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Old 08-21-14, 08:28 PM   #5
ICanHas
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Quote:
Originally Posted by jeff5may View Post
So could I rob power from the grid by leeching off the harmonics and rejecting the fundamental frequency?
That's exactly how devices cause problems on the grid.

If you were going to apply brakes on your bicycle you can:

apply smooth and steady braking throughout the rotation.... "clean load"
applying 1 x brake pad force over the entire 75 inch circumference of the rim

or you could apply "dirty load" much harder in very short bursts and only when the wheels are in 12 and 6 o c'lock positions.
10 times the force applied to 3.75 inch section at a time, twice per rotation.

This is how dirty power computers draw power.

Even if you do it so that braking effect per rotation (the same amount of power dissipated per rotation) is the same, the latter is a lot more troublesome.

Quote:
If I could catch that reflected power, I don't think the power utility would mind. I don't think they would come looking for me.
The brakes are not "producing power" but you can see that there will be vibration that is in multiples of rotation of the wheel. Given the same braking load, the same will have a lot more effect on a bicycle(say subdivision transformer) than on a truck (a 1000kVA transformer feeding a factory).

The modern issue with dirty power drawing inverter drives(VFD) and power electronics is the proliferation of dirty load relative to smooth and steady load. Power factor corrected devices avoid these issues, but China factories and OEM are opposed to it because of cost.

Last edited by ICanHas; 08-22-14 at 06:41 AM.. Reason: repharase since someone got confused to what I meant by inverter.
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