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Permanent master slave GTIL2
#21
(08-24-2019, 02:34 PM)Doin it Wrote: Korishan a do u know anything about the Iotawatt?

Not directly. I've built my power monitor based on the OpenEnergyMonitor project. But they are similar in how they function.
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#22
completely charged U said the cts would haveto be spaced apart as far as the moon lol..well with single phase power company supply ppl are putting cts on some individual loads so the inverter connected to those individual loads only get supplied power from inverter if the other inverter isn’t fully supplying

Korishan do u think the iotawatt would have someway of adjusting-calibrating the voltage reference..I was talking to wolf about this on the advice for gtil thread

What they (ppl who designed the gtil2) really should have done is allowed the second inverter to be connected to the first inverters internal limiter so the second inverter only supplies the power the first inverter isn’t supplying. I had my hopes up that they made them this way...but someone said they tested it and did not work...the sensor cable was connected to the external port of the second inverter and then another plug was put on that cable (no cts) then connected to the external port of the first inverter, also first inverter was using its internal limiter and internal limiter connection and cts on mains..they should have made them to work this way
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#23
(08-24-2019, 04:26 PM)Doin it Wrote: Korishan do u think the iotawatt would have someway of adjusting-calibrating the voltage reference..I was talking to wolf about this on the advice for gtil thread

Probably, but I don't know. I haven't used them so not sure. Maybe posting a thread specifically about calibrating the Iotawatt, others here who have experience with it will chime in (remember, not everyone reads every thread, especially if they don't happen to have that device listed in the topic). I know there are several who do use it. There are a few threads that talk about the Iotawatt system.
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#24
Yeah I read them all lol no life,,,I’ll start another thread specifically about that thx, well not all of them but a lot..
Some ppl here might use iotawatt but very few anywhere use a 240volt reference for USA residential power supply...I want to do it this way cuz it’s more accurate to use a 240volt reference and even more so more accurate when loads on each leg get unbalanced..
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#25
(08-24-2019, 04:10 PM)Doin it Wrote: Wouldn’t that change the total output that the second inverter needs to put out to cover loads
Yes, but overall the two GTIL units would balance the visible CT current to zero.

(08-24-2019, 04:26 PM)Doin it Wrote: completely charged U said the cts would haveto be spaced apart as far as the moon lol..

What they (ppl who designed the gtil2) really should have done is allowed the second inverter to be connected to the first inverters internal limiter so the second inverter only supplies the power the first inverter isn’t supplying.

Based on speed of light (volts down a wire) and the time it takes for the PID in the GTIL to respond.... about 8x the distance to the moon.


Running one unit up to max before the second by design is less efficient overall and the use case of two units running off separate power sources is rare..


The setup you have in the circuit outline is not ideal as you can end up wasting solar from array 1 which could be used to charge the pack..

I would rather put the GTIL units into battery mode, hook both solar arrays to charge controllers and have the GTIL's run off the DC battery rail. This would guarantee the minimum amount of solar is lost, maximisre the load matching from the GTIL's and use the batteries when needed.

"This would prolong the lifespan of the batteries"
With a battery pack you have x number of cycles left so I would have thought using them as and when you can (and replace the battery pack when needed) would give the most benefit. Unless it is for blackouts or the pack is too small to keep the discharge rate  well under 1C (larger than 4kWh).
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#26
So your saying the system would still (with extra resistor) cover as much of the loads at any time as it does without the extra resistor u are referring to?
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#27
Correction, maybe only 1x (2.5 seconds), lol.

https://en.wikipedia.org/wiki/Earth%E2%8...munication

(08-24-2019, 05:35 PM)Doin it Wrote: So your saying the system would still cover as much of the loads at any time as it does without the extra resistor u are referring to?

Yes, in theory.

The secoond GTIL would see say 100W and increase output to a target of +100W, however after increasing output by say 50W the target W would still be say 80W.

Should do something like this

Load    GTIL(see)  GTIL target GTIL Out
1000W   100W       100W        20W
980W    98W        98W         38W
942W    94W        94W         55W


In the case above the GTIL is seeing 10x less load with a 10x smaller resistor
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
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#28
If the second inverter is seeing 100w or whatever instead of the actual amount the loads need then how can the second inverter fully supply whatever loads are left that the first inverter can’t supply...if the loads are 1000w but inverter only produces say 500 or 800 or whatever amount of that than it’s still not producing all of the 1000w...are u saying that the second inverter would just keep increasing its output till all loads are met. But wouldn’t the second resistor change the total amount that the second inverter shoulda been supplying so second inverter thinks it’s supplying all the loads even if it’s not...for instance if the inline resistor that comes with the 240v dual sensing cables did not have the resistor, the inverter would then supply double the amount or half the amount the loads actually are or something like that

Having both arrays to one battery bank u said the batteries would only get used as needed but they are used the entire time the inverters are powering loads...the way I’m trying to do this, with a master directly to pv and slave on bats, system would only use bats when master inverters pv cant keep up with loads so most of the power the master has available from direct pv most of the time will be getting used most of the time by constant loads...during peak solar time of day, then yeah my constant loads are less so some waste there but my batteries would not be used during the entire time (most of the time) master inverter was covering all loads...
So really the batteries wouldn’t get used no where near as often and would stay full more often with less cycling so prolonging the life of expensive battery packs. Also in the evening only slave inverter (only inverter drawing off batteries) would be using the batteries as to not draw off batteries as hard as 2 inverters would, without needing to use settings...I believe I would also use a switch to allow both arrays to charge batteries during power outages and have off grid inverter connected to the bats aswell. My charge controller would have to be able to be handle the amps of both arrays aswell as one array
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#29
I would think running inverters off of separate power sources would be common..if someone has multiple higher voltage or lower voltage grid tie inverters they have to be powered by separate power sources if batteries aren’t used.
Yes in general running an inverter to its max power output is not as efficient as running the inverter at less output. But when 2 inverters are connected to batteries aren’t both of the inverters running at close to max anyways, I guess they wouldn’t be maxed with lower loads, but adding another inverter to supply the loads that one inverter could have handled itself is also adding the losses of using a second inverter
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#30
This is missing the PID math (quick chart for the example) which would track to zero quicker and the picture/chart should be easier to see



GTIL 1 should end up at 900W and GTIL 2 ends up at 100W (should be lower due to the way the PID would track)

Think of it as just tracking and the CT just says how urgent to track. The CT just provides a direction (not the absolute value) so a smaller input value would just track slower and still stop eventually when the net CT is zero.

"less cycling so prolonging the life of expensive battery packs" - you need to really think through what your implementing and what your real goals are, economics or environment or learning or a compromise.....

"if batteries aren’t used" - completely different scenario, batteries can change everything.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
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26 User(s) read this thread:
hbpowerwall (08-22-2019, 03:06 AM), sl1me (08-28-2019, 03:47 AM), Wolf (08-25-2019, 02:27 AM), Solardad (08-25-2019, 08:10 PM), ajw22 (08-23-2019, 03:26 AM), OffGridInTheCity (08-22-2019, 12:53 AM), 100kwh-hunter (08-24-2019, 12:22 PM), Doin it (08-27-2019, 04:08 AM), solarsteve (08-31-2019, 10:38 AM), Otakar (08-05-2019, 09:38 PM), berthfield (08-24-2019, 01:56 AM), suntan901 (08-14-2019, 01:53 AM), emuland-metroman (08-23-2019, 06:47 AM), neowolf (08-30-2019, 09:23 AM), daromer (08-22-2019, 04:19 AM), Sean (08-25-2019, 08:47 AM), Korishan (08-25-2019, 11:13 AM), jdeadman (08-26-2019, 01:22 AM), wim (08-24-2019, 06:52 AM), watts-on (08-25-2019, 10:00 AM), Geek (08-23-2019, 03:22 AM), Ivo Staelens (08-24-2019, 05:51 PM), CarelHassink (08-25-2019, 06:36 AM), completelycharged (08-24-2019, 08:14 PM), Riplash (08-22-2019, 12:34 AM), nettermann90 (08-20-2019, 10:13 AM)

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