Talk:Electrical system of the International Space Station

Capacity

What is the capacity of the electrical system on the ISS? LorenzoB (talk) 16:57, 17 December 2007 (UTC)

SSPTS Merge

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result was merge into Political and financial aspects of the ISS. Colds7ream (talk) 11:29, 2 April 2009 (UTC)

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I'd like to propose that Station-to-Shuttle Power Transfer System be merged into this article - it's a fairly short article, with the relevant section here consisting of only a few lines (and so needing improving) - I think that the SSPTS is a fairly narrow topic for an article, and would be better suited in this larger article. Colds7ream (talk) 19:40, 30 March 2009 (UTC)

• Support. The [orginal] version of the article was a redirect here. It's been over a year since an attempt was made to flush out a new article, and the result is still rated as a "stub". For now, at least, consolidating the text here makes the most sense. (sdsds - talk) 20:59, 31 March 2009 (UTC)
• I have no objections to such a merge. --TheDJ (talk • contribs) 22:50, 31 March 2009 (UTC)

Having heard no dissenting voices, I've executed the merge. Colds7ream (talk) 11:29, 2 April 2009 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Weird - what's this got to do with Political and financial aspects of the ISS mentioned in the header above ? - Rod57 (talk) 13:17, 24 November 2019 (UTC)

Why is electrical system on the ISS Direct Current?

Why did the engineering and designer of the International Space Station elect to use Direct Current (DC) rather than Alternating Current (AC) systems?

T. Bert Rose —Preceding unsigned comment added by 76.9.40.176 (talk) 14:33, 10 April 2009 (UTC)

If you read the articles on alternating current and direct current, as well as War of Currents, the answer will present itself, but a short summary:

1. The ISS is an "isolated system" it can use whatever it sees is most useful
2. solar cells that generate energy on the ISS produce DC power
3. The ISS requires batteries to store the solar power and batteries use DC power
4. low voltage DC is much "safer" for humans than high voltage AC. (touching a penlite battery is safe, but touching the wall socket is not :D )
5. Most equipment (computers etc) runs on 12 or 24V DC. (that's why you need transformers for almost ALL your household equipment). Transformers generate heat, so having many transformers is in all the racks of equipment aboard the ISS is "unhandy". So instead only use transformers on the FEW locations that require high voltage or AC power on ISS.
6. The primary reason we use AC on Earth, is because it makes transporting energy over long distance much more energy efficient (even with all the transformators). However the ISS is only the size of a soccer field. That's not so long a distance to cover for the energy.

Hope this helps. --TheDJ (talk • contribs) 15:54, 10 April 2009 (UTC)

We should probably work this into the article... :-) Colds7ream (talk) 16:10, 10 April 2009 (UTC)

As a late comment..

1. "Low voltage dc is safer than high voltage AC" - that doesn't seem very relevant. Why would low voltage dc be the alternative of high voltage AC? Also, as far as I've read you can actually say the reverse: dangerous voltage for AC is less than for DC. (Though way back when AC was introduced against DC, it was deemed more safe, no static charge-ups etc.)
2. Being an isolated : You could have a small island country and call it isolated and still use AC... and on the other hand, you could make a whole building work on DC in a country run on AC. (Actually there have been times in mid-20th century afaik when half the city was AC and other half still DC where I live). Of course it's true that if you are in a place which has available AC then it's generally wise to use it.
3. Your reference on 12 or 24DC has the problem that, according to the article the electric system runs around 124 volts. So there must be a lot of switched-mode power supplies all around. (General observation: higher voltages lead to less loss in the long wires.)
4. Which comes to the final observation. The voltage of solar cells and batteries alike are not directly connected to the energy system but through circuits (switched mode supplies) that actually generate high frequency AC from the incoming DC before converting it back to lower voltage DC. As such the input being AC or DC doesn't matter much (see eg your PC supply which has AC input with a rectifier then a chopper).

My note on this: the possibly higher losses of DC transmission are not significant here. There are not many machines probably that need high voltage AC, such as big AC motors or when there are, they will need variable input anyway, that'll be generated by complex circuitry from DC input as easily as from AC. DC will not create alternating EM field which could cause problems to instruments. (Though the switched mode supplies will generate even higher frequency interference, which will have to be very carefully filtered and shielded.) Creating a nice sinusoidal AC output from DC inputs is not an easy thing (compared to generating it with rotating generators on earth). Hoemaco (talk) 09:57, 15 April 2021 (UTC)

"the article the electric system runs around 124 volts" With the exception of the russian side. The entire Russian side is 28V and the space shuttle also used to run 28V, as do many visiting vehicles (I assume the ones using the PMA adapters). Also it seems that some of the payload racks downstep from 120V to 28VDC. 24/28V is apparently a very common aircraft standard and also what MIR and SS used, so I guess it makes sense. This document seems to confirm that US-side the thinkpads use 120Vdc, and Russian side they use 28Vdc. I wonder if the adapters are multivoltage.... —TheDJ (talk • contribs) 12:25, 15 April 2021 (UTC)

Array mass

I wonder if the mass of the US ISS power system can be put into this article? I am thinking of it as a good reference benchmark for satellite solar power PV arrays, and also for ion drive systems. To be most useful, it would be good to have the array mass, power, and area, and the power conversion system mass, broken out separately. There may be a better WP article giving this kind of information on the current state-of-the-art for space PV power systems; anybody know of it? Perhaps we should make one, if one does not exist. Thanks, anyhow. Wwheaton (talk) 22:54, 12 March 2011 (UTC)

I second that. That would be really helpfull information. Can someone add this information to the article? --46.5.95.121 (talk) 00:58, 8 February 2018 (UTC)

balance - US segment only ?

the article speaks only of the United states orbital segment's power supply. Zip about the rest. Penyulap _talk 12:22, 14 September 2011 (UTC)

Moved article, great solution, as no further work whatsoever is required from anyone. Sweet. Next. Penyulap _talk 10:11, 24 October 2011 (UTC)

The new title is absolutely ridiculous length-wise - I'm sure a shorter solution can be found... SalopianJames - previously Colds7ream (talk) 19:31, 3 January 2012 (UTC)

Furthermore, renaming an article due to bias is not a solution to the problem; dealing with the bias is. I'm going to undo your unilateral pagemove. SalopianJames - previously Colds7ream (talk) 09:30, 4 January 2012 (UTC)

I am puzzled by the note that this article "deals primarily with the United States and do not represent a worldwide view of the subject." The subsection "Station to shuttle power transfer system" could be seen as US-centered, but that section was relocated here from another article. In what way does the rest of the article "deal primarily with the United States"? I would say the opposite; the article seems to have been stripped of references to the US, even when such references would be appropriate. Geoffrey.landis (talk) 13:41, 9 May 2012 (UTC)

I think the whole article issue somewhat comical. Take a look at the ISS article where I've put in something of a move balanced view, and then return here, it's comical that there is simply no mention of anything other than NASA gear. How was the whole station supposed to have stayed up for the first what was it, two years ? without electrical power before P6 arrived, OMG. Thing is, this is nothing new, nothing that hasn't already been explained, nothing that is some kind of secret. Actually, for the full effect, see the Integrated Truss Structure

The International Space Station's main source of energy is from three of the four large U.S.-made photovoltaic arrays currently on the station, sometimes referred to as the Solar Array Wings (SAW). The first pair of arrays are attached to the P6 truss segment, which was launched and installed on top of Z1 in late 2000 during STS-97.

Yep, NASA hype copied right here on Wikipedia. Penyulap ☏ 01:46, 14 Jul 2012 (UTC)

Does the article (and diagram) cover only the US segment, or also the Russian segment of the ISS ? - Rod57 (talk) 13:28, 24 November 2019 (UTC)

How are loads managed

Given that the available power varies from 100 kW (in sun, and charging batteries) to 20 kW (running on batteries), how do the utility loads and experiments vary their consumption to best use the peak power when in sunlight ? - Rod57 (talk) 13:14, 24 November 2019 (UTC)

Potential relative to surrounding plasma

International Space Station says "The station's large solar panels generate a high potential voltage difference between the station and the ionosphere. This could cause arcing through insulating surfaces and sputtering of conductive surfaces as ions are accelerated by the spacecraft plasma sheath. To mitigate this, plasma contactor units (PCU)s create current paths between the station and the ambient plasma field.[197]" (with a ref that doesn't seem to work)
but this issue is not mentioned at all here. - Rod57 (talk) 10:07, 8 June 2021 (UTC)

Battery replacement

Okay, new NiH2 batteries were brought to the ISS to replace old ones. And what happened to the old ones? Went over the rainbow bridge? No second life, not enough space? Jettisoned into the Spacecraft cemetery? Space toilet? Waste management of the International Space Station?  Matthead  Discuß   15:45, 3 July 2021 (UTC)