Braking systems of industrial fans

N

Thread Starter

Newtothis

Does anyone know the control strategies usually used to apply the stopping brake of a fan? I am completing a final year project but can't find anything useful on the web.
 
Phil,

I have read about dc injection and regen breaking but I was more interested in the control methods used to apply an electro hydraulic brake

Do you know of any info?
 
NTT... What do you mean by "Control Methods?"

Do you mean your own design? Or Electronic Systems that are commercially available? Or Mecanical-Brakes similar to those in automobiles (which are somewhat electro-hydraulic?

Can you provide additional detail? Is your application related to a particular type of fan, i.e., a cooling-tower fan?

Phil
 
N

NewtothiPhil

Electronic systems that would apply an electro-hydraulic or mechanical brake. Do you know we're I could find some information?

Thanks
 
S
I think you need to tell us why the fan needs a brake in the first place. During a commanded stop? To keep ambient wind from backdriving the motor and overspeeding it or the gearbox?

If we knew why the fan needed braking, we'd probably have more helpful suggestions about what the appropriate control philosophy/strategy might be.
 
Sorry, this would be a commanded stop and once it has been stopped a handbrake would be applied.
 
It's, just the ordinary stopping command. What control strategies are used For this sequence?

Thanks
 
if it's across the line you can:

1) coast stop - i.e. just open up the contactor

2) use contactor to engage a braking circuit to stop (normally closed contacts). circuit would use resistors etc.

if it's on a vfd you can:
1) coast stop

2) use an internal/external braking transistor to bleed the energy to a braking resistor

3) use dc injection

4) regen to the line depending on hardware you have

normal is relative. there are a lot of way to brake a motor. please tell us what you are doing and we can hit the normal target much closer. until then we are just giving ideas.
 
Newtothis,

> It's, just the ordinary stopping command. What control strategies are used For this sequence?

It would be most helpful if you would tell us why it's necessary for the fan to stop turning quickly or be prevented from turning when commanded to stop. Many applications don't require the fan to stop quickly or to be braked to a stop or be held stationary when stopped. You haven't provided enough information about the requirements of the application (why the fan needs to be stopped quickly, or if it needs to be held stationary when stopped).

It would be most helpful if you would tell us about the size of the fan motor (HP; KW; etc.) and what the fan does and why it needs to stop so suddenly or be held stationary. As has been said, there are many techniques and methods, and the one that's best for your application depends on the application. So, if you tell us about the application, the size/energy of the equipment involved, you will likely get a more concise response. There are even disc brakes which can be used on some larger applications to slow rotation (brake) and then hold the fan rotor stationary. But, that's not the perfect solution for every situation.

Tell us as much as you can about the problem you are trying to solve, and the equipment involved, and you will likely get the best response.

As has been said, until then the responses will just be guesses.

Help us to help you.
 
N
Thanks for all the replies, what it is i am writing a literature review of the various braking techniques DC current injection etc and how these apply to fans. Any information you can spare would be most helpful. I have also read about electro hydraulic brakes but is there any information on the brake disc.

Thanks new to this
 
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