ChristoSnake

Thanks for all the comments!
Here's a graph plotting inverter load, battery & grid power during the same time.
The spike in the middle (12:30 - 13:10) was a 2kW hot water element turning on (via Geyserwise timer) to give our evening bath water a temperature boost.  Smaller spikes due fridge/freezer motors, and base load mostly swimming pool pump and a few computers.
I am not allowing AC charging, only PV.  The time and current based charge is set for <1 A for 60 minutes and <48.6 V, so it should not interfere.  I'll see what it does today with CC = CV, as reference, then try again with CC > CV tomorrow to see if I can reproduce the weird behaviour.
se dangerous "iron" PS:
PS: I notice a lot of comments about "ironing".  I presume that it refers to the dangerous action of applying extreme heat to non-wrinkling fabric for the purpose of prematurely aging the fibers so that you have an excuse to buy new clothes?  I'm glad to report that we do not own any of those evil devices and would never consider taking part in such unnatural rituals :-)

Hi P1000 , you were absolutely correct that the switching losses are lower on 4668 than 4468. I have two identical 2.5kW dc-dc converters on the bench that I am exciting manually  , one set is standard fitted with 8 x 4468 on the battery side and one set fitted with 8 x 4668 (repaired).
The +12V driver side of the 4468 converter shows about 400mA total  , that of course includes the 4x igbts on the high side and the system supply as well .   The 4668 side draws only about 120mA .  I assume that is the price we pay for the fact that the 4468 has such a low Rds ?
I have integrated the repaired module back into the InfiniSolar  inverter and tested battery mode operation under no load . In the next couple of days I am going to put the system under incremental load increase , and monitor. I am considering mounting two 18B20 temperature sensors on the heat sinks in order to compare heat dissipation under various loads.
Thank you for your and @Coulomb's valuable info on the 4468 vs 4668  provided , that's already nearly a year ago !

I concur with the problematic DP at the top right - it will block the hot air coming from the fan exhaust finding a natural way upwards out of the cabinet.  That hot air will find it's way around the front & bottom of the inverter and get sucked into the inlets on the left of the inverter.  Once you feed hotter air into the inverter, you'll get hotter air at the exit, etc. etc.
You may get around a lot of that by making use of passive ducting to channel hot air away and keep it from interfering with cold air that should be drawn into the inverter.  I have two suggestions:
Cut a large circular or square hole (depending on available tools) at the left bottom of the cabinet to allow cool air into the cabinet when the door's closed. Make a duct out of whatever you have lying around - carton, polycarbonate sheet, a (probably illegal) corrugated carton sign on a street pole, etc.  Use this to channel air upwards out of a similar hole you drilled at the top of the cabinet. I used the second part of my advice to you to redirect air upwards towards a ceiling fan right above my inverter, instead of blowing it indiscriminately into a small scullery.  The duct is closed at the bottom, flush against the electrical trunking on the right, and open at the top.

I concur with the problematic DP at the top right - it will block the hot air coming from the fan exhaust finding a natural way upwards out of the cabinet.  That hot air will find it's way around the front & bottom of the inverter and get sucked into the inlets on the left of the inverter.  Once you feed hotter air into the inverter, you'll get hotter air at the exit, etc. etc.
You may get around a lot of that by making use of passive ducting to channel hot air away and keep it from interfering with cold air that should be drawn into the inverter.  I have two suggestions:
Cut a large circular or square hole (depending on available tools) at the left bottom of the cabinet to allow cool air into the cabinet when the door's closed. Make a duct out of whatever you have lying around - carton, polycarbonate sheet, a (probably illegal) corrugated carton sign on a street pole, etc.  Use this to channel air upwards out of a similar hole you drilled at the top of the cabinet. I used the second part of my advice to you to redirect air upwards towards a ceiling fan right above my inverter, instead of blowing it indiscriminately into a small scullery.  The duct is closed at the bottom, flush against the electrical trunking on the right, and open at the top.

I concur with the problematic DP at the top right - it will block the hot air coming from the fan exhaust finding a natural way upwards out of the cabinet.  That hot air will find it's way around the front & bottom of the inverter and get sucked into the inlets on the left of the inverter.  Once you feed hotter air into the inverter, you'll get hotter air at the exit, etc. etc.
You may get around a lot of that by making use of passive ducting to channel hot air away and keep it from interfering with cold air that should be drawn into the inverter.  I have two suggestions:
Cut a large circular or square hole (depending on available tools) at the left bottom of the cabinet to allow cool air into the cabinet when the door's closed. Make a duct out of whatever you have lying around - carton, polycarbonate sheet, a (probably illegal) corrugated carton sign on a street pole, etc.  Use this to channel air upwards out of a similar hole you drilled at the top of the cabinet. I used the second part of my advice to you to redirect air upwards towards a ceiling fan right above my inverter, instead of blowing it indiscriminately into a small scullery.  The duct is closed at the bottom, flush against the electrical trunking on the right, and open at the top.

I "only" have 24 panels, so it never went over 500 V per 12 panel string.  But 500 V DC is enough to cause a lot of trouble if it finds a path with a lower resistance, as @Coulomb often mentions.
The strings are now wired differently to cater for the 8 kW Sunsynk's lower voltage MPPTs.

its mid-winter here on the Highveld  , and if you can imagine how slow molasses move on a very cold winters morning , well that's me . But I have made a small advancement on @ChristoSnake infini . I have repaired the faulty mosfets/igbts on the battery board with temporary low current devices for testing purposes. Then excited the 3525 PWM circuits , and fed 5V on the battery bus . The switching waveforms on the semiconductors igbt's and mosfets number one. I am running out of power supplies though , you really need plenty of them. 
So with 5V on the battery terminals I got 34V on the dc bus , which suggest about a voltage transfer ratio of 6.6 factor , sounds about ok.
Next up I am going to test the reverse direction . from dc bus to battery . Then increase the voltages . so its pretty much scalable tests , I am very cautious with the infini in this regard.

Just want to share the basic bus topology of  @ChristoSnake  ' 5kW Infini grid-tier . Below is a very  simple schematic of the low voltage battery bus and the high voltage bus , showing the DC-DC converter and buck circuits , but not the DC-AC converter. What I want to point out is the split supply HV DC bus that I have previously mentioned.

1. On the left hand side is the low 48V battery dc bus . Noteworthy is the fact that there are 2 x 2.5kW  sections. I  initially thought this was just dual effort to split power , but no , its dual in order provide a split high voltage dc bus .What's nice on the infini is that this module is a separate board , and on it the supplies are generated isolated , i.e. complete independent. Only on the main board are the two N terminals joined , as to effectively form a positive bus wrt to neutral , and a negative bus wrt to neutral . 
2. So what's the deal with split supply ?  . For a single ac output , nothing , because the ac live and neutral can be  performed via full bridge DC-AC converter from a single bus supply. But the moment you go multiphase , 2ph or 3ph, you cant go full bridge because guess what , your neutrals cannot be tied together  from the individual full bridges. So there are 2 options , you either use a split dc supply and then use a half bridge centered around a hard fixed neutral as shown above . Option 2 is you use a delta to Y conversion transformer , which for my untrained eye seems to be expensive , but some of the large three phase machine like the ATESS 100kw use this isolation transformer to create a hard neutral for unbalanced loads . I guess the isolation  feature becomes important !? 
3. The buck circuit is not your average Axpert circuit , instead there is an igbt instead of diode . This makes me think that this might be  a buck-boost configuration , not only buck . @Coulomb would you agree ?
Although @ChristoSnake 5kW machine is 5kW singe phase , it has been designed for a 2ph split ac supply  . The main board merely combines to two supplies , so internally this machine is really two  2.5kW inverters in parallel !!!
Christo's machine suffers from a short on the battery bus due to some mosfets shorted. I have already isolated them . The beautiful thing is the both the mosfet and igbt drivers are pretty much stock standard as we are use to on the Axperts.  mosfets and bridge igbt's are built around the standard 3525 PWM chip with isolation transformers , so its actually very easy to stimulate them with a 12V and -12V supply . The buck igbts is not so easy . The buck igbts are controlled from the dsp , which I can simulate with my pi pico controller , but the isolation transformer is driven from the SPS main feed which is the damped oscillating output  from the SPS flyback transformer. That is my next challenge , I cannot generate that waveform , but I could probably inject a 9-15 volt ac transformer output in order to equal the energy magnitude and 20V ac peak requirement.
 
 

When I went to bed , I revisited all my procedures , and came to the conclusion that the ideal test bed for the IGBT full bridge will be to remove the large HV capacitors and replace with a small electrolytic, just enough to smooth the bus , but low on energy. It's no use using a current limited power supply on the battery end.bottom line is these big caps accumulate a lot of charge.
Then the remove the controller card, and use a test controller to pump the bus soft start  to something like 80 volts pressure. Maintain this voltage by reading back the bus voltage into the test controller.
Then generate the 4 timing pulse trains for the igbts with the test controller.its not that difficult . The PWM can be rough to generate a reasonable sine wave. If all goes well, ramp up the soft start to ultimately 310v.
I have actually started with this morning , and going to use it on @ChristoSnake Infini , which I am busy debugging.

Yesterday I nearly decided to stop my journey , pack my solar suitcase, delete my forum account, and walk off in the sunset.
I have done so much homework in order to leave very little if any to the imagination regarding the repair of faulty IGBT bridges. And yesterday I started with great confidence on a machine that was destroyed due to inadvertant grounding of a PV terminal.
So I removed the 4 DC-AC converter's IGBTs and heatsink. Then switch on and check the drivers on DSO. All four looked pretty good, voltage levels -5.4 for turnoff and 15v for turning. Waveform shapes pretty good to my own basis of comparison.
Ok next I temporary solder test igbts onto the board  ,in two test phases  of half bridge only as I have described earlier in this topic. Passed, then I solder all 4 in full bridge mode . Switch on . 220vac beautifully. Doesn't get easier than this.
Then I left it running for a while , and because the igbts are not heatsinked, I touch the plastic case with my bear hands to gauge temperature.BOOM !  the abrupt  explosive sound so  heavy that I was completely deaf for a couple of seconds , then partial deafness for a good two hours after the bang.
I was devastated to say the least , this is not on , and somewhere my procedure have exposed to be flawed. I investigated the circuit and found the gate pin of the IGBT that I touch to be loose , dry joint.!!!!
HA HA , I felt better. Here is the thing .once a gate pin is left hanging , guess what ,the valves meet the pistons, timing belt broken.  The high impedance of the gate will  create indeterministic switching.
LESSON 1 when you do temp rigging , check the quality of your connections/joints.
So no I remove the 2 faulty igbts (it's mate in the same bridge leg will also get destroyed. Turn on and check waveform again.passed.
Solder 2 new test igbts in and this time used about 100 grams of solder to secure connections. Switch on .BOOM.BOOM.  now you can understand my opening statement.
I have now lost faith.  But our fathers have not raised scared children , reckless yes, but not scared. This time around there was no dry joints. I removed the 2 faulty IGBTs again , and tested the driver waveforms again and again and again.ha ha .one driver had a shaky -5 volt trace , what's more the waveform edges not so good anymore. Start tracing the driver.now the gate series resistor is 47R . But it measures around 30k.Shit , so the igbt went faulty due to the first BOOM  and blew this resistor   . But not open circuit , enough resistance to fool the DSO, but this resulted in very bad switching performance if the new IGBT that went during BOOM 2. So basically the we cannot switch the IGBT on abruptly and we cannot switch it off in good time.And that's what caused the BOOM 2. 
LESSON 2: please check this resistor even though your driver waveforms looks ok.
There was no BOOM3.  I feel better now.lots of lessons learned.

Is a TOU tariff available? COJ offer something they call "time of use" but it's really just paying a little more in the winter (irrespective of time of day) and a little less in the summer. So it's seasonal, not time of day.

In much of Europe they have true TOU tariffs, and people run their dishwashers in the wee hours to take advantage. 

My gut reaction was that TOU will just move the peak, but it can only move it so far because families have to be fed and folks have to have a bath or shower, and then they all go to sleep.

So I don't believe that it's just folks with an alternative supply that should be on a TOU tariff. Everybody should be. 

Once there's no load shedding of course. Because when you're without power for 10, 11 hours a day, you have to charge and cook and make hot when you can.
 
Yes. I sometimes have to charge up in the evening, but I try to avoid peak times, and I try to wait 30 minutes after power is restored. So far I'm able to do that, my battery has always lasted long enough.

I wonder how much of a problem these trolley inverters cause. Their charge current isn't very high. Though I suppose if you have enough of them, AND geysers etc.

I have heard tales of people loading the oven and turning it on whilst there's shedding, so that supper starts cooking as soon as possible. There would be a lot less surges on restoration if people would just turn their geysers and stoves off, then turn them back on a few minutes (or more if they can hold out) after load shedding. But asking people to do that won't go down very well. 

We are mostly off the grid.  Used to consume around 800-850 grid kWh/month, now we're down to <10 kWh/month.

We are mostly off the grid.  Used to consume around 800-850 grid kWh/month, now we're down to <10 kWh/month.

We are mostly off the grid.  Used to consume around 800-850 grid kWh/month, now we're down to <10 kWh/month.

You're welcome to take your time to get acquainted with that beast of an inverter...
It may also be worthwhile to reach out to @Youda.  He has a <insert appropriate collective noun> of InfiniSolar 5kW inverters and seems to know their workings inside & out.
PS: I'll bring a smaller vehicle next time 😉

Enters the Infinisolar Inverter 5kVA Single Phase
I have now entered unknown territory , the Infini series. @ChristoSnake delivered the above model for repair.  Nice guy , good to meet . I think he was aware of Germiston roads being terrible , because he arrived with a larger than life Nissan Patrol , absolutely beautiful vehicle , which amongst other amazing things  , he has done several upgrades.  Offloaded the machine , so this gives us the opportunity to try and learn the inner working of this grid tied beauty. 
After opening the bonnet , I am very impressed with the layout and overall quality. Its slightly offending with its presence  , like the Nissan Patrol , because I am so used to the Axpert by now . But here is the beautiful thing   , one start to relate to the machines subsystems as you expect nothing really out of the ordinary. The analogue power train is as expected , obviously all the intelligence lies with the DSP control board , and the latter looks like a complicated beast just looking at it.  Its even got a slave DSP controller , along with the Master controller, ouch , this is @Coulomb territory  ,big time.
Its a double story layout , with the power supplies (SPS) and DC-DC converter on top . In the basement is the large DSP controller board as well as the DC-AC converter (main board). Now this I love to no ends , the DC-DC  and DC-AC all-in-one on the Axpert , but on Infini  they are modular , separated . Interestingly , the high voltage DC bus caps are not on the main board , but separate cluster of capacitors. I would like to know why there are so many ( i think there is  6 or 8  large 470uF 500V caps).
The SPS is your typical SMPS's 12V , 5V -12V  concentrated from PV, Grid and battery.  The DC-DC converter looks pretty straight forward , 2525 PWM controller . Interestingly there is 2 sections in parallel , each delivering 2.5kW.  The mosfet and igbt drivers also onboard , as expected.
I have disassembled nothing so far . Only thing I have done is I tested for short circuit on the battery side , and low and behold , 0.2 ohms !  . So I will be starting with the DC-DC board , which I am  going to remove as a standalone circuit board.  I will be taking it slowly and easy though , but looking forward to  this part of our repair journey .
Circuit diagrams are non-existent , and I don't think @Coulomb has partial schematics . There exists not even a service manual for the 5KW (I see Coulomb has uploaded a 10kW one , which has given me some insight already). But guess what , these are the rules of engagement , and we will see how the knowledge we have gained from other power trains , will help us here .
 
 

We're on the Mooikloof substation and we had 11 days without electricity when the stupid thing burned down in December 2021.  We're running in grid-tied mode and our stats show that we've used 3.3% of grid power for the year to date.  But more importantly, we made it through that extended outage last year without ever being in the dark, having cold bath water, not being able to use the washing machine or dishwasher, eating cold food, not running pool filtration & borehole pump, etc.  We pretty much went about our daily lives as if nothing had happened, except for the racket of everybody's generators making it tough to sleep at night 😃
I've also considered getting rid of that last 3.3%, but much of that grid usage is due to way grid-tied inverters work when the grid is available.  Once the grid disappears they go into off-grid mode, and there's nowhere to leak power from (except PV or batteries) while they keep up with load changes.  I think that I've made my peace with remaining "mostly off grid"...

Some practical examples may help...
I run 2 strings with 12 panels each and the strings *just* breach 500V on a partly cloudy day (String 2 had a 510V peak on Sunday).  Voc on my panels are 45.6V (for a 547.2V theoretical max) and my roof has a 17.2 degree angle.
PS: My inverter is capable of 900V per string, so I'm actually thinking of adding more panels 😁

Nice setup, but you forgot to install the last row of 4 panels on the right-hand side of your roof
I have nearly as many panels as you have, and in summer my batteries usually recharge before noon.  After that I use the spare energy to boost the water temps in the geyser.  And later in the day the famous Pretoria summer thunderstorms make sure that there's no more generation to be had!
In winter the batteries take a tad much longer to recharge, but at least we are blessed with cloudless weather so it does not really matter...

Not a problem, according to Pylontech:

You've already tried two different sources/versions of the software, so that's probably not the issue.  When you run the software, make sure to right-click the .exe file and use the "Run as administrator" option:

 
Spreading your home's load over the the course of the day is the easiest way to ensure that you do not run into overload situations.  I run a borehole pump for sprinklers from 08:30 - 09:00 every monring, then the swimming pool pump after that until end of the day's sunlight (via Tasmota & NodeRED home automation).  Our solar geyser's 2 kW element is only allowed to give it a boost (via Geyserwise) in the early afternoon in case of heavily overcast weather.  During the geyser's time slot the pool motor will switch itself off via the home automation to provide spare capacity should we turn a kettle on, or decide to cook.  That's the reality of life without a split DB box & only 5 kW worth of InfiniSolar...

I fully agree with the good advice provided so far...
The specs you provided clearly states the rated output power as 3kW.  We know your inverter's overload alarm triggers & the fans are running at max speed, but somehow you insist that the inverter is "cold as ice" and all is fine!
Remember that the specs are there for a reason - they come from the ratings of the IGBTs, diodes, etc. that are used in your inverter, as well as the ability of the fans to deal with the heat generated when you run it hard.  You may exceed these limits for short periods of time without obvious damage, but in the longer term you will destroy your inverter.
As for your question about the SolarPower executable that does not want to open... I assume you are not running this on the Raspberry Pi connected to your InfiniSolar?
 

Suppliers should be geared up to deal with support for Pylontech modules. 

I have service manuals for the InfiniSolar 3kW & 10kW "Plus" models. This bit of overload spec comes from the 3kW's service manual and I can only guess that same design principles hold true for all the InfiniSolar "Plus" models:

I've pushed mine to around 8kW for short bursts (arc welding, mostly)...