Homebrew Generator

A homemade generator made from an induction motor, capacitor bank, and 6.5hp engine

Category:

Howto & Style

Tags:

• generator
• electricity
• homeade

[Circlotron]

You may find this paper interesting, particularly the part "series-parallel compensation".

Google for "investigation of self excited induction generators". Can't put the URL here because it brings up an error message.

[Fox22]

Thanks! - btw, you can post a URL but use the format - name(dot)com

[Fox22]

Starting caps are only good to run for a few seconds at a time. I beieve we used 6 47uF caps running in parallel for this one. It is possible to get much more power out of a 2hp induction motor, but the voltage drops as you approach its max output, so you would need a mechanism to add more capacitance as the load peaks.

[Fox22]

The CAPs are running caps usually used to correct power factor on things like motors, power supplies and ballasts. These particular ones came from a ballast for a large HID lighting fixture. You have to make sure that you use RUNNING capacitors, not starting caps.

[dbrannon79]

I like your construction for the engine and the motor! have you had any overheating problems with the generator? the one I built will shut down in about 30 min with just powering a simple box fan! any ideas?

[pusswhakker]

Motorcycle engine actually. And yes I will have to find a way to keep the RPM steady. Thanks for the info.

[Fox22]

Since induction motors are synchronous motors, their RPM is dependent on their input frequency - 60Hz input means 3600RPM output. All you have to do is spin the motor at 3600RPM and you get your 60Hz. Fortunately, smaller industrial engines (lawnmower engines etc) have a governor built into them to keep them at 3600RPM (full throttle) regardless of the load. I am assuming you're using a car engine, so you'll have to find a governor for it so that the RPM doesnt drop as you load the generator.

[pusswhakker]

I am getting ready to build a much larger version. How do you insure that you get the 60hz?  I unfortunately have a high rpm 3 phase induction motor and will have to spin it at 3600 rpm to get it to generate power. Good thing my drive engine red lines at 8 grand :)

[uoitoffroad]

They are just hooked in parallel accross the two poles you are using.

[mladenkorotaj]

how did you connect capacitors,i have 3 phase motor and 3 capacitors,50 microfarad each,on the motor is 6 wires,can youhelp me how to connect,great videos you have,nice job

[Circlotron]

I know exactly what an induction generator is. Good man! Did you realize that you can get the effect of an adjustable capacitor by connecting a capacitor to the output side of a variac and running the input side of the variac to where the variable capacitance is needed? I'm surprised that your setup had no load-dependent voltage drop. Of course, a lagging load like an induction motor would give it something to think about :-)