Author Topic: Tip up 100' lattice ???  (Read 1159 times)

0 Members and 1 Guest are viewing this topic.

Henry Swayze

  • Newbie
  • *
  • Posts: 17
Tip up 100' lattice ???
« on: February 22, 2006, 05:18:08 AM »
I am thinking of looking for a used lattice tower and using it as a tilt-up.  I have a heavy duty winch on my utility line truck but am not sure what headaches or price bottlenecks I am going to encounter by going this route.  The machine will have an induction motor on it to produce synchronies power for net metering.  As a result it will not be light.

« Last Edit: February 22, 2006, 05:18:08 AM by (unknown) »

Nando

  • Hero Member
  • *****
  • Posts: 1058
Re: Tip up 100' lattice ???
« Reply #1 on: February 22, 2006, 08:23:20 AM »
Henry:


Warning: How are you going to produce "Synchronous Power for Net Metering"


How much power are you planning to generate and what is the mill blade length ?.


Net Metering using generators producing direct AC without power conversion is one process that no body has been able to develop in a practical way.


Direct Synchronized frequency to the grid using a wind mill, can only be done if the magnetic field of the generator is synchronized to the Grid frequency and independent of the wind mill "power generation rotating process ".


In the early 1970's there were try outs to do such effort, to rotate the magnetic field independent of the generator rotation, the effort lasted around 5 or 7 years after several massive generators "implosions" when a failure occurred in the equipment to produce the magnetic rotation.


So my interest to know how you are doing such effort.


Nando

« Last Edit: February 22, 2006, 08:23:20 AM by Nando »

vawtman

  • Hero Member
  • *****
  • Posts: 1425
Re: Tip up 100' lattice ???
« Reply #2 on: February 22, 2006, 04:40:42 PM »
Oh Henry.Big dreams start small.
« Last Edit: February 22, 2006, 04:40:42 PM by vawtman »

paradigmdesign

  • Full Member
  • ***
  • Posts: 249
Re: Tip up 100' lattice ???
« Reply #3 on: February 23, 2006, 10:32:32 AM »
well, he could either use a grid tie inverter AC-DC-AC, or he could go with a synchrouns genny maintained at its rated speed through blade pitching, genny resistance.
« Last Edit: February 23, 2006, 10:32:32 AM by paradigmdesign »

paradigmdesign

  • Full Member
  • ***
  • Posts: 249
Re: Tip up 100' lattice ???
« Reply #4 on: February 23, 2006, 10:35:21 AM »
I don't know if that kind of winch would be strong enough, or that your truck would weigh enough.  I think a tower that size could easially weigh 10,000lb.
« Last Edit: February 23, 2006, 10:35:21 AM by paradigmdesign »

wpowokal

  • Hero Member
  • *****
  • Posts: 1271
  • Country: au
  • Far North Queensland (FNQ) Australia
Re: Tip up 100' lattice ???
« Reply #5 on: February 24, 2006, 11:14:20 PM »
First question has to be what kind of lattice tower?


allan down under

« Last Edit: February 24, 2006, 11:14:20 PM by wpowokal »
A gentleman is man who can disagree without being disagreeable.

Henry Swayze

  • Newbie
  • *
  • Posts: 17
Re: Tip up 100' lattice ???
« Reply #6 on: February 26, 2006, 09:14:08 PM »
Nando

Sorry to be slow coming back.  I was out of commission for 3 days with the flu.

I was considering this tower for the Breezy 5.5 KW kit unite with 18-19' blades http://www.prairieturbines.com/  This system uses a 3 phase induction motor as a single phase generator with electronic circuits to regulate speed and power out put.  I do not yet have any personal experience with the system but have generated 3 phase out of single phase using a 3 phase idler-generator motor.
« Last Edit: February 26, 2006, 09:14:08 PM by Henry Swayze »

Henry Swayze

  • Newbie
  • *
  • Posts: 17
Re: Tip up 100' lattice ???
« Reply #7 on: February 26, 2006, 09:43:13 PM »
VARTman

Thanks for the input.  I will try to bite things off in small chunks.  Your work with verticals http://www.windstuffnow.com/main/vawt.htm is impressive and I started there but got side lined by what looked like a practical grid tie system. I could land up back at a vertical.  I have as my highest priority to use and give others a way of economically generating for net metering. Have you looked at the http://www.windharvest.com/windstar/windstar1400detail.jpg commercial verticals?
« Last Edit: February 26, 2006, 09:43:13 PM by Henry Swayze »

Henry Swayze

  • Newbie
  • *
  • Posts: 17
Re: Tip up 100' lattice ???
« Reply #8 on: February 26, 2006, 09:56:38 PM »
paradigmdesign,

I see that Bergey puts its 10KW units on 45g solid rod lattice and since the 7.5 hp gear head motor that Breeze uses is heavy and turning fast generating extra yaw forces I thought I would have to go that heavy.   I was going to try to find an old tower so it might land up being even heavier... 55g or 65g.  The line truck is 2 1/2 ton and winch bed winch has 3/4 cable.  Not sure I would want to push it.  It is old.

« Last Edit: February 26, 2006, 09:56:38 PM by Henry Swayze »

Nando

  • Hero Member
  • *****
  • Posts: 1058
Re: Tip up 100' lattice ???
« Reply #9 on: February 27, 2006, 06:15:33 PM »
Henry:


Beware of such wind mill.


It is an Induction motor connected to the grid for just a few seconds at the time, just when both grid and motor are close to each other.


It does not have a wide range RPM locking to the grid frequency.


To be able to lock the generator, one needs to have the RPM very stable and close to the Grid frequency which it is quite difficult to do with a wind mill either with Furling or Pitch control.


This is the basic reason for the Grid tied wind mills to have an interface between the generator and the GRID and it is called an INVERTER Grid tied.


This inverter allows the wind mill to vary its RPM and power but the inverter within its capability sets the output current just enough to follow the power available in the wind mill -- which for many it is called MPPT ( Maximum Power Point Tracking)


The Breezy needs to have an intelligence with the capabilities of the inverter with MPPT and it is not SEEN or indicated or sold.


BEWARE and ask questions:like generator locking time, how is performed, how is kept and when is lost versus RPM ranges.


My 0.002 dollars worth.


Nando

« Last Edit: February 27, 2006, 06:15:33 PM by Nando »

vawtman

  • Hero Member
  • *****
  • Posts: 1425
Re: Tip up 100' lattice ???
« Reply #10 on: February 27, 2006, 06:57:58 PM »
Very well said Nando.People seem to think and me also a couple months ago that this induction generator idea would be the cats meow and then got to thinking when the turbine got to the desired speed it would soon dropout with fixed blades.My .ooo1$ worth.And lots of wasted power.
« Last Edit: February 27, 2006, 06:57:58 PM by vawtman »

Henry Swayze

  • Newbie
  • *
  • Posts: 17
Re: Tip up 100' lattice ???
« Reply #11 on: February 28, 2006, 12:44:49 AM »
Nando

I will ask questions.  Did you look at their site?  The way I saw it they are putting a chopper on the gen shaft and using the speed as input to a control circuit that is regulating the excitement of the windings so as to maximize power out while working at a fixed RPM.  Do you think I have that part right?

« Last Edit: February 28, 2006, 12:44:49 AM by Henry Swayze »

Nando

  • Hero Member
  • *****
  • Posts: 1058
Re: Tip up 100' lattice ???
« Reply #12 on: February 28, 2006, 08:07:51 AM »
I did, several times.


This is why I say ; CAVEAT EMPTOR :


It is a "pulsed" system, connected for a few seconds at the time

High RPM lock to frequency = generate power

Too high RPM apply the brakes = maybe power generated

Too low RPM disconnect and wait for higher RPM = no power generated


This was tried many years ago, discarded soon, I do not know why.


Nando


Taken from their site:


The generator speed must be monitored electronically. We have designed a micro- controller based circuit and written the program that runs in it. It utilizes a hall-effect device attached to the rear of the motor to determine the speed at which the generator is turning. When power is applied to the generator controlling circuits the micro-controller releases the motor brake and looks at pulses coming down from the hall-device. As the wind turbine speeds up and the micro-controller determines that the generator is running at the correct speed it energizes the main relay connecting the generator windings to the power lines. If the wind speed decreases the main relay is de-energized and the generator is allowed to turn until the wind speed increases enough to allow the generator to begin producing power again. As a safety feature should the micro-controller determine that the generator is turning faster then our programmed upper speed limit the main relay is de-energized and the motor brake is applied. The controller will hold the circuits in this state until it is manually reset.

« Last Edit: February 28, 2006, 08:07:51 AM by Nando »

wvuengr04

  • Newbie
  • *
  • Posts: 6
Re: Tip up 100' lattice ???
« Reply #13 on: March 27, 2006, 09:06:47 PM »
I've been researching grid tie induction generation for windmills. This is how most of the commercial systems do it. From what can be seen on the web, I think the breezy looks pretty good. Their power numbers are impressive. Wish they had one in service longer than  1 1/2 yrs.


The controller they speak of only connects the motor/generator to the grid when it reaches synchronous speed and sets the brake for over speed conditions. Don't confuse that with sychronizing with the grid. The generator does that all by itself.  


The generator operates on the principle of slip. If the poles rotate at the same rate as the frequency, no power is used or generated. As the poles rotate faster than the line frequency, power is generated. If it rotates slower, then its acts as a motor. This is why you need their controller. (if you didn't mind standing by your turbine all the time, you could watch the wind speed on an anemometer and throw a switch to generate power and do almost as well as their controller)


Since the generator operates with less than 5% slip, it stays at pretty much the same speed regardless of power, so what controls the power output is the characteristics of the blades.  For the PM alternator guys, I think output and rotor speed and wind speed are pretty much proportional. That's not the case with the induction setup. The speed is prett close to constant assuming you have enough wind to freewheel the turbine up to synchronous speed.  (There may be more slip since the third leg is connected via capacitors) The power produced is proportional to the wind speed. As the mill freewheels up to synch, the wind is not putting much power into the blades. The angle of attack for the blades relative to the wind is small. When synch is reached, the generator engages. As the wind speed further increases, the apparent angle of attack increases though the blade speed is almost the same. The power also increases as the angle of attack increases. This angle of attack increases until the blade can't produce any more lift. this is called stall. This is a valid, tested turbine control technique called stall regulation.


All this means that your generator must be geared such that cut in speed is at the bottom of useful power production relative to wind speed. At that point you are limited essentially by the blades ability to accept high angles of attack as far as pulling all the power possible from higher wind speeds.


Now, if the slip was higher or able to be regulated, faster blade speeds would be possible which would allow more power to be captured before the stall angle was reached for the blades. I've been looking at designing my own direct drive induction wind turbine with a wound rotor to allow for variable slip. Not a lot of info this type of coil design out there though.


Howie

« Last Edit: March 27, 2006, 09:06:47 PM by wvuengr04 »