College Wind Turbine Project

Hey everyone,

I am an Electrical Engineering major freshman currently in college working on a small-model wind turbine along with two other people. This project is basically our only project for the entire semester, the reason being that we're thrown into this project regardless of our current knowledge in engineering. The only thing that me and my group knows so far is the basics on how a turbine works (even then, it's quite a little).

I am in charge of the programming of the wind turbine specifically. We are given an Arduino Uno to do this, and I myself have ordered an Arduino kit so I could learn more about it at home. However, I'm still confused on how to start this whole project up...

  1. How does a wind turbine charge a battery?
    I know that in a typical wind turbine, wind moves the turbine blades which spins an internal generator to convert kinetic motion into electricity, but aside from that, I do not know what process stores it into a battery. What are notable parts in the process and does it apply to a small-sized model of a turbine as well?

  2. Isn't charging batteries dangerous?
    I've read from multiple sites that charging batteries were dangerous and there was a specific type that wasn't as dangerous. If I remember correctly, our projects goal is to be able to recharge a battery. I'm guessing it's a AAA, or maybe a AA. I've also read, however, that with a such a small-scaled power generator, accidentally over-charging batteries won't happen and it wouldn't be dangerous because of that.

  3. What is a dump load? Should I add one to my wind turbine?
    The only thing I've read about it is that it regulates the current being put into the generator by being a dummy for which electricity passes through it. Aside from that, I don't know much.

Please note that my knowledge of electrical engineering is extremely basic; I probably don't even have the basic concepts of voltage and current down (I've tried really hard to understand them, though). Any advice or tips for my group's project or electrical engineering in general are greatly appreciated.

bump

You can learn about battery charging at http://batteryuniversity.com/.

What do you imagine an Arduino would do for your wind turbine?

  1. If the generator voltage exceeds the battery voltage, then current will flow into the battery. This is called "charging".

  2. I'm sure it won't be hard to generate enough power to heat up a AA battery to the point where it explodes. It depends how big the turbine is.

  3. If the turbine has no way of reducing power (moving blades or a mechanical brake) then you may need a dump load. If you can just disconnect the battery and let the generator voltage float up (to hundreds of volts) then you may not need the dump load.

It would help a lot to know what sort of Wind Turbine is being used, what sorts of wind speeds it will be exposed too and what kind of battery is to be charged.

Since I have lived the past 16 plus years off gid, and built both of my wind turbines I might be able to help.

We need to know exactly what type of battery to be charged. Our batteries are flooded lead acid batteries that can withstand a great deal of abuse, but such shortens their effective life. Overcharging these results in excessive outgassing and possible plate warping. Some other types of batteries will fail violently under such abuse.

One can use a permanent magnet motor as an alternator, which is exactly what my wind turbines are. Both are GE electircally commutated (ECM) motors where the rotor has magnets attached, and as the blades via wind energy impart motion the rotor passes the magnetic field through the coils and current flows. This is in the form of alternating current in a “wild” state. The “wild” terms means the intensity and frequency is all over the map. Such is the nature of an inconsistent wind power.

If your battery is a small capacity type your wind turbine must closely match this battery. You will also need to be able to monitor the state of charge and either shunt the input into a diversion load, such as a segment of nichrome resister wire, or short out the turbine to lock the rotor. Also a furling mechanism can protect the turbine itself from extreme wind where the tail pivots to push the blades at an angle to the wind and slow the rotation.

A stepper motor, when spun, will function exactly like my turbines. A modest sized one will easily reach 12 volts DC of rectified output in a decent wind. The recitfier serves to change the alternating current into direct current, which is what all batteries produce and store. These are readily availble and can also be built from four diodes. I have played around with such stepper motors and used the plastic blade from a box fan. A bipolar stepper will need two such rectifiers, or an array of 6 diodes.

One other common form of wind turbine exists, but are highly problematic. These are DC motors that when spun produce DC directly. The problem with these is they all uses brushes which wear both themselves and the commutator. A blocking diode is required to keep the battery power from backfeeding the turbine when it doesn’t spin. I tried one of these and gave up on it because it takes a higher wind speed to get any power in comparison to the PM motors.

Another type of highly complex alternator exists. These are dual disc axial flux permanent magnet alternators, but I suggest these are far outside the scope of your project. Also self excited alternators are out there where power is fed into the rotor to create the magnetic fields, but these are either highly inefficient or massively complex.

Anyway, provide some specifics and I am sure the community can assist. In the mean time you can look at the web site http://www.fieldlines.com/ for more info on wind turbines than you will ever need.

RS

Our professor changed the project to just simply lighting up an LED as wind passes and turns the blades because of the fact charging batteries could be potentially dangerous. However, to everyone who took time to write down their thoughts: thank you.

Our group has created a prototype of our project, but the LED doesn't light up when the turbine blades rotate and the motor shaft turns. We made sure the direction of the spin was correct and we even manually spun the shaft, by which it worked. Is the wind from the fan not strong enough to light up the LED compared to us manually spinning it?

Hi,
Can you post a picture of your project please?

Thanks.. Tom.. :slight_smile:

Gwonnywong:
Our professor changed the project to just simply lighting up an LED as wind passes and turns the blades because of the fact charging batteries could be potentially dangerous. However, to everyone who took time to write down their thoughts: thank you.

Our group has created a prototype of our project, but the LED doesn't light up when the turbine blades rotate and the motor shaft turns. We made sure the direction of the spin was correct and we even manually spun the shaft, by which it worked. Is the wind from the fan not strong enough to light up the LED compared to us manually spinning it?

I built a wind turbine (aka whirleygig) several years ago. I added a LED to the generator (small motor) output and it worked fine until a strong wind generated so much voltage the LED burned out. I needed to liit the voltage going to the LED and put a resistor in series with the LED to limit the current. I never did.

Paul

Hi,

I am working on a very similar project and was wondering if you had any advice how to get started on the coding regarding the sensor / lighting the LED.

Thanks.

Hi,
Welcome to the forum, it might be worthwhile you starting your own threat giving details of your hardware and how you want it to work,

Tom.. :slight_smile: