Homebrewed Electricity > Wind

My home made Asynchronous Induction generator PLC controller (image heavy)

<< < (3/4) > >>

projectpower:
coolies

StorminN:
Very neat stuff, Jon. I'm a newbie to wind generators, but from the tip brakes and downwind design of those turbines in your first picture, I thought they might be Enertechs...
I don't have the manual here, but if memory serves me correctly, the Enertech 1800 control box needs to see ~10 mph winds for a minute or so, then it will engage the relay that releases the brake and powers the prop up to speed. If the wind speed goes over 40 mph or drops below 7 mph, the control cuts the power and sets the brake. I believe the 1800 relies completely on the mechanical brake, no resistive load... but I could be wrong, I've only flipped through the manual and seen the machine once.
Here's a couple of pictures of the control box, maybe you can glean something from them...






-Norm.

jondecker76:
From your description, the control system sounds spot on to how these larger units operated (Except for different values for windspeed). The control system has its merits (mainly that because it is spooled up from the grid, it will be perfectly in phase as it crosses the alternators synchronous speed, and therefore have very minimal THD on the line). However, in practice for us, it has been horribly inefficient - and since it does not monitor alternator RPM, it has to err on the safe side and kick offline way earlier than it needs to - based purely on assumptions gleamed from the windspeed.
The other thing I notice different is that these larger units use a slightly different control board, has an SCR bank, and uses an EnerPro SCR firing board (which is actually a modified AC motor control board - as I spend quite some time on the phone with Enerpro engineers pouring over schematics to re-enable the soft start feature of the original AC motor controller)
We are putting this unit on another 40KW Enertech this week near Erie PA, then on 2 60KW Enertech machines the week after, also near Erie, PA.

StorminN:
Hi Jon,
I just consulted the Enertech manual...
"The control system is factory pre-set to operate in response to the following 30-second average windspeed data when run in the AUTOMATIC mode.
Over 11 mph - Start-up

Under 8 mph - Shut-down

Over 40 mph - Shut-down ("cut-out")

Under 30 mph - Start-up ("reset")
The control system can also be run in a TEST mode, which has the effect of by-passing the start-up and shut-down controls, and permits the owner to run the windplant even when winds are below start-up speed."
I also looked it up... the gearbox is 11.4:1

There's an electrically-released, triple-disc spring-loaded brake located between the gearbox and the generator. On the far end of the generator (the nose), there's a small box with an emergency overspeed switch inside. It's a centrifugal switch, if the generator overspeeds, this switch interrupts the electrical circuit to the brake and stops (hopefully) the turbine.
So I don't think there's any electronic braking that happens with this smaller control box, just the mechanical disc braking?... but it would be very cool to see how much more efficient a freewheeling turbine is as opposed to one that's braked too often and then powered back up. Do you have any figures as far as efficiency gain? With two identical turbines close to each other like you have in your picture, you might have gotten some numbers?
Thanks,

-N.

jondecker76:
I wish I had the foresight to do such a comparison, but the thought didn't even cross my mind. Early indications are that it is much more efficient (my guess at this moment would be around 25%) and the owner of the twin 40KW machines seems to agree after having these online for about a month now.
I will see if I can talk the owner of the twin 60KWs into letting me do this type of test for a month or so (his towers are almost up now, so they should be flying this month)
11.4:1 gearbox... Yours will be much quieter than these with the 30:1 gearing... The 40KW and above units are quite loud!
I would also be interested in hearing how the local power company deals with you in getting this set up..  We had problems with everything from distortion, failsafes and power factor (where they finally agreed to provide the capacitor banks for us)

Navigation

[0] Message Index

[#] Next page

[*] Previous page