# I think this defies the principles of electricity but here goes...

Registered Users Posts: 15
Hi, Im new and have what may be a stupid question...

I am trying to do a research project for myself on the efficiency of certain turbines under different conditions.

The primary experiment will be indoors, using an industrial blower to produce 'winds' at specific velocities.

I am interested in measuring the power output (AC) with different turbines under different conditions. Some experiments would include multiple turbines.

I have various wind turbines (just the turbine units) from some systems which have been given to me. I have no desire to charge batteries or to actually use the power (i.e in a grid tie system) and would like to minimize costs in my experiments.

Is there any way (with wind, not solar) to have the turbine produce power and pass it through various inverter's I have (in order to measure final output as though it were a grid tied system (to measure power loss through the whole system and thus the inverter too) without the need for a battery bank?

While I understand the mathematical ways of working out power output, i wish to test a wide range of possibilities and want the cold hard proof rather than the maybes and roughlys.

Am i attempting to defy the laws of electricity by not having a battery bank and if not, is there a way to get to my desired outcome?

I hope it doesn't sound silly and I hope that I have written this so it is understandable.

Bar001
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• Solar Expert Posts: 5,183 ✭✭✭✭
Re: I think this defies the principles of electricity but here goes...

Can you explain why, other than potential costs, that you do not want to emulate a real life situation, ie a turbine that is connected to a set of batteries?
It is the 'real' situation that test the performance of any turbine rather than a hypothetical situation. agreed it does add other factors which can affect the end result/conclusion.

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• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

Welcome to the forum.

The short answer is "no", because even though there are GT inverters meant to be powered directly from wind turbines (like SMA's Windy Boy) without the grid to connect to the inverter doesn't work.

However, you don't really need it to measure the turbine's output. All you need is a fixed resistance load capable of handling the expected output and the appropriate Volt & Amp meter. Apply Ohm's law and the power formula in the right way and you'll have results at least good enough for comparison purposes.

What you want to do is actually very sensible. So many people wait until they have the turbine at the op of the tower before trying to find out what, if any, power it produces. With the unpredictability of wind this is futile.
Re: I think this defies the principles of electricity but here goes...

Me--I would use a MPPT Charge Controller (perhaps like the MorningStar TS 60 MPPT) and use/write a program to "sweep" (or try auto sweep) to find the Pmp=Imp*Vmp points. And use a battery bank as a load (could be an old battery bank--You just need a reasonable voltage and place for the energy to go (you could add heating elements to burn off excess power too). Or a Midnite Solar Classic MPPT charge controller (they do have support for wind turbines--May need to talk with Midnite about how to program/control their MPPT controller to evaluate the output of a wind turbine).

You could use variable electronic loads too (they make them to test power supplies like this smaller model).

A question though... What is the Wattage your turbines will be expected to produce? A 500 watt turbine may need a 1,500-5,000 watt wind tunnel turbine to get "realistic" power from your DUT (device under test). And, even then, you will have an issue of "ducted" flow around your turbine from the wind tunnel testing (need small model and large wind tunnel to avoid the "walls" and shock waves/ducting effects).

In times past, the common method was to mount the DUT to a truck and run it down a mile or more of straight road for "real world" testing (early days of hang gliders used to test this way out by our local airport in Half Moon Bay).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Hi and thank you very much for your replies.

The primary reason (apart from cost) that I wish to omit the battery bank is that I would like to replicate a system that is grid-tied (i.e without batteries.)

Am I correct in saying that I could simply use a household appliance (matching the load with expected output of course) to function as my 'grid'?
Re: I think this defies the principles of electricity but here goes...

Most (all?) Grid Tied inverter use a MPPT (maximum power point tracking) system to collect power from the solar array/wind turbine/etc...

It is difficult to manual do Pmax stuff (adjusting current*voltage) unless you have a pretty stable setup (say the turbine's alternator being driven by a variable speed motor).

You can drive the Alternator and get the P=I*V vs RPM curves--The program a load bank/electronic load to apply current vs RPM to your "real" DUT setup to gather Wind Speed vs RPM/Optimum Power Output (at least that is one way I could see doing this).

Perhaps somebody here has more experience that I with characterizing a (small?) wind turbine... And they can tell you what the "standard" is today.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 1,571 ✭✭
Re: I think this defies the principles of electricity but here goes...
bar001 wrote: »
The primary reason (apart from cost) that I wish to omit the battery bank is that I would like to replicate a system that is grid-tied (i.e without batteries.)

Am I correct in saying that I could simply use a household appliance (matching the load with expected output of course) to function as my 'grid'?

No, you need the grid itself. But why is this a problem? sounds like you have grid power available where you want to run the experiment. So all you need is a grid connected inverter designed for wind turbines, such as a Ginlong, SMA windy boy, Aurora, Mastervolt windmaster, etc. Then program them for the specific turbine you're testing. The turbine manufacturer should supply you with the MPPT curve for that turbine which you then need to program into the inverter. Connect inverter to grid and start testing.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Hi Everyone,

Sorry for the long delay.

To answer one question: The reason I am looking for a way to mimic the power output of the system as though it were grid tied is that my utility company will not allow me to conduct the research with a system tied to the grid. They will only allow a grid tie if a system is installed by one of their contractors and it cannot be altered in any way by the customer. This is why I am looking at an alternative.

All your comments have been very helpful, however I am still stuck. I am very new to the industry - while I have a lot of 'book smart' about how it all works, i have no practical experience wiring anything up etc.

All I need is at some point in the system to be able to measure the power output of the system at the point where the AC current would be heading to the grid. I need to get around the disturbance caused by different sized battery banks etc. It seems to me like it is nearly impossible which is bad as I believe I have come upon something which would be very interesting.

If anyone has anymore ideas (with simple yet detailed plans as to how to build such a system with part recommendations etc), it would still be greatly appreciated! But I may be stretching too far!

Best,

Bar001
• Solar Expert Posts: 3,741 ✭✭✭✭
Re: I think this defies the principles of electricity but here goes...
bar001 wrote: »
Am I correct in saying that I could simply use a household appliance (matching the load with expected output of course) to function as my 'grid'?

Stephendv gave you the correct answer: No.
But I don't think the reason was explained. Grid tie inverters need the grid not only as a place to dump their power, but they also need the grid to serve as a 60 cycle 'clock' that they can synchronize to. I do believe that some folks have set up their own mini grid, but I am an off grid type and don't know too much about mini grids. Perhaps you could try a search on 'mini grid'.

--vtMaps
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• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Thank you for the information!

I have looked into min-girds and it would seem that it is far out of reach for a project of this size. An interesting concept though.

Would it be possible to build a battery (off grid) system, measure the power output (DC) directly from the turbine before it hits anything else and then mathematically adjust it for loss through inefficiency of inverters etc. and come up with a reliable estimate for what the AC equivalent would be in a grid tied system?
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

If your primary purpose is to test different turbines' output under varying amounts of wind I suggest you:

1). Skip the blower. Drive the turbines directly from a motor. You can equate motor speed to wind speed, even if you use an arbitrary standard, for comparison purposes.

2). Skip the inverter and battery bank. Use a fixed resistance load and measure the turbines' output Voltage and current. You'll develop a chart that will show "Turbine A @ X RPM produces Y Volts and Z Amps, Turbine B @ X RPM produces Y Volts and 1.5 Z Amps" et cetera.

That will give you turbine-to-turbine comparison. After the output is applied to a given GT inverter it will make of it what it can. There won't be much difference between one inverter and another. You can factor the turbine's DC power output by the inverter's efficiency rating and be fairly close to what the AC output will be in a real-world situation.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Thank you very much!

That seems very logical and exactly what would work for my purposes!

Forgive me if i get annoying and show my lack of technical knowledge but could you outline the parts I would need to develop such a system?

I would have the motor/blower, turbine, fixed resistance load (I am looking at DC electronic load boxes - is that in the right area?) and what else? I am familiar with the requirements for a grid tied system but not for a system like this. Each and every component I would need would be very helpful! What would be connected to what?

Sorry for the basic questions.. I am going to do extensive research on the application of a fixed resistance load in this type of system but your knowledge would be indispensable!

Best,

Bar001
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

You're first going to need to know what range of power the turbines are expected to put out. That will dictate what else you need, beginning with how big a motor is needed to turn the turbine and how large a resistance load is needed to take its output. Otherwise it is a matter of appropriate size wire, circuit protection (just in case), and two meters; one for Volts and one for Amps. For best results everything, including the meters, would be "hard wired" so the only changes made would be swapping one turbine for another.

For example:
A 400 Watt turbine is going to require about 1/2 HP to operate at full capacity. Getting a motor you can vary the speed on could be difficult. You might use belt drive and different size pulleys to test at different speeds (like a selection of 4) from light to heavy.
It will have output specs like "22 Amps" and "18 Volts" or such, so the wiring, meters, and resistance load must be able to handle the maximum current and Voltage with a minimum of power loss. One good source of info for the resistance load is whatever the turbine manufacturer recommends for a "dump load" because essentially that is what you'll be doing; sending the output to the dump load instead of battery charging and measuring the Volts & Amps when you do.

It's been a long time since I designed an experiment like this! Is any of this helping?

P.S.: study the important little formuli in my signature line.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Yes! It is helping a great deal!

Ok, while i completely understand the rational for using a motor instead of blowers, I have the blowers already and got them for no cost. So for the initial phase, I will resort to using them. Should that not be satisfactory for my research, I will look at getting a motor on which I can change the speeds should it be necessary to go to that expense.

So, the blower I currently have is a 3/4HP motor. 115V and 7.6Amps. It produces a wind velocity of between 29 and 31MPH or about 13.5m/s.

I have a range of generators, from 600W to 2.5KW. My 'dream system' would be able to handle a load up to about 3KW... i.e I would like to test singular generators (like the 2.5KW) and then also separately like to test maybe 2 or 3 smaller say 600W generators in one experiment. As you say, I will need to research what the manufacturers say about the recommended dump loads for the various turbines but ultimately I would like to have a system that can deal with up to 3kw - that way I can vary my turbines, blowers etc without having to modify the system at all or buy new loads etc. I understand that if the system is built to carry 3kw and I'm only using say 1 600W generator, then there will be some loss due to the wiring size but that i can deal with as I am looking to maximize output. (This is essentially what you told me with regards to 'hard-wired').

The laws in your signature were one of the first things i noticed on the forum before I began posting and the brought back a flood of information from my high school science class so yes - i keep them in mind at all times.

So, would you have any specific recommendations given the system size i have described above? I need to get the output voltage etc of each turbine, but the ideal would be to have a system capable of taking just about any output combination from turbines 3Kw and under. Wire Size? Circuit protection etc. Any specific meter recommendations - I need to purchase almost everything for this experiment (apart from blowers and turbines) so any recommendations will surely be used! Does that make sense?

While i certainly plan on having a certified electrician wire it all up, I would like to know that I could do it myself and be safe about it!

Your help is indispensable and greatly appreciated!
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

There's quite a difference between a 3kW system and a 600W one. Not just 2400 Watts either. They quite likely operate at different Voltages and currents. At least they should, as upping Voltage is a better way of gaining over-all power than upping current.

That presents a couple of interesting things. For instance, V-drop on the low Voltage system will be greater for a given wire size than for the high Voltage system. Accordingly, you need the specs for all of them so that your wiring is able to handle both the maximum current expected and transmit the low Voltage with a minimum of loss. The "ideal" resistance load won't be the same for the two ends of the spectrum either. It's much easier to set up a rig to compare one 3kW gen with another, or even a 3 with a 2.5 et cetera.

Just as an example:
600 Watt might be 60 Volt, 10 Amp output into a 6 Ohm load. It would need about 1 HP to spin.
3000 Watt might be 120 Volt, 25 Amp output into a 4.8 Ohm load. It would need about 4 HP to spin.

That's only theoretical, but you can see how everything could change between the smallest and largest turbines.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

That all makes perfect sense.

There is a second aspect to my research too which may prove to be a better starting point.

Through a few contacts in the aerospace engineering field, I was going to test some VAWT's for output and then have them work on the turbines themselves to see if they could increase the RPM's of the turbines to be more efficient on the same generator with the same wind speed.

Maybe a better place for me to start would be to go in that direction first before having to make all the complex adjustments to accommodate a wide array of different sized generators.

Two of the generators I have- and the first ones I would like to test (under both aspects of the experiment) are the following (Specification sheet for each)

Both are similarly rated but with drastically different properties if you look at Amps, Ohms etc.

I would be happy to use whichever one we could design an appropriate system around. Which would you recommend? I ask as i believe their drastically different properties would make it difficult to test both on the same system.

If you could point me to which one would be better suited for max output under this experiment, I would like to design a system that can run with that generator and then I will simply use this system to evaluate the second part of my experiment first. Once I have a system up and running under that experiment, I can then go into the details of further changing it to accommodate the other turbines. I hope that makes sense.

The reason I feel that way is that I wish to get at least one part of this experiment under way in as short amount of time as possible. Once I at least have some cold hard facts to go on, I can see if it is worth the time and money to evaluate different generators rather than simply different turbine designs. If that makes sense!

I am eager to get going but for my countless hours of research, I have been unable to get started! You are helping greatly and anything you have is appreciated!
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

VAWT's have a sort of built-in flaw: the turbine blades have to spin back into the air stream that pushes them around. Maybe your aerospace friends will come up around that. Some have tried shielding the return blades, but even that creates a low pressure area that builds turbulence. As such, VAWT's tend to be a lot less efficient mechanically than their horizontal-axis cousins.

The specs on the two you cite are indeed different. I suspect the first one is wrong, as it gives the current as "6 Amps" which at 1800 Watts would be 300 Volts! Probably it's 60 Amps @ 30 Volts. The other says 1500 Watts with 30 Amps which would be 50 Volts. They certainly have quite different power curves.

The first one builds power more quickly, hitting 1500 Watts at about 400 RPM as opposed to the second which gets to 1500 Watts at about 550 RPM. That means the first one is going to need larger blade surface area to pick up more wind in order to get enough mechanical power to provide the electrical power at lower velocity.

What exactly is your end goal here? Are you testing various turbines for educational reasons? Or are you trying to come up with a viable wind powered GT system for your area? If it's the latter, I'd suggest buying an anemometer and recording the wind speeds, gusts, and direction changes where you are. If you haven't got the wind you don't get the power, no matter what turbine you use.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

My reasons are primarily educational. To be able to correlate the manufacturers claims on output vs. controlled test results. The second objective is to see if different types/styles of turbines improve efficiency and also to see if I can improve efficiency through modifications on turbine structure.

I also felt that there was an issue with their numbers and your reason seems correct on what they actually meant.

So, to proceed, lets say I use the 1800W generator... the one which will hit 1500W at 400RPM... Where do I go from there when it comes to purchasing the rest of the components for the system?

I am having trouble finding DC electric load boxes. My search continues but if you know of any manufacturers, that would be great! Also, what other components are required and do you know of any reputable suppliers? I don't want to be spending money on cheaply made Chinese junk! What type of wiring would be required to carry the load?

Bar001
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

Well there's always NAWS' wind section: http://www.solar-electric.com/wind.html

And while I'm tossing links out: http://www.wind-works.org/articles/small_turbines.html

One of the best wind power sites: http://www.otherpower.com/

And of course Hugh Piggott's page: http://www.scoraigwind.com/

• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Thank you very much for all the links.

I have skimmed them - some i've read before - and will go in further detail a little later on.

It would seem though that I am way out of my depth.

In order for me to get this project going, I would need step by step instructions and diagrams of the system I am trying to build and it would seem that - as this is obviously not a common build - that what I need it not available online or anywhere else.

I am worried that I am going to go to the expense of purchasing all the necessary items (even this im unsure of as I do not know every item I would need!) and then probably not be able to work it correctly. If only it was as simple as connecting the generator to the load box and taking measurements!
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

A college education takes years and costs money. You are literally looking to acquire a huge amount of engineering knowledge. It doesn't come fast, easy, or cheap. Wind turbines involve at least three separate areas of engineering expertise: aerodynamics, mechanical, and electrical.

If you had a more specific end in mind it would be easier for you to determine what exactly you do need and how to go about getting it. As it is you're looking for something that doesn't exist and would need a lot of flexibility in design to accommodate the wide variety of parameters. Even among off-the-shelf equipment some amount of imaginative innovation is necessary to get the system working.

Me, I just get solar electric systems to work. That's why I have all those toolboxes full of various sized hammers. Nothing like threatening to pound things into a flattened heap of scrap metal to intimidate it into functioning!
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

I am not ready to give up on this yet.

Why is it not as simply as connecting the turbine to an amp and volt meter and connecting that to a diversion dump load resistor? Am i missing a critical step that is going to make it not give me the correct readings for the output of the turbine? I am looking at these resistors: http://www.mwands.com/index.php?main_page=index&cPath=36

All I need to know is the Amps and Volts produced by the turbines... thus the Watts. The resistor would be where there energy went and I wouldnt be running this for any long period of time. Am i completely missing the point here or is this a solution which would allow me to conduct the experiment?
Re: I think this defies the principles of electricity but here goes...

Just remember that it is not unusual to require 2x or more from the driving motor to account for mechanical and drive train losses (400 watts out; ~800 watts in).

If you use a gasoline engine as the driving source, you may need even more (i.e., >2x HP to HP ratings).

You might try contacting Midnite solar directly. Their Classic Charge Controller also has a MPPT mode for wind turbines--You might try sweet talking some information (or even a controller+special firmware) to allow you to better characterize your turbine.

The base controller is ~\$600 (more with high voltage options, and even more if you get the integrated load bank)... If this is more than a "one off" type system--It may be worth working with Midnite to see what can be done (or even if they have somebody that can characterize your turbines).

But--Driving a turbine alternator with a motor is only 1/2 the problem... You do have the whole aerodynamic side of the equation too (as Marc/Cariboocoot says). As well as putting the turbine on top of a 60+ foot tower (to get clean air--higher if you have obstructions in the area).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Re: I think this defies the principles of electricity but here goes...

Using load banks is either a pain (manual switching of resistors/carbon piles) or expensive (digital load banks)...

You might try looking for a local college/university with an electrical engineering department. Might get an interested professor and group of students to do the work.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...
bar001 wrote: »
I am not ready to give up on this yet.

Why is it not as simply as connecting the turbine to an amp and volt meter and connecting that to a diversion dump load resistor? Am i missing a critical step that is going to make it not give me the correct readings for the output of the turbine? I am looking at these resistors: http://www.mwands.com/index.php?main_page=index&cPath=36

All I need to know is the Amps and Volts produced by the turbines... thus the Watts. The resistor would be where there energy went and I wouldnt be running this for any long period of time. Am i completely missing the point here or is this a solution which would allow me to conduct the experiment?

In essence, it is. In detail it gets more complicated.

You started out saying you wanted to test some turbines side-by-side and that is not so difficult. You do that just as I outlined before. But when the turbines are vastly different in capacity, that has to be taken into account.

Then you started talking about VAWT's and modifying them to make them more efficient. The moment you want to try and re-design something you step into the complex realm of engineering.

The testing can be done just as I said and you've picked up on; power into resistance load, check Volts and Amps. But you do have to be sure that you have enough input power to spin the turbine and that all the electrical wiring/connections/load is capable of taking the expected output. So you have to know the expected output first.

After that, you could take any given turbine and modify its blades to see if you can get more power from the same amount of wind. But without a degree in aerodynamics you'll be mostly guessing at it. Likewise you could try to modify it mechanically to increase efficiency, and again without fully understanding what is going on you'd be guessing at what changes to make. The same goes for the electrical aspect (skipping reference here to a company that sells badly-wired turbines under the false premise that it increases power output, but yes even companies blunder).

So for your purposes you could experiment in two stages: test the turbines you've selected and find the one that's most efficient in "stock" form, then see if you can make that one better.

You will definitely learn from doing this. But know in advance that what you may learn is that you just spent a lot of time, effort, and money and still have nothing practical to show for it. If you're okay with that, get the proposed turbines' specs and marshal on!
• Solar Expert Posts: 3,009 ✭✭✭✭
Re: I think this defies the principles of electricity but here goes...
You will definitely learn from doing this. But know in advance that what you may learn is that you just spent a lot of time, effort, and money and still have nothing practical to show for it. If you're okay with that, get the proposed turbines' specs and marshal on!

My thoughts exactly! I've been around long enough, have learned and done enough things in my life, to know that Cariboocoot is right on the money.
Marshal on and good luck, you're going to need it.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Hi Everyone,

So after a trip out of the country (to a place with not communications network of any sort!) I am back and have a few questions:

I have a 900w (rated output) turbine. I am going to generate a wind speed of 30mph (about 13.5 m/s). I want to measure the output of the turbine at that wind speed DC.

I have a Dummy load resistor rated at 24-32V and 35 Amps. (between 800 and 1000w). I have a digital amp/volt meter unit rated high enough for the potential output of the turbine.

I have some very basic question which I would like answered just to make 100% sure that what i think is correct and that i am doing this safely.

The turbine unit has 3 green wires coming out of it. The Vol/Amp meter has a red, orange, white and black wire coming out of it. and a shunt. The dummy load resistor has the normal two connection points like the meter. I have 2x 4foot pairs of 1AWG cables. They are heavy duty! Its just what I have. I can get smaller if advisable.

If this was you, and above was what you had and you wanted to confirm the output of the turbine just as i've described above, how would you (in detail) go about wiring it up?

Your input is greatly appreciated. If i've missed anything, let me know but the safe wiring is the key here. Thanks
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

First you need more specific information on the turbine. It's 900 Watts, but what sort of Voltage does it put out? If it's 12 Volts nominal, it will output up to 75 Amps. If it is 24 Volt it will be up to 38 Amps. As you can see, either has the potential to burn up your dummy load. This would be bad. In any instance you must have a fuse or circuit breaker on the turbine output to the load so that if the current is exceeded that will go first.

Three green wires coming from the turbine would indicate its output is unrectified 3 phase AC. If it were DC, there would probably be a black, a red, and a green wire. This makes a big difference in what you do for connecting it. If it's 3 phase AC you will need to build a rectifier circuit that can handle the output. That's one "positive" rectifier and one "negative" rectifier coming off each wire and going to common positive and negative bus bar points.

The meter(s?) should have come with instructions. Typically the Voltage connections go between (+) and (-) and the current connections go across the shunt which is wired in series (usually to the negative line).

The only problem with "too large" wire is it can cost money and be difficult to manage. Too small wire is what gets you in trouble electrically. There's no question that 1 AWG can handle the current as it can handle over 100 Amps.

But you do need some more info to get started on the wiring.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

The turbine is a 24v turbine. I do not believe it is going to reach anywhere near capacity so I am willing to risk the current dummy load. If it seems like it is going to get close as i increase the wind velocity, i will shut it down and upgrade the unit.

As far as the circuit breaker/fuse goes, what do you recommend? Is there a way for me to build one?

The turbine that Im using in this experiment is the Gudcraft 900w 24v turbine. I am aware that it is not the most efficient, but it is what I had! The three green wires would, as you say, suggest that it is 3 phase AC. Please explain to me - does this mean that it does not require an inverter? or it has one built in? I didn't buy the turbine and i just assumed that it produced DC.

I already have the 1 AWG cables so cost is not a problem. efficiency maybe.

I would like to be able to set this up myself with your help but if i were to call an electrician, is there anything in particular that I should say? Im sure they wont have had many enquiries like this.

Again, thank you so much for your help.
• Banned Posts: 17,615 ✭✭
Re: I think this defies the principles of electricity but here goes...

There is no practical way to build your own fuse or breaker. Fortunately they are cheap enough to buy. Since the turbine's output is nominally 24 Volts and your dummy load is rated for up to 35 Amps you can use standard automotive type fuses which are readily available. They have a Voltage limit of 32 (maximum they can safely interrupt), but ought to work in this case. I would not go over 30 Amps, just in case. You can always "fine tune" the parameters later. You really only need 10 AWG or 8 AWG to handle this power.

3-phase in an AC system which uses three separate conductors to carry three waveforms 1/3 of a cycle out of phase with each other. Thus you have 'X' Volts from 'A' to 'B', and from 'B' to 'C', and from 'C' to 'A'. This has nothing to do with inverters. It is a common power production method of alternators. The one in your car operates this way, but the AC is converted to DC through rectifiers. I've attached a basic diagram of 3-phase alternator and its rectifier block. Your wind turbine probably has permanent magnets in place of the energized armature windings.

An electrician probably wouldn't be of much help, as this is not the sort of thing they're trained to work with. Most of them don't handle DC circuits at all, much less experimental ones.
• Registered Users Posts: 15
Re: I think this defies the principles of electricity but here goes...

Thank you for your input. It is helping a great deal.

I do have a charge controller which had 3 input points, a 32v fuse and 2 output points. Would that suffice? If so, how do i connect all the components up?

I am also confused when it comes to the volt and amp meter. as i described, it has the 4 wires and the shunt. I am still confused, even after reading the instructions as to how to safely wire it up. What do i do with the ground wire?

Thank You!!!!