4kW PSU in 20cm by 20cm by 8cm? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 29, 2022, 10:40:09 pm
content: Is it possible to do the below PSU in size of 200mm x 200mm x 79mm?4kW offline PSU….100-265VAC input. Output = +/-180VDC.(4kW is constant load, not just peak)Fan cooled, vented enclosure.External ambient to 40degC.

author: uer166
author_rank: Super Contributor
timestamp: May 30, 2022, 12:45:35 am
content: Sure it is, if you know what you're doing and you don't mind it sounding like a server-rooom-ful of supplies.

author: Faringdon
author_rank: Super Contributor
timestamp: May 30, 2022, 01:54:46 am
content: Thanks, you mean we'd need super massive airflow cooling for the size indicated?...because its really too small for 4kW ?

author: janoc
author_rank: Super Contributor
timestamp: May 30, 2022, 09:52:27 am
content: Quote from: Faringdon on May 30, 2022, 01:54:46 amWell, I am not a power engineer, but if you take a ballpark 80% efficiency, that means you need 5kW input for 4kW output. So that little 20x20x8cm box will need to dissipate 1kW of power somehow. Unless you stick it in front of a jet engine exhaust or liquid cool the thing, I just don't see that happening in that volume.Even at 95% efficiency you would still need to dissipate 200W there.You surely know that, right?

author: Faringdon
author_rank: Super Contributor
timestamp: May 30, 2022, 11:16:09 am
content: Thanks, i must confess that on digikey, many PSU's offtheShelf of 4kW and more, are 3 phase input.This one is single phase and 3000W input.....https://www.meanwellusa.com/upload/pdf/CSP-3000/CSP-3000-spec.pdf...its 280mm x 178mm x 65mm = 0.00324m^3The questioned size of 200m x 200mm x 79mm is 0.00316m^3 = 3160cm^3....so its not that far off.this 3kW onehttps://www.xppower.com/portals/0/pdfs/SF_HDL3000-HV.pdf...0.305m^3................................__________________________________............................................Searching [>3999W & Single phase input] takes quite some doing on digikey...but reveals the following 4.9kW PSUhttps://www.artesyn.com/assets/ivs_ds_1591841960.pdf?a=8ae629292cc593d996b2a70d782393c20eb251a2...its 280mm x 203mm x 127mm = 0.00722m^3...but cost unknown to Digikey...just says "Active"......(which presumably means they see what they think you can pay?)...so if volume scales linearly with power...then 4kw and single phase would be 0.00589m^3 = 5890cm^3......186% bigger than the questioned size of 3160cm^3 (just less than twice the size)The Artesyn IVS PSU range seems to be the only 100-265VAC input 4-5kW output PSU on the market._________________________-------------------------______________________________This one is 3phase and 4kWhttps://www.belfuse.com/resources/datasheets/powersolutions/ds-bps-tcp3500-series.pdf...Costs 2300£ and is 0.0035m^3____________________________---------------------------------____________________________________I suspect that at 4kW and single phase, people probably go direct to China?I wonder what the cost would be?.....100/1000/10000 / yr ?

author: Wolfram
author_rank: Frequent Contributor
timestamp: May 30, 2022, 12:35:15 pm
content: The 3210W and 4500W Artesyn supplies are 170 - 264 V inhttps://artesyncom-prod.scdn8.secure.raxcdn.com/assets/trn_ac-dc_ivs_release_1_0_2011558451230_techref.pdfIt's certainly possible to design your proposed converter to fit in in three liters of volume, but it's hard to give any advice without a full set of specifications. Does the output need to be isolated? What output regulation do you need? If it doesn't need isolation, it could be as simple as a single-phase unidirectional APFC set to give 360V, with a synchronous buck running at fixed duty cycle to give you the midpoint reference.If you truly need 4 kW output at 100 V RMS AC input, then the PFC will have to be dimensioned for the full 40+ A mains current, while still handling up to 264 V in. This would make the design more like a 9 kW 230 V PFC in terms of component sizing, if you want to compare your requirements against other reference implementations.

author: Faringdon
author_rank: Super Contributor
timestamp: May 30, 2022, 02:56:52 pm
content: Thanks, yes full output isolation needed (3750AC RMS) and regulation tight aswell.(I like the reference to litres aswell.....a 2 litre bottle of coke, and a 330ml can of coke , is still my "reference object" for getting a sense of volume)QuoteMany thanks indeed for your correction.....that means there are no 100-265VAC , 4kW+ SMPS's available anywhere in the world (off the shelf)

author: dmills
author_rank: Super Contributor
timestamp: May 30, 2022, 03:39:10 pm
content: No real surprise that!50A @ 100V up the snout, that is not a common requirement, and I think a 63A CEE mains connector is a significant fraction of the size of your proposed power converter!Nobody is doing single phase input at that power level if they have any choice at all, and certainly not in universal input.Some of the telecom 'rectifiers' come reasonably close, I have a couple of Eletek flatpack2 units that I use for RF shenanigans that come in at 109 x 41.5 x 327 mm and manage 2kW. You can get these with an output voltage that can be wound up to 170V, so two of them would get you +-170V @ 4kW but while they can operate down to 85V input they derate fairly savagely below about 170V up the snout.

author: coppice
author_rank: Super Contributor
timestamp: May 30, 2022, 03:45:41 pm
content: Quote from: janoc on May 30, 2022, 09:52:27 amAchieving high efficiency in small high power supplies is more about simplifying the heat extraction than reducing energy waste.

author: janoc
author_rank: Super Contributor
timestamp: May 30, 2022, 03:48:35 pm
content: Quote from: coppice on May 30, 2022, 03:45:41 pmWhich is why I was talking about it. But Treez didn't mention what kind of efficiency they are shooting for - and whether 95% is even achievable for what they are doing. Even 200W of heat (+ any derating, margins, etc) in such a small box would make me pretty uncomfortable. So

author: Faringdon
author_rank: Super Contributor
timestamp: May 30, 2022, 03:51:47 pm
content: QuoteThanks very much for that, so thats 4kW from 2960cm^3....but only from 170VAC upwards.QuoteWell yes hopefully 95% at full load...so yes, 200W, at least, to blow away.

author: coppice
author_rank: Super Contributor
timestamp: May 30, 2022, 03:53:18 pm
content: Quote from: janoc on May 30, 2022, 03:48:35 pm95% is almost always achievable.... if you are prepared to spend enough. It can complicate the supply, though, which is in conflict with a tight space requirement.

author: Faringdon
author_rank: Super Contributor
timestamp: May 30, 2022, 03:54:52 pm
content: QuoteThanks, the golden question is , of course, what is the highest power SMPS you can buy offtheshelf that does it from 100-265VAC?I would guess 3680 Watts..thats 115VAC * 32A ?Though i think some SMPS's run off remote mains generators, and they can be more than that....especially if its being used on someone's private property etc.Basically if someone asks for a 4kW single phase input PSU, isolated, regulated output, 100-265VAC input, do you tell them, "no you can't have that....no installation would be available for you to ever plug it in?"

author: Gyro
author_rank: Super Contributor
timestamp: May 30, 2022, 08:38:25 pm
content: Why are you double posting this stuff?https://www.eevblog.com/forum/beginners/how-to-search-on-digikey-for-psus/Is the one in the Beginners section 'treez (and his mates?) doing a hobby project' and this one the 'treez and his mates' prototyping a product (having failed to design one themselves)?

author: Simon
author_rank: Unknown
timestamp: May 30, 2022, 08:58:22 pm
content: Uh, you want a buck-boost? well it's a transformer if you want isolated anyway.4kW output could set you back as much as 5kW input. That exceeds what a single phase socket can supply unless you go 32A which are huge. At that point most people play nice with the grid and make it 3 phase. So you will need active power factor correction, that is 3 stages of boost converter right there. Then you will need to step down. If it were not for the size requirement it would make sense or maybe it does anyway to design 3x 1.5kW single phase converters.This is not a job for the uninitiated of which... I am one.

author: tggzzz
author_rank: Super Contributor
timestamp: May 30, 2022, 09:05:43 pm
content: Quote from: Gyro on May 30, 2022, 08:38:25 pmThe threadhttps://www.eevblog.com/forum/supporters-lounge/treez-how-many-more-accounts-are-acceptable/msg3612350/#msg3612350summarises the issue.Basically, it is what treez, zenerbjt, opampsmoker, coffeefet, Faringdon, does. Like Canter and Siegel, Faringdon has his own style of communication. I wouldn't be surprised to find the same questions on other forums.

author: janoc
author_rank: Super Contributor
timestamp: May 30, 2022, 09:10:08 pm
content: Quote from: coppice on May 30, 2022, 03:53:18 pmEither way that would be 200W to dissipate without any margins, so probably has to be designed for at least 250W or even 300W dissipation. That's going to be pretty tough to cool in such small volume only with a fan and some metal heatsinks. And that assumes that the supply can be actually built in such small space in the first place (and ignoring all the input current issues mentioned already).Sounds like someone promised something to a customer that borderline violates laws of physics here

author: jonpaul
author_rank: Super Contributor
timestamp: May 30, 2022, 09:10:22 pm
content: modern design can achieve 90..95% eff, with GaN or SiC switches, soft switching, low losses Pfe, Pcu in magnetics.Itis neither cheap nor off the shelf.This is what power electronics designers and consultants get paid for.Perhaps our friend from the UK just wanted the work for free? (:-:)Jon

author: Faringdon
author_rank: Super Contributor
timestamp: May 30, 2022, 10:31:51 pm
content: QuoteThanks, please could you possibly advise approximately how much would it cost us to get a consultant to do it? (ball park figure?)(4kW, Single phase 100-265VAC, isolated, regulated, fan cooled, vent holes in enclosure, max 40degC ambient)And also, please advise the cost for the easier spec of ...(4kW, Single phase200-265VAC, isolated, regulated, fan cooled, vent holes in enclosure, max 40degC ambient)?

author: jonpaul
author_rank: Super Contributor
timestamp: May 31, 2022, 06:22:28 am
content: Bonjour cher MonsieurI consulted decades ago 1970s..1990s. My recollection is $300..500/hr, no fixed cost is possible.Nowadays most of the PSU design is in China and consultants are rare and fully booked for years.The customer writes a SOW...Statement of Work, definingsource, load specsenvironnement, temp amb min, maxcooling, airflow, acoustic noiseRegulatory compliance for EMI, power quality and safetytargeted sizes and weightEAU..estimation of yearly usetargeted production costDefine insurance, hold harmless and potential liabilities.A serious OEM firm will be familiar with the use of expert consultants.Check the IEEE power electronics, and industrial applications proceedings for advertisements...lots of positions available but no ads for consultants...Finally depending upon the anticipated production quantity, the costs of design, testing, compliance and set-up are amortized thus a 100k quantity products can afford a 200K$ design but a 10..100 pcs run cannot.Just the ramblings of an old retired EEBon chanceJon

author: Psi
author_rank: Super Contributor
timestamp: May 31, 2022, 06:40:54 am
content: Might be worth flicking your size/spec requirements towww.powerstream.comand checking if they have anything that might work.They are great at customizing their existing designs to meet your needs.And even if it does cost a bit to get something custom, it will still be cheaper than getting something made from scratch. (Unless you're planning on selling 10000+ of them?)

author: tggzzz
author_rank: Super Contributor
timestamp: May 31, 2022, 08:55:27 am
content: Quote from: jonpaul on May 31, 2022, 06:22:28 amThat's the classic "trigger" for FaringdonLet's see how much self-restraint he has now.

author: Gyro
author_rank: Super Contributor
timestamp: May 31, 2022, 09:01:06 am
content: Not any more - he is (or was, you can never tell from day to day) working for them. He regards them as jolly good chaps these days.

author: dmills
author_rank: Super Contributor
timestamp: May 31, 2022, 03:42:16 pm
content: Quote from: tggzzz on May 30, 2022, 09:05:43 pmOuch! Been a while since I heard those names.Still haven't forgiven them for the greencard spam that trailblazed commercial Usenet spamming, and ruined a good thing.Regards, Dan.

author: tggzzz
author_rank: Super Contributor
timestamp: May 31, 2022, 04:49:49 pm
content: Quote from: dmills on May 31, 2022, 03:42:16 pmYes, I well remember that - and also "the year that September never ended"But someone was going to do it; C&S just got there first.

author: Siwastaja
author_rank: Super Contributor
timestamp: May 31, 2022, 05:13:55 pm
content: Quote from: janoc on May 30, 2022, 09:52:27 amThe one thing you definitely would NOT do, if tasked with design of new high power density PSU, is to accept such poor efficiency target.Recently it's been understood that clever use of modern technology, and enough silicon, is actually cheaper than to spend money on aluminum heatsinks and fans. This is even just considering BOM. Energy savings for the customer are an added benefit.Given that transportation costs have skyrocketed in recent years, especially last year or so, power density pays back there, too.And to get that power density, you just can't arbitrarily increase cooling, youhaveto increase efficiency.90% is really a modern-day decent target but for such high power density, better aim higher, and you STILL need some rather noisy fan cooling, as you realistically can't get the dissipation below 200-300W no matter how good you are or design/BOM budget you have.

author: jonpaul
author_rank: Super Contributor
timestamp: May 31, 2022, 05:54:57 pm
content: Rebonjour, to the moderators (Simon) and veterans EEVblog super contribs...I am very curious...who is our friend Faringdon?The questions and responses seem very odd for just a DIY hobbyist,My advise is perhaps a waste of my limited time (very old guy here...)(:-:)Jon

author: Siwastaja
author_rank: Super Contributor
timestamp: May 31, 2022, 06:31:58 pm
content: Older long-time username treez.Seems to actually know something about switch mode converter design, and can do SPICE simulations. Has claimed to work professionally designing said supplies, usually in companies where management wants to pitch pennies in everything. Also does not like electrolytic capacitors, Chinese design, and loss of UK design jobs. Sometimes posts political rants as a result.Asks for advice for every possible small design detail. Usually has some weird idea about what others think is "normal" way of doing things. Instead of using a simple Google search to show this is not the case, he spends days discussing the strawman idea here, obviously not getting much work done as a result.Some can't stand him at all, some take him quite seriously. I think he's OK, most of the threads are technical and "to the point", even if a tad weird, but still good starting points for technical discussions. Too many threads? Just ignore most of them, and only look at one when you feel like you could get a small treez dose (recommended daily intake max 1 thread, with coffee). Some don't like the fact he's asking so much guidance for paid professional job. Others question if he's actually paid, or have ever been. Interesting character, nevertheless.

author: Gyro
author_rank: Super Contributor
timestamp: May 31, 2022, 06:41:42 pm
content: Quote from: jonpaul on May 31, 2022, 05:54:57 pmBonjour Jon,As you have clearly noticed, there is some 'history'. The initial identity of treez was changed to 'ocset' (he spawned several other identities but these were locked - other than 'Faringdon' which resulted in his original treez / ocset identity being locked). No, he is not a hobbyist, despite some recent claims, he has worked (actually contracted) for several dozen companies, including a rather undistinguished spell working on outdoor LED lighting (which is where much of the eye-rolling has stemmed from).I sympathise with your concern about your limited time. In fairness, it is probably simplest if you take a random browse though the previous thread title history and make up your own mind...https://www.eevblog.com/forum/profile/?area=showposts;sa=topics;u=139928Bon chance,Chris.

author: janoc
author_rank: Super Contributor
timestamp: May 31, 2022, 07:23:24 pm
content: Quote from: Siwastaja on May 31, 2022, 05:13:55 pmOh I have never suggested that that 80% should be the goal. I merely took that number as a common ballpark figure to estimate the cooling requirements because the OP didn't specify anything at all about the supply, apart from the dimensions. Who knows, maybe more wouldn't be achievable because of some (unstated) constraints.Even at 90% the required dissipation would be massive for that volume - at least 450W or so without any margins.

author: jonpaul
author_rank: Super Contributor
timestamp: May 31, 2022, 10:44:42 pm
content: janoc, based on my experience in the epoch 1970s...1990s:SMPS efficiency is a function of line and load, PFC, physical size and cost trade-offs,Linear supplies can be 40..70% but most SMPS are 80..95% efficient.Modern design topologies, type of circuit, switch frequency, choice of GaN or SiC switches ,soft switching and optimization of magnetics are all part of an energy efficient design.Of course a commodity consumer supply, e.g. from China, will be optimized ifor lowest possible cost, thus worse efficiency.See IEEE power electronics and industry application proceedings, PCIM, PELS, PESC and other power electronics conference proceedings over the years for state of the art development.bon courage et bon chanceJon

author: janoc
author_rank: Super Contributor
timestamp: June 01, 2022, 07:34:11 pm
content: Quote from: jonpaul on May 31, 2022, 10:44:42 pmJon, I am not arguing with youI understand all that. You are of course right - that's why I have mentioned also the 95% value in my original comment.I was only trying to explain how I came up with that 80% number, as a the kind of lowest reasonably expectable limit - I certainly don't think it would be a good target to aim for when designing a supply like that, especially not for a 4kW one!

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: June 02, 2022, 07:46:50 pm
content: Hey Treez, how's it hanging there?I'm in a bit of a rush but Google sponsored a competition to design a server power supply with very similar specifications.You should really look into the entries and the winners