all units have similar run times of between 35 and 40 percent at 70 degree ambient temp.
what i am in reference to is run capacitors and not start capacitors.
all of my inverters, modified sine or rather modified square wave units will start and run capacitor start and capacitor run motors, without problem.
yes pfc is done to cover the magnetizing component, which in some cases is as much as 60 percent of the total power that has to be delivered to the motor before any useful work is done.
i am aware that the power company doesn't charge me for poor power factor in my home, but rather an average with there meter, (cheaper for them).
but the fact remains that if i am the power company, i still maintain that it is in my best interest to incorporate pfc in my system.
the funny thing is pfc is so poorly understood by so many people,including many so called electrical experts, i have heard everything from...
i maintain that pfc by means of capacitors are far cheaper and easier than additional fuel for a generator, larger windgenerators, larger inverters, larger pv panels, etc. etc.
if it works for industry, it stands to reason it would work for tha standalone power system, albeit the decimal point moves over a bit.
bob g
Assuming your wires are heavy enough that heating them is not a major fraction of your power usage, a bad power factor doesn't make any significant difference in your fuel usage, battery discharge, etc.
What it DOES do is reduce the amount of REAL power you can get out of your generator, inverter, etc.
In the case of a generator, your generator just runs out-of-phase (leading) to make it up. The limit on your generator's output is the current it produces. The power pulled from the motor shaft just provides the real power (which includes the power running your refrigerator, plus the heating of the generator coils and house wiring.)
Similarly with the energy pulled from the raw DC supply inside your inverter. The reactive power pulls energy to magnetize the core of the generator, then PUTS IT BACK into the raw power supply when that part of the core is demagnetized again as the cycle moves on.
Where it might bite you is that you might need a bigger inverter to provide enough current to run the motor. There are losses in the converter's guts that are proportional to its maximum capacity, so a bigger inverter pulls more power just sitting there turned on.
And (as with "copper losses" in a genny) there are also losses that are (non-linearly) related to the current pulled rather than the power pulled (i.e. not all of that magnetizing energy gets back into the raw supply.) So, like the power company, you do lose SOME real energy if you have to "generate" reactive power. Nowhere near as much as if you needed one VA to provide one VAR. But it's not zero either.[ Parent ]
