected to the filter.

See: KLC Drive Output Filters
http://www.transcoil.com/#klc

They also make a sinewave filter that filters the PWM voltage pulses into a sinewave voltage for application to the motor. In addition to dv/dt(du/dt) reduction, the filter also attenuates the audible noise produced in the motor by the VFD switching frequency and its harmonics.
Note: While this filter will virtually eliminate the audible noise in the motor, the magnetics in the filter will sing.... If that is a concern, contact TCI for an engineered solution that applies some dampening techniques to the inductors.

See:  MotorGuard - KMG Sine Wave Filter
http://www.transcoil.com/#kmg

RE: 225kW Variable Speed Motor

Anode,
     After reading your other threads, you either work for a shipbuilder or consult with one. I guess this application is for large ship, +400 feet long. I would definitely check out the U.S.Coast Guard electrical regulations and the U.S.Navy's "Navsea" department(the are responible for Navy engineering and regulations.
     You also might want look for a component that meets "military specification" (mil-spec for short).
     It has been 10 years since i have been on a boat, but I remember "mil-spec" equipment being pretty robust.

Regards,
Afterhrs         

RE: 225kW Variable Speed Motor

(OP)
Afterhrs,

You are right on all counts.  I am currently working in a shipyard as a consultant for a tanker (750 feet) conversion.
I used to be in the military myself and appreciate the "mil-spec" construction criteria.  Thanks for the tips, and to everyone else here who has contributed.

Cheers
Anode
 

RE: 225kW Variable Speed Motor

Suggestion to jOmega (Electrical)    Aug 10, 2003 marked ///\\\
To correct a mis-conception from JB's post on the TCI  HarmonicGuard  filter; it is designed for mitigation of the 5th harmonic on the line (mains) side of the VFD in attempt to attain compliance with IEEE 519-1992.

///Yes, this is true. However, it may be used on the VFD output side to mitigate harmonics as I posted in my previous posting that is criticized by jOmega.\\\

 It is not designed for use at the output of the drive or for dv/dt (du/dt) reduction.

///Yes, agree. I never stated anywhere that it is used for that purpose. In fact, I indicated in my posting:
"Besides the VFD output dv/dt filters, as posted by JOmega, there are also harmonic filters for the VFD output, e.g. HarmonicGuard available at:
http://www.transcoil.com
http://www.transcoil.com/#khg"\\\

The KLC filter from TCI (TransCoil Inc) is the product intended to reduce dv/dt (du/dt) at the motor. The filter is applied at the output of the VFD and the motor is connected to the filter.

///Never disputed, never denied. I am very familiar with these filters and their purpose in VFD context.\\\

See: KLC Drive Output Filters
http://www.transcoil.com/#klc

They also make a sinewave filter that filters the PWM voltage pulses into a sinewave voltage for application to the motor. In addition to dv/dt(du/dt) reduction,

///This feature is not associated with the KMG filter. It is associated with "dV/dTGuard KLC Filter Motor-Protecting Output Filter"
http://www.transcoil.com/#klc
""The dV/dTGuard product family has been designed as an engineered solution for motor failures due to the reflected wave phenomenon.""\\\

 the filter also attenuates the audible noise produced in the motor by the VFD switching frequency and its harmonics.

///To correct jOmega misconception, the following is stated at
http://www.transcoil.com/#kmg
""The KMG filter is designed to attenuate the carrier components present in the output waveform of typical PWM output power supplies.""
See:  MotorGuard - KMG Sine Wave Filter
http://www.transcoil.com/#kmg
\\\

Note: While this filter will virtually eliminate the audible noise in the motor, the magnetics in the filter will sing.... If that is a concern, contact TCI for an engineered solution that applies some dampening techniques to the inductors.

See:  MotorGuard - KMG Sine Wave Filter
http://www.transcoil.com/#kmg

///To summarize the corrections (and misconceptions posted by jOmega):
1. dV/dTGuard KLC Filter Motor-Protecting Output Filter"
http://www.transcoil.com/#klc
is to mitigate dV/dt effects

2. MotorGuard - KMG Sine Wave Filter
http://www.transcoil.com/#kmg
is to mitigate carrier frequency components and associated harmonics.

3. HarmonicGuard available at:
http://www.transcoil.com/#khg
is to mitigate harmonics on the VFD input. However, it is designed to mitigate harmonics in general. Harmonics due to wave distortion caused by the VFD switching topology are still present on the VFD output. There are oscilloscope traces available of some manufacturers VFD outputs. Also, the harmonic content is possible to measure on the VFD output by the harmonic analyzer. It appears that jOmega is not aware of this.\\\

RE: 225kW Variable Speed Motor

Sorry JB, but the knowledgable folks at TCI state that the HarmonicGuard Filter is NOT DESIGNED to be used on the output of the VFD.....period. You'll fry it!   Components not selected/rated for frequency components present in the output of the VFD.

If you'd like, I'll be happy to put you in touch with their VP Engineering who can explain it to you . Perhaps then you'll believe me when I tell you that it cannot be used at the output of VFDs....

And JB.... here is what you said.... and I quote (in blue):

"jbartos (Electrical) Jun 25, 2003
Suggestion: Besides the VFD output dv/dt filters, as posted by JOmega, there are also harmonic filters for the VFD output, e.g.
HarmonicGuard available at:
http://www.transcoil.com";

 

JB you also made the same error in your Aug 16. post above,  in several places..... and I quote (in blue) ....

"jbartos (Electrical) Aug 16, 2003
Suggestion to jOmega (Electrical)    Aug 10, 2003 marked ///\\\
{jO said}To correct a mis-conception from JB's post on the TCI  HarmonicGuard  filter; it is designed for mitigation of the 5th harmonic on the line (mains) side of the VFD in attempt to attain compliance with IEEE 519-1992.{end jO's comment}

{JB said}///Yes, this is true. However, it may be used on the VFD output side to mitigate harmonics as I posted in my previous posting that is criticized by jOmega.\\\ {end JB comment}

 {jO comment} It is not designed for use at the output of the drive or for dv/dt (du/dt) reduction."{end jO comment}


{JB comment} "///Yes, agree. I never stated anywhere that it is used for that purpose. In fact, I indicated in my posting:
"'Besides the VFD output dv/dt filters, as posted by JOmega, there are also harmonic filters for the VFD output, e.g. HarmonicGuard available at:
http://www.transcoil.com";'



Here again, JB, you stated that the HarmonicGuard filter could be used at the VFD OUTPUT

Which as I said previously and above, is just not true. The HarmonicGuard CANNOT be used at the output of any VFD. It is designed SOLELY for use on the 50/60 HZ mains.

The issue JB, is NOT whether or not the filter is servicable for dv(du)/dt reduction or whether it is for harmonic reduction;  the issue is that it is NOT designed to be used on the output of VFDs. The HarmonicGuard Filter, as the engineers at TCI will tell you, is designed ONLY for use on 50/60 Hz Mains; and must never be connected  the output of a VFD else it will cause damage to the HarmonicGuard filter.

JB, I hope you understand that now. If not contact me at jomega@email.com with a phone number at which you can be reached and I'll be happy to have a TCI engineer contact you to reiterate the reasons why the HarmonicGuard filter cannot be connected to the output of a VFD.  

I'm sure you don't want to see someone misapply the HarmonicGuard filter and damage it and/the VFD it is mistakenly connected to, now do you?

Ok ? Are we clear on the use and non-use of the HarmonicGuard filter ?

NEXT....  you said (in your Aug. 16 post above.. and I quote in blue...


{jO comment} See: KLC Drive Output Filters
http://www.transcoil.com/#klc

They also make a sinewave filter that filters the PWM voltage pulses into a sinewave voltage for application to the motor. In addition to dv/dt(du/dt) reduction, {end jO comment}

{JB comment}///This feature is not associated with the KMG filter. It is associated with "dV/dTGuard KLC Filter Motor-Protecting Output Filter"{end JB comment}


Well, JB, you leave me no choice but to take issue with you again.... In a meeting at TCI about 4 weeks ago, their chief engineer stated that the KMG filter does indeed attenuate dv/dt and does so very nicely. You see, the KMG is a low pass filter design, and its output is virtualy sinusoidal. Ergo, it does not introduce step voltages (with steep wave fronts) into the wiring between the drive and motor that exhibits transmission line or tank circuit (your choice)characteristics and produces standing waves therein.  As I said, the output of the KMG is a pretty good sinewave at fundamental frequency.... and so...effects DV/DT reduction at the motor...

Ok ?  If not we can include this in the phone call to you from TCI....


And finally, JB, your last statements.... quoted below in blue...


3. HarmonicGuard available at:
http://www.transcoil.com/#khg
is to mitigate harmonics on the VFD input. However, it is designed to mitigate harmonics in general. Harmonics due to wave distortion caused by the VFD switching topology are still present on the VFD output. There are oscilloscope traces available of some manufacturers VFD outputs. Also, the harmonic content is possible to measure on the VFD output by the harmonic analyzer. It appears that jOmega is not aware of this.\\\



JB, the HarmonicGuard is designed as a somewhat broadly tuned 5th harmonic trap. Broadly because there's some spillover to catch some of the 7th... as well as covering the 5th on 50 Hz mains ...

It is not, as you stated, a harmonic reduction filter; it is a trap filter for limited, specific frequencies....i.e the 5th harmonic of the mains fundamental frequency.

It won't do squat for you on the output of the VFD which has much higher frequency content, other than fry....


p.s.... JB, the KLC filter doesn't do squat for removal of audible noise from the motor.... That filter rolls of somewhere in the 20-30 kHZ range....filter is designed to produce some softening of the wavefronts of the output voltage pulses from the VFD.

We can also include this in the discussion with TCI .... I'll let them set you straight on this as well.







RE: 225kW Variable Speed Motor

A bit late in repsonding but an interesting discussion all the same. As product manager for a large drives company, I thought I'd offer a few points:
1) First the motor issue. There's been no mention of supply voltage. If your supply voltage is >500V then be very careful fitting a VSD (or ASD if you prefer!). If you go for a PWM (Pulse Width Modulating) drive (the most common) then the peak to peak voltage spikes will very quickly cause problems on motors rated at >500VAC. Check the manufacturer of the motor!
2)Onto the VSD. Be very careful when applying VSD's due to the increased leakage current you will get from all makes unless the design of the drive has been specially looked into. Generally this means quite a level of board isolation to ensure any internal filtering has the minimum leakage. We try and achieve something in the region of 2mA max.
3) If you have to fit an RFI(Radio Frequency Interference) Filter as somebody suggested in the threads, make sure it has been specifically designed so that the Y (wye) capacitor has been disabled (cut). This reduces the high leakage current from a filter that is basically made up of capacitors. The supplier of the drive will know what you mean (there's a test for them!)
Why is leakage current a problem? well, if you know about ships you will know the answer but for those in the thread who don't, it rots the hull. Most(all I think)ships have a sacrificial cathode that will basically absord any leakage current and this will rot away rather than the hull, but it is very expensive and ship owners would rather not have it go too quickly as their maintenance costs rise rapidly.
I'm sure there are other reasons but this seems to be the main one from a drives developers point of view with ships in mind.
4) There are various standards and approvals ship manufacturers will role out with regards putting electrical devices on their vessel. One is DNV (Det Norske Veritas). This demands the drive to be stamped up with DNV and to be issued with a certificate to say you have paid the extortionate fees demanded by DNV. The other is Lloyds approval.  This is another tortuous route drive manufacturers have to go down. Necessary but very costly. Insurance companies rule the waves!
There are very few companies who have dared go down this route. Siemens is one (ok, you found me out) but Danfoss and Vacon are others. I would imagine ABB do but I am only aware of their large MW propulsion drives that are part of the ship anyway.
5) There's been a lot of mention of harmonic filters and the like. I would check with the manufacturer to see if they have the absolute minimum leakage current as the majority of passive harmonic filters include a fair proportion of capacitors.

I trust this doesn't scare you off. A VSD should always be supplied to give you control. A by-product of good control is energy savings. People like talking about energy savings because the accountants in companies can see return on their investment. The ROI can be anything from 6 months +, usually the '+' increases due to badly applied drives! Always go with a reputable drive company, they should always provide the balance!

RE: 225kW Variable Speed Motor

Dear sed2developer,

I have been looking for data on corrosion caused by VFDs for some time now. You seem to have some references. Could you please share them with us in this thread? My interest is not only in shipping, but in pumps, seals etcetera.

RE: 225kW Variable Speed Motor

Comment on jOmega (Electrical)    Aug 17, 2003 marked ///\\\
Sorry JB, but the knowledgable folks at TCI state that the HarmonicGuard Filter is NOT DESIGNED to be used on the output of the VFD.....period. You'll fry it!   Components not selected/rated for frequency components present in the output of the VFD.
///Surprise, surprise. The output of the VFD by applying the applicable TCI filter is supposed to be almost ideal sinusoidal wave. Then, it is said that the ideal sinusoidal wave would fry the HarmonicGuard Filter. This does not make any sense. What good is the HarmonicGuard if it cannot withstand the almost pure sinusoidal wave?\\\
If you'd like, I'll be happy to put you in touch with their VP Engineering who can explain it to you . Perhaps then you'll believe me when I tell you that it cannot be used at the output of VFDs....
///I would not engineer and design the HarmonicGuard in front of:
"dV/dTGuard KLC Filter Motor-Protecting Output Filter"
and
"MotorGuard - KMG Sine Wave Filter"
since these are designed to mitigate higher frequency contaminations.\\\

And JB.... here is what you said.... and I quote (in blue):
"jbartos (Electrical) Jun 25, 2003
Suggestion: Besides the VFD output dv/dt filters, as posted by JOmega, there are also harmonic filters for the VFD output, e.g. HarmonicGuard available at:
http://www.transcoil.com";;

JB you also made the same error in your Aug 16. post above,  in several places..... and I quote (in blue) ....
///Just make sure that you do not make errors. See my first comment above.\\\
"jbartos (Electrical) Aug 16, 2003
Suggestion to jOmega (Electrical)    Aug 10, 2003 marked ///\\\
{jO said}To correct a mis-conception from JB's post on the TCI  HarmonicGuard  filter; it is designed for mitigation of the 5th harmonic on the line (mains) side of the VFD in attempt to attain compliance with IEEE 519-1992.{end jO's comment}

{JB said}///Yes, this is true. However, it may be used on the VFD output side to mitigate harmonics as I posted in my previous posting that is criticized by jOmega.\\\ {end JB comment}

 {jO comment} It is not designed for use at the output of the drive or for dv/dt (du/dt) reduction."{end jO comment}
///I never stated that the HarmonicGuard is to be solely applied on the VFD output. This is where things are becoming twisted by J.Omega.\\\
{JB comment} "///Yes, agree. I never stated anywhere that it is used for that purpose. In fact, I indicated in my posting:
"'Besides the VFD output dv/dt filters, as posted by JOmega, there are also harmonic filters for the VFD output, e.g. HarmonicGuard available at:
http://www.transcoil.com";;'

Here again, JB, you stated that the HarmonicGuard filter could be used at the VFD OUTPUT
///Yes, I justified my reasoning behind it in my first reply above.\\\
Which as I said previously and above, is just not true. The HarmonicGuard CANNOT be used at the output of any VFD. It is designed SOLELY for use on the 50/60 HZ mains.
///This does not sound credible that the HarmonicGuard would not withstand almost sinusoidal wave accomplished by other filters on the VFD output. In fact the harmonic currents are flowing from the motor into the HarmonicGard filter, the same way as on the VFD input side. Motor produces significant 5th, 7th and 9th harmonics. Where are these mitigated on the VFD output?\\\
The issue JB, is NOT whether or not the filter is servicable for dv(du)/dt reduction or whether it is for harmonic reduction;  the issue is that it is NOT designed to be used on the output of VFDs. The HarmonicGuard Filter, as the engineers at TCI will tell you, is designed ONLY for use on 50/60 Hz Mains; and must never be connected  the output of a VFD else it will cause damage to the HarmonicGuard filter.
///Please, see my comment above.\\\
JB, I hope you understand that now.
///I hope you understand now.\\\
 If not contact me at jomega@email.com with a phone number at which you can be reached and I'll be happy to have a TCI engineer contact you to reiterate the reasons why the HarmonicGuard filter cannot be connected to the output of a VFD.
///Perhaps, under some conditions.\\\  

I'm sure you don't want to see someone misapply the HarmonicGuard filter and damage it and/the VFD it is mistakenly connected to, now do you?
///I am more concerned about the 5th, 7th, 9th, etc. harmonics, that are not being treated on the VFD output or on the motor input. I do not see them addressed by J.Omega, TCI, etc. However, I did have them addressed during various VFD presentations by the VFD manufacturers, e.g. Magnetek in the past.\\\
Ok ? Are we clear on the use and non-use of the HarmonicGuard filter ?
///Far appart as at the beginning.\\\
NEXT....  you said (in your Aug. 16 post above.. and I quote in blue...

{jO comment} See: KLC Drive Output Filters
http://www.transcoil.com/#klc

They also make a sinewave filter that filters the PWM voltage pulses into a sinewave voltage for application to the motor. In addition to dv/dt(du/dt) reduction, {end jO comment}

{JB comment}///This feature is not associated with the KMG filter. It is associated with "dV/dTGuard KLC Filter Motor-Protecting Output Filter"{end JB comment}

Well, JB, you leave me no choice but to take issue with you again.... In a meeting at TCI about 4 weeks ago, their chief engineer stated that the KMG filter does indeed attenuate dv/dt and does so very nicely.
///This seems to be contradicting what is posted on TCI website and what I posted above, namely:
1. dV/dTGuard KLC Filter Motor-Protecting Output Filter"
http://www.transcoil.com/#klc
is to mitigate dV/dt effects
\\\
 You see, the KMG is a low pass filter design, and its output is virtualy sinusoidal. Ergo, it does not introduce step voltages (with steep wave fronts) into the wiring between the drive and motor that exhibits transmission line or tank circuit (your choice)characteristics and produces standing waves therein.  As I said, the output of the KMG is a pretty good sinewave at fundamental frequency.... and so...effects DV/DT reduction at the motor...
///How comes that the HarmonicGuard would "fry" in such perfect conditions on the VFD output.\\\
Ok ?  If not we can include this in the phone call to you from TCI....
///Thank you for your services. I follow engineering and design. I would like to witness that "frying" of HarmonicGuard filter" on perfectly sinusoidal input.\\\
And finally, JB, your last statements.... quoted below in blue...
3. HarmonicGuard available at:
http://www.transcoil.com/#khg
is to mitigate harmonics on the VFD input. However, it is designed to mitigate harmonics in general. Harmonics due to wave distortion caused by the VFD switching topology are still present on the VFD output. There are oscilloscope traces available of some manufacturers VFD outputs. Also, the harmonic content is possible to measure on the VFD output by the harmonic analyzer. It appears that jOmega is not aware of this.\\\

JB, the HarmonicGuard is designed as a somewhat broadly tuned 5th harmonic trap.
///Are you aware that induction motor creates 5th harmonic on its input which flows toward the power supply?\\\
 Broadly because there's some spillover to catch some of the 7th... as well as covering the 5th on 50 Hz mains ...
///Are you aware that induction motor creates 7th harmonic on its input which flows toward the power supply?\\\
It is not, as you stated, a harmonic reduction filter; it is a trap filter for limited, specific frequencies....i.e the 5th harmonic of the mains fundamental frequency.
///Do you happen to know in which direction current harmonics flow? The HarmonicGuard filter mitigates harmonics flowing from the AC-DC converter (rectifier) to the input power supply. This is why there is IEEE Std 519.\\\
It won't do squat for you on the output of the VFD which has much higher frequency content, other than fry....
///Certainly, entitled to your own opinion and expertise.\\\

p.s.... JB, the KLC filter doesn't do squat for removal of audible noise from the motor.... That filter rolls of somewhere in the 20-30 kHZ range....filter is designed to produce some softening of the wavefronts of the output voltage pulses from the VFD.
///I posted the following information from the manufacturer web site in my previous posting, namely:
/This feature is not associated with the KMG filter. It is associated with "dV/dTGuard KLC Filter Motor-Protecting Output Filter"
http://www.transcoil.com/#klc
""The dV/dTGuard product family has been designed as an engineered solution for motor failures due to the reflected wave phenomenon.""\\\
We can also include this in the discussion with TCI .... I'll let them set you straight on this as well.
///I do not have to. I feel reasonably comfortable with what the TCI offers and advertises.\\\

RE: 225kW Variable Speed Motor

jbartos,

I think that your endless postings about anything and everything are getting very tiring. And the way you try to "prove" that you are always right are even more so. In this discussion (and many other) you seem to be unable to understand where your limits are.

I am sure that you have some expertise in some technical field (power transmission perhaps?) but what you are writing in this is pure non-sense.

Someone has to put an end to this.

RE: 225kW Variable Speed Motor

Yes! Inverter duty induction motor should be selected.

RE: 225kW Variable Speed Motor

Here's my two cents:

I generally agree with the above posts.  You can probably do a straight retrofit of your starter with a VFD.  Some notes on that:

1.  You should limit low speed -- someone else said to 70% of rated speed, I'd say maybe as low as 50%.  Check with your motor vendor.  No doubt about it, you cannot run your pump at full load and 10% speed all day.  The only gray area is just how low you can go and be OK.

2.  Switching speed (kHz) of the VFD has a big impact on efficiency, harmonics, ground currents (and hull rotting), motor life, etc.  Have a good long talk with both your motor and VFD vendor on this -- maybe.  Then again, there's a reasonable chance that you could neglect this and be OK if you're the gambling sort.

3.  Ground currents can pit or flute your motor bearings and downstream pump bearings.  You might want to investigate the installation of a shaft grounding device (essentially a grounded brush) to prevent that.  Then again, you can maybe forget about that and be OK.

I'm reasonably confident that if you pick a good number for the low-end motor speed, and if your distribution sytem is rather "big" compared to the size of the motor, that everything else will be OK.  You can spend as much time as you want checking out other potential problems and details.  But sooner or later there comes a point in every project where you have to shoot the engineer and start construction.

RE: 225kW Variable Speed Motor

jbartos,

I myself have laughed off your ridiculous replies to several of my threads. After reading this thread I now know I'm not the only one!!!

Are you gonna retire after you ten thousandth posting?? This will stop a lot of confusement all round!

Chill out & have a BUD!!!!!!

Alan

RE: 225kW Variable Speed Motor

Suggestion to skogsgurra (Electrical)    Oct 21, 2003 marked ///\\\
jbartos,
I think that your endless postings about anything and everything are getting very tiring. And the way you try to "prove" that you are always right are even more so. In this discussion (and many other) you seem to be unable to understand where your limits are.
///Certainly, everyone is entitled to once own opinion and expertise.\\\
I am sure that you have some expertise in some technical field (power transmission perhaps?) but what you are writing in this is pure non-sense.
///Unconstructive criticism.\\\
Someone has to put an end to this.
///Dictators.\\\

RE: 225kW Variable Speed Motor

Suggestion to Ahr35181 (Electrical)    Oct 21, 2003
jbartos,
I myself have laughed off your ridiculous replies to several of my threads. After reading this thread I now know I'm not the only one!!!
///I received some oscilloscope traces of VFD outputs that did not look to me as perfect sinusoids. I am basing my comments on many unique observations, papers, and theory, not on hearsays or postingsays.\\\
Are you gonna retire after you ten thousandth posting?? This will stop a lot of confusement all round!
///I volunteer postings for many reasons, not only one.\\\
Chill out & have a BUD!!!!!!
///I am not addicted to one particular brand of beer or postings.\\\
Alan

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