Centrifugal governor calculations

[neil cook]

Hello all,
I am having problems working out the weight I require for as braking system.

I have a wind unit bringing me 1kw of power through a standard generator. However the wind I catching is far stronger than my generator can take, anything over a KW will kill my unit so I decided to make a centrifugal governor/brake,. but I cannot work out how much weight I require to start the system braking once I reach the 1kw mark. Can anyone help?

 

[Cleonis]

However the wind I catching is far stronger than my generator can take, anything over a KW will kill my unit so I decided to make a centrifugal governor/brake,.

I did a ten second Google search, and in passing I noticed someone had designed a governor system where the governor adjusted the pitch of the blades, so that in high wind the blades would be less efficient, which would regulate the power output.

A governor that operates a brake, that doesn't seem like a good idea. To withstand wear it would need durable, expensive parts. Also, when in heavy use the brake system would be in danger of overheating.

I don't know how the problem of excessive power output in high wind is usually dealt with. Maybe the usual setup is to have a small windmill compared to the generator unit, so that the output will never overwhelm the generator, I don't know.

It just seems better design to regulate the amount of wind energy that is harvested in the first place. It doesn't seem a viable design to harvest all the wind energy, and then try to dump part of that energy by applying a brake.

 

[litup]

Wouldn't it be more efficient to design variable pitch windmill blades? If the pitch of the blades can be varied like aircraft, it seems obvious that would compensate for most any wind condition.

 

[litup]

Another way to look at it: Couple a second generator that kicks in only at a certain wind speed, that way you even get more power output. That would add braking due to generating more energy.

 

[neil cook]

Hello all,
thanks for your input so far.
The wind unit that I have does not have props or blades of any kind so the idea of changing the form of the blade to alter the air flow will not work.

The 1kw motor I have already attached was very expensive and to buy another is not in my budget or for that matter do I have space for another generator. The generator that I have at the moment I can run in wind speeds upto 20m/s and it would not happen that often to have wind at higher speeds so the second generator would not be used too often.

Thanks

 

[Cleonis]

Hello all,
thanks for your input so far.
The wind unit that I have does not have props or blades of any kind so the idea of changing the form of the blade to alter the air flow will not work.
[...]
The generator that I have at the moment I can run in wind speeds upto 20m/s and it would not happen that often to have wind at higher speeds .

I can only repeat my earlier concern: that in wind conditions where the power output is too big a brake system is likely to overheat . Brakes on cars are used only intermittently, so there's time for the heat to dissipate. But drive around a car on a circuit, overusing the brakes, and pretty soon the brakes will be red hot.

Your only option, it seems, is to create a runaway mechanism. When the slider of the centrifugal governor exceeds a particular position the brakes must start clamping down and gradually keep tightening, stopping the wind harvesting device, keeping your equipment and itself from harm. When the weather has calmed down again you can reset the system. From your message I understand that too much wind will happen only rarely.

I don't see a solution where governor regulated brakes are throttling the system. I think any risk of overheating should be eliminated.