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Old 08-25-14, 10:11 PM   #29
ICanHas
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Originally Posted by jeff5may View Post
Ok., so when do you think the general public will catch the wave and start building their own homebrew air conditioning system s with dirty vfd driven power supplies?
As I said, even one unit can have adverse effect depending on distribution transformer size.
It is about "eco friendly" so if the energy consumption that is inclusive of transformer loss and reduced reduction in your neighbors' AC motor efficiency overwhelms your point of use energy savings, you failed at reducing energy use.

Quote:
And when will they go back to good old core and coil setups? My guess on both counts is never.
When PoCo starts assessing penalty for harmonics which becomes easier than its ever been as smart meter enjoys greater penetration.

Quote:
Originally Posted by jeff5may View Post

What I want to hear more about is a harmonic eating power cleaning device.
We're already getting our feet wet with this upcoming problems which is why the future is in mandatory integration of such cleaning parts into every harmonic producing equipment much the same way as catalytic converter mandate on cars.

I already linked you to it. The ABB link. Some inverter mini-split A/C units already have a very effective harmonic mitigation built into it. The ABB version and the one built into some modern electronics is the active PFC type.

Here's a passive type:
http://www.artechepq.com/assets/files/SinglePhase.pdf

That type of passive filter was very common for somewhat older IEC spec computer power supplies as well as US spec electronic ballasts. That sort of external mitigation is not needed if it is already taken care of within the device.

ANSI requires THD of <32% for lighting ballasts. This was a requirement created in response to earlier unfiltered ballasts causing problems from excess harmonics. The old design was well before electronic ballast load became a big proportion of commercial building load.

The increased use of non-linear load is headed the same way as they gain share in percentage of load supplied to homes.

Last edited by ICanHas; 08-25-14 at 10:17 PM..
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