Induction Generator

Did you tried doing the same thing to the other one?

No. Because I don't know that how to connect the capacitor in Star connection.

a) How is the capacitor connected on the delta motor?

b) If all 6 leads are brought out into the terminal box you can connect it star or delta.

Cheers.......Codey

Dear Codemaster pl. refer below link : http://www.who.int/management/InductionGenerators%20forSmallHydroSchemes.pdf in this way i have connected capacitors. C2= 100 mfd, C1= 50 mfd

Dear all,

An Induction motor, nomally running below the syncronous speed, becomes an induction generator if it runs higher than the synchronous speed. No need to change connection and no need to add capacitance.

Regards

Dear rudy.leurs@telenet.be, Thanks for your reply. I could not get the formula, capacitor size = nominal motor current x nominal motor voltage x sinus (angle of cosinus phi) My motor details are as below: 2.2kW/240V in Delta/8.4 A/ p.f.=0.84 capacitor size = 8.4 x 240 x 0.84 = 1693 ????? also I could not get, The total capacity of the capacitors equals to I x U x sqrt (3) equals to U x 2 x ∏ x frequency x U x sqrt (3) Can u please explain me in detail. further, pl. refer below link: http://www.who.int/management/InductionGenerators%20forSmallHydroSchemes.pdf I have connected my induction generator in this way. But still I am confused for capacitor selection.

I have not yet tried any induction motor to generator conversion, but was curious and I am still learning. I realize that a 3 phase induction motor is more eficient, but at the current time I just have a single phase 110 volt motor I would like to experiment with. The motor is a 1/6 hp 60 hz 5.3 amp single phase motor. What size run capacitor would I use for this application and how do you calculate it?

Do not use this motor. It is to small, the wire diameter is to thin. THis means that the internal resistance of the windings is to big. If you use this motor as generator, the voltage drop over these windings will be hugh. This means the voltage variation with load and no-load will be big.

I am sure that an asynchronous motor-alternator the stator windings of which are not connected to a main supply grid will not start producing any voltage when rotated at any speed, because there is not any field excitation.

Maybe if there is a remnant magnetic field, it could be.

If the stator windings were fed, for instance from a battery pack through a converter DC to AC, at a given frequency, the machine will start as a motor and if a mover turns it at a speed higher than the synchronous speed of the converter, the motor will work as a generator. Then the capacitors, duly connected, will improve the Power Factor, when the load demands it.

This is may experience, but I am ready to study any other explanation.

Arturo

When you apply the 50mfd cap to the delta winding, you are adding capacitance to all 3 windings and allowing self excitation to occur.2 of the phases are selfexcited to act together and one is against. In a star connection, one capacitor will only excite one phase if phase/neutral connected, or 2 phases if star/star connected, and in this case, it may be that the excitation of one phase will be working against the excitation applied to the other. I would try using 2 capacitors in phase/neutral connection or phase/phase connection.

Dear Guest, Can u please provide me the drawing of the connection?

I realize that the single phase motor for a generator is not realistic for use, but I was curious to try it. Maybe even for like a science project. Is there an existing formula to calculate the capacitance needed? I am currently trying to get my hands on a 3 phase induction motor to play with, but at the current time the single phase can be just a project to learn more about this stuff. I have also heard different stories about using an automotive alternator to generate 110 volts, that I would also like to try. Most of the stories were not good. I have a GM Delco alternator like 100 or 140 amp or so that I again would like to just experiment with. Any of you guys had and experience with this? I read an article where a guy used one tied the field wire to the output and ran the alternator between 8000 and 10,000 rpm and would produce 110 volts at 15 amps. He also had to do some modification inside maybe with the rectifier or diodes to convert the output from DC to AC. He stated that the bearing would only typically last for 400-600 hours though. He powered this with a 5 hp lawn mower engine. Any thoughts?

What kind of output voltage do most people here shoot for. I am really just interested in 110 volt that would be useful in home during a power outage. Really just to operate couple of lights or maybe even freezer. Some people i gather configure to 220v

Ok i got cut short on last post..sorry! I assume the people using the higher voltage are like in Europe or they are using a step down transformer. Can anyone answer this? I am currently searching for a 3 phase induction motor, but I am trying to learn the

Im trying to learn the math associated with findind the capacitor size I will need for the 110 v output. The example in the post above is great, but I need coaching. I never took calculas or what ever that is. I am eager to learn that equation though!

Ok my mobile internet limits my text field size..sorry! I was also wondering whether delta or wye connection is preffered for that 110 vac output. I would like to use an induction motor as an attachment to my 25 hp riding mower for a small backup power.

Ok I figured out how to do the calculations, but was curious if I want 110 vac output do I use 115 for my voltage and 4 amp calculations, say on a 230/480 v 2/1 amp motor? Half the voltage double the amps. How is the output voltage determined?

Also the example motor spec plate didn,t show the pf, well it showed the pf as 63%. So is that .63 pf? The motor is 230/480v 2/1 amps, 3 phase, pf 63%, 1/2 hp. I know its really small. I,m just trying to learn the calcutions.

Does anyone ever respond to this thread?