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| Single phase to three phase sinewave converter |
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| T3sl4co1l:
--- Quote from: CatalinaWOW on January 14, 2019, 07:37:29 pm ---Difference in detail. Single phase distribution exists for local areas (like where I live currently), but unless you are really rural the distance to a 3 phase source is much less than 5 miles. In my case it is about a half mile (one kilometer) to 3 phase power. It still is not economical to bring that in. Hence the market for VFD and other converter technologies. I am sure that it is hard to generalize about this to entire regions or countries. Lucky for you that you live where 3 phase is available. Who knows whether the money spent on that has held back your economy in other ways? --- End quote --- It's my understanding, even if you have a 3ph drop nearby -- say you're neighboring a commercial property that has it -- they still want $10k's to come out and install new hardware, and that's assuming it's allowable at all for, say, zoning reasons? (which I have no idea if that's a thing, but maybe it's part of why). So yeah, 3ph is really rare in the US. Evidently it's rare in Spain too; I've only ever heard it's standard in the rest of Europe, as Yansi has said. I've not visited and inspected their breaker panels myself, I've only seen pictures of them. I don't doubt the veracity of everyone who lives there and says it is in fact available. :) Tim |
| T3sl4co1l:
--- Quote from: sanwal209 on January 14, 2019, 10:36:19 pm ---I simulated in Tina, Have a look at the attached schematics and Waveforms. --- End quote --- Looks nice. :) I don't suppose you can take a close look at the control and see what it's sensing? If it doesn't matter what frequency or phase each of the inputs is, you don't need a phase shifter at all, just wire them up straightaways! Tim |
| Yansi:
I would not consider this solution. it is: 1) fixed frequency only 2) you need a lot of precision parts, or trimming respectively, to reach satisfactory level of phase balance. Don't forget precision foil caps are rare, and a typical resistor is 5 or 1%. I think the solution with OTA providing correct phase at all frequencies without the need for tuning the phasing networks, is better. More bang for the buck. My solution just needs the caps to be the same value. It is likely easier to find three caps of the same value, than to find and select some specific value (or to trim the resistors in circuit). You would need to align both allpass filter branches to obtain correct phase and amplitudes. The three phasing RC 3x 60 degree are self-aligned, always at 60 degree each to make the 180 degree shift to start oscillation. Or have I missed st.? |
| IanB:
--- Quote from: T3sl4co1l on January 14, 2019, 10:42:29 pm ---It's my understanding, even if you have a 3ph drop nearby -- say you're neighboring a commercial property that has it -- they still want $10k's to come out and install new hardware, and that's assuming it's allowable at all for, say, zoning reasons? (which I have no idea if that's a thing, but maybe it's part of why). So yeah, 3ph is really rare in the US. Evidently it's rare in Spain too; I've only ever heard it's standard in the rest of Europe, as Yansi has said. I've not visited and inspected their breaker panels myself, I've only seen pictures of them. I don't doubt the veracity of everyone who lives there and says it is in fact available. :) --- End quote --- In the UK there is also a question of danger. Three phase 415 V is considered to be somewhat more dangerous than the normal 240 V single phase supply. You tend to see signs like this wherever 415 V is present inside a panel: This is (probably) not something believed to be compatible with a normal home. |
| Yansi:
That is the leg-to-leg (phase-to-phase) voltage. We have 400V leg-to-leg, and 230V (any)leg-to ground. Nothing special really, for any extra warnings to be present. (so for the British 240V, a 415 is the correct leg-to-leg voltage). That is just normal voltages one has to expect, when poking his fingers in switchboards. The load from the house is split equally (at least in theory) across the three phases, as each phase-to-ground voltage is the standard 230V (+-10%). Only the large power hungry appliances work with all three phases, to be able to see the phase-to-phase voltage. (There are also exceptions, some appliances use just single 400V input and are connected in between two phases, typically some industrial power supply modules and for example some welders use 400V single phase input - although typiccaly having a three phase plug, but only two phases used as a single 400V). |
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