- #1

keith03

- 31

- 0

Hello all,

This is my first forum post and any problems with the post are openly accepted.

I would like a sanity check on my approach to this problem. I have built a permanent magnet three phase AC generator. I need help in properly calculating power values for this. This is for practice, as well as a learning experience. Regardless, it is my first time doing this, and my power knowledge is mostly all related to single phase component apps. Please keep in mind that some of these specs were selected by budget, not optimization.

Specs of gen.

number of poles=12

number of coils=18 (four per phase) air core

wired in Delta

number of turns per coil= 78t of 20AWG enameld wire.

estimated Tesla at coil= .25[T]

Estimated output voltage at 240 rpm =34.128VAC[p] at 134[HZ]

Here is my thought process for the Power:

Voltage is known from Faradays Law(Vm=N*(2pi(p/2))A*Bm): v(t)=34.128sin(841.95t+90)

To find Current: i(t)= 1/L * the integral of v(t).

This is my first forum post and any problems with the post are openly accepted.

I would like a sanity check on my approach to this problem. I have built a permanent magnet three phase AC generator. I need help in properly calculating power values for this. This is for practice, as well as a learning experience. Regardless, it is my first time doing this, and my power knowledge is mostly all related to single phase component apps. Please keep in mind that some of these specs were selected by budget, not optimization.

Specs of gen.

number of poles=12

number of coils=18 (four per phase) air core

wired in Delta

number of turns per coil= 78t of 20AWG enameld wire.

estimated Tesla at coil= .25[T]

Estimated output voltage at 240 rpm =34.128VAC[p] at 134[HZ]

Here is my thought process for the Power:

Voltage is known from Faradays Law(Vm=N*(2pi(p/2))A*Bm): v(t)=34.128sin(841.95t+90)

To find Current: i(t)= 1/L * the integral of v(t).

*I am assuming that L would be total inductance of that phase***Real Power**:[W] P=I^2*R ([R] will be internal resistance of wire*and will be RMS current of one phase.)*

This is my thought process, but I know that things get a little different with the sqrt(3) in three phase Delta systems. Cant I just use the single phase calculations and apply them to the three phase system keeping in mind that:

sqrt(3)*coil current=Line current

R (y) = 3*R(delta)**Complex Power**[VA] S=VI* (polar form) S=(P+jQ) Q=Ssin(theta) P=Scos(theta)*Assuming that V and I are of a single phase.***Reactive Power**[VAR] =jQ**Power Factor**cos(theta)This is my thought process, but I know that things get a little different with the sqrt(3) in three phase Delta systems. Cant I just use the single phase calculations and apply them to the three phase system keeping in mind that:

sqrt(3)*coil current=Line current

R (y) = 3*R(delta)

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