wind switch & rectifier loss

[georgeodjungle]

i was thinking on adding a wind switch to my wind gennys.

to bypass the diodes and spueeze a lil more out of them.

ya know to bypass rectifer losses mostly.

i have one made up now that i was going to install when i do my winter preventive maintenance.

i've got a good balance, but on them no wind times and the bank gets a lil low,

and thinking on starting up the old b&s genney.

could give that lilbit more and buy some more time.

do you think it's realy worth it ?

any body else using one?

[adelaide]

hi  u could put little adjustable flap on tail that switches a switch across the diode automaticaly in wind(spring return)i imagine diode would be slightly better up in the wind but make sure u have fuse near battery. This would work with dc motors well like tape drive motor or to excite car altnator but dont see how u can bypas bridj rectafier if is ac wind gen would be some smoke ?

I do a similar concept with solar panels. I use smaller panel through diode to batteries but tap into the solar side to trigger relay to bypass all other solar cells diode (main pannels) automatically and does gain me a few more amps.

Maybe use multi-meter and try to get some feedback?

Aaron

[Nando]

One needs to be clear with the project and, as well, being able to do some calculations to define any change that one may do to a Wind Mill.

The diodes in a 3 phase generator accomplish several things,

One: to couple the phases to a common output point or lead,

Two: To peak the power output

Three:To level the output voltage with low fluctuations.

Four: to reduce the number of wires exiting the Wind Mill to the battery bank or load.

If the removal of the diodes increases the power output in a % that may be high, then there is an indication that the output power is extremely low.

The equivalent power gain is to about 2 volts times the output current, that in a regular systems may represent less than 1 or 2 % of the overall power (may less).

To Obtain greater power output from the same generator, ( from about 46 % at maximum peak power to about 80 to 85 % at the same power point) the loading of the generator needs to be done NOT with a battery clamp charging method but by allowing the generator to increase its RPM and to loading it with a variable power curve using a charge controller that looks and or behaves like a MX60 from Outback.

With this set up, let's say a 1000 watts wind mill instead of giving around 46 % efficiency at peak power, the wind mill may be giving 85 % efficiency or 850 watts out to the battery, instead of 460 watts, and the generator dissipating in its body about 540 watts -- lousy coupling I would say that UNHAPPILY most of the wind mills are set up at the present.

I am attaching a figure of a Chinese generator that is sold in Europe, that shows the % when used in a charging mode with a battery as a Clamp load that if not clamped can increase its output power to about 80 to 85 % -- the right way to load ANY GENERATOR.

Regards

Nando

[georgeodjungle]

yep there dc:

with no spring return ,just gravity will work.

so with 1% or so gain on each one would you do it.

maybe i'll try just one.

[adelaide]

intrested to know if makes better? my gess yes unles ur blades are stalled a bit will let rev bit more to get in their power ban if left in , .6+v more but more than likly will help .i got few amps more when i bypassed diods with relay day swich on sola(free power cos bits liying around),try with diod and multi meter and swich few times and av result out ?

[mkseps]

Here's your controller answer!

Gene

On page 82 in the October issue of Popular Mechanics Magazine, witness this article:

WIND ENERGY CONTROLLER

How It Works:  In a small scale wind turbine, the wind rotates the turbine, which spins the generator, which produces AC voltage.  But because the wind speed is variable, the voltage is also variable and may be too low to be stored in batteries or fed into the grid.  Andy Knight, associate professor at the Department of Electrical and Computer Engineering at the University of Alberta (Canada), leads a team that has come up with a system that enables turbines to harvest voltage in relative calm conditions.

    With the Knight team technology, the AC current produced by the generator is converted to DC in the rectifier so it can be stored in what is generally a 12-volt battery.  Since a battery cannot recharge on a voltage that is lower than its output, the team's unique controller monitors the frequency of the AC from the generator.  If the voltage is too low to be rectified and sent through the system for storage, the controller directs a switch in the converter to stop the flow of electricity and pool it until the total voltage is 12 volts.  The switch in the converter opens and closes about a thousand times per second.  By adjusting the ratio of open to closed time, the device precisely controls the voltage.

Time Frame:  Manufacturers could incorporate the controller now by tweaking existing designs for small scale turbines.

Payoff:  "In a region that's borderline as to whether or not it's worth it to install a turbine" - that is, places where average wind speeds are less than 11 mph or so -"this controller could make all the difference," Knight says.  A study he conducted at the Edmonton International Airport indicate that his team's system could increase a small turbine's energy production by 50 percent over a three-month period.  That means a 6-ft. dia. turbine could produce 24 kilowatt-hours (kwh) a day.  The standard U.S. household uses 35 kwh a day.

What would it take:  The converter and controller, which contain fewer electronic components than comparable devices on large-scale wind farms, are designed to be an inexpensive retrofit for stand-alone turbines.  Add an inverter to change the battery's DC voltage back to AC, and the homeowners could sell surplus electricity to the grid.

Not so fast:  Even a small-scale turbine requires a reasonably clear site so that wind can hit it from any direction.