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Forum Index : Electronics : Inverter building using Wiseguys Power board and the Nano drive board
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KeepIS Guru  Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
In case anyone is interested. I finally had some MS226060-2 arrive from an AliExpress site that has the slowest delivery time I've seen, Site keeps saying my order is canceled due to shipping delays, then they issues a new consignment tracking number, no tracking info and then after a month or so, it suddenly appears at my doorstep via DHL. Toroids 57.1x26.4x15.2mm It's the last on on the list, click "View More" to expand the list (57.1x26.4x15.2mm) These are the original meatier (smaller hole) Blue Toroids that I use, they will just fit 5 turns through a six Stack of Toroids for around 23uH, 4 turns will give 16uH. You need 12 of these Toroid Rings to make two x 6 stack chokes at either 16uH or 23uH, the price shown is for a 3 pack. And just to make me want to bash my head against the sharp edge of a desk  Replacing a temporary 40uH Toroid choke in one side of the "Test Inverter" with one of these 23uH chokes, which matches the existing 23uH choke in the other side, has completely eliminated the Buzz I could induce into the Toroid by fast stepping the DC input up or down. It still makes a slight Buzz as you fast step the Voltage up, but as soon AC regulation is reached, the buzz stops and the Toroid remains silent (ear against the Toroid) Made a slight miscalculation in the Inductance, 4 turns 16uH, 5 turns 23uH.  . Edited 2025-05-22 11:43 by KeepIS NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
There is a difference in the Toroids, these New units are marked as FM571060A, the old Toroids are MS226060-2. I cannot find any reference to FM571060A. They both give exactly the same Inductance for the Number of turns and are the same size. The newer units look to have a much softer curve. I have repeated the tests many times and every run is identical. Yellow: Current 125A per volt. Blue: Cap discharge voltage from 75V. Original MS226060-2 Toroids:  The New Toroids:  If you compress the time scale, the second image is virtually the same as the first, it's almost as though there is a small resistance in play? I rechecked the cable, both use the same cable, everything looks identical and the display for each as shown above is always exactly the same no matter how many times I swap them into the JIG. EDIT: At 625A, the Cap voltage (blue) has dropped from 75V to 58V, there is still plenty of reactance left. If the Choke is replaced with the same winding lenght cable, the Cap voltage trace is simply a narrow pulse from 50V to 0V ("almost" zero inductance). A single power board bank of FETS handling 625A would not see anything like a short, especially as there are effectively two chokes in series with the Toroid. So "32 FETS" and FOUR chokes in a Dual Inverter can easily handle 800A peak Induction motor start loads. BTW: I proved that if built correctly, a single wiseguy Power board with two chokes and one Toriod, can easily handle repetitive 650A Peak start loads daily for months. . Edited 2025-05-23 12:03 by KeepIS NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1135 |
Looks good, couldn't find any reference to that part number either...not that surprised that its not listed, quite a few of them don't seem to be listed, I have 2 large cores with unknown numbers.  Anyway it appears to have removed/dampened the Buzz sound, My old Mad inverter has a buzz sound when it starts the induction motor on the saw bench, start surge of about 8Kw, sounds a little like hitting it with a hammer as it still uses the old silicon steel U cores.  Cheers Aaron Off The Grid |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
That's good to know, I'm very happy with the new cores. BTW I've been reviewing lots of old data from the Single 3 stack Toroid Inverter compared to the dual 3 stack Inverter and the startup currents have dropped in the dual. The power levels haven't, it's just the Dual Inverter having less AC SAG under extreme loads and recovery is quite fast. It's obviously why I'm getting zero flicker of overhead lights. AC voltage SAG is now so small that annoying pulsing loads have no chance, even switching 2.8 kW AC pulsing loads on top of an almost unloaded Inverter load of 200W, does absolutely nothing to the lights. To get a LED batten to flick once, I need around 12kW of load suddenly dropped across the AC output, seriously Impressive.  NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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| analog8484 Senior Member  Joined: 11/11/2021 Location: United StatesPosts: 138 |
Interesting that a small difference in chokes can make that much of a difference. I wonder if the older inverter builds using only one choke had more buzzing. |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
I think the balanced chokes and inductance change just shifted the level needed to induce the buzzing, I realized that it just takes a bit more to get it to buzz  Many differences in earlier builds including different SPWM modulation compared to the Nano, and they often used buzzing ferrite E-core chokes, so many variations that to tie it down is again like trying to head cats. Put a resistive load on the inverter and the idle buzz is gone - my Inverter never idles NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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oreo Senior Member Joined: 11/12/2020 Location: CanadaPosts: 108 |
Here is a cross reference I pulled from the Karson's website  Different manufacturers unfortunately use different part numbering schemes, however the FM part number seems to follow the same scheme as CSC part number. However it is obviously not a standard sendust core material, because it saturates differently. Let's run a few calculations. Greg |
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| oreo Senior Member Joined: 11/12/2020 Location: CanadaPosts: 108 |
Using the curves from 6 MS226060-2 cores posted earlier by KeepIS.  Now running the same setup in the Micrometals analyzer produces slightly different results. I do notice that KeepIS curves are a little funky in that the voltage is shown as going up for part of the curve, which is weird. Typically the Micrometal calculations match my curve calculations but regardless we can use this as a guide.  Now there are better core materials than Sendust. Here is a list of the Micrometals (Arnold cores) materials.  Now if I plug in a HF type core into the Analyzer tool, this is the graph I get. The FS type core produces slightly better results. These cores saturate slower than standard sendust.  So it looks like KeepIS has discovered a core supplier that can supply cores with better characteristics than a standard sendust core. That is good to know! Greg |
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| oreo Senior Member Joined: 11/12/2020 Location: CanadaPosts: 108 |
On a different note, I was experimenting with the frequency setting on the inverter. Can you advise what difference we should be seeing from 60Hz to 60-Hz to 60-- Hz? thanks! Greg |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
oroe thanks so much for that, I was going to ask you if you could run this through the Micrometal app as you did last time. This confirms my calculations and the much slower saturation curve for the Latest toroids  I'll look up the nominal difference at 60Hz when I get back, I'm not at the Workshop PC. The variation is small and the exact frequency will vary slightly between Nanos with Xtal accuracy, but you likely knew that. EDIT: these are ballpark figures, as I said will change slightly with xtal tolerances etc. It shifts roughly +- 0.08Hz. Let me know if yours is out? . Edited 2025-05-25 14:06 by KeepIS NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
I had already calculated the old Blue toroids and obviously got the same results, however these still don't show the real picture, especially as the Voltage sags and throws out the intersect points for accurate calculations, but good for comparing different sets of Chokes. I'm going to make a new Sat tester with max current limiting and stiffer Voltage, testing a choke at working voltage and current does change the results somewhat. BTW the Micrometals Sim above is 4 turns, I have 5 turns in these @ 22.6µH @ 20kHz. Edited 2025-05-25 15:53 by KeepIS NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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| oreo Senior Member Joined: 11/12/2020 Location: CanadaPosts: 108 |
oops. With 5 turns the simulator returns very similar numbers to the calculated numbers from your curves.  For reference, I built this circuit, using just 1 555 (using storage scope), a voltage regulator and 6 FETS so I could crank up the current and voltage. I have 52,000uF (overkill) and the voltage drops 1.7v after supplying 800A for 50uS. After seeing these numbers, I can better understand how easy it is to kill FET's when you have a fault which essentially shorts the capacitor bank. Greg |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1854 |
I have always imagined FETS with 40kW of LiFePO4 battery @ 53 volts with 40000uF on one side and looking into a Big Toroid primary wound with a relatively short length of 50mm2 cable and a load condition that makes the Toroid primary look like a dead short  That's why I harp on about using two * 6-stack chokes which allow a good winding length using a slightly smaller gauge cable. The small resistance in the choke cables combined with any remaining inductance in the Chokes are all that stand between FET Survival and FET Heaven under high current trip conditions It may come down to just the Choke cable R-loss that gives the FETS the last buffer to survive long enough for the current trip to kick in. The following values are out a bit because falling REF DC throws out (increases) dt and no allowance is made for winding R-Loss or Jig switching R-Loss. BTW there is no current shunt R-loss. CS571060 5T 6S Choke resonant inductance @ 20kHz = 22.6uh DSO: 75A = 23uH (75.9V) 125A = 19.9uH (75.4V) 250A = 15.4uH (70.2V) with dt reduced by 20% . Edited 2025-05-28 10:52 by KeepIS NANO Inverter: Full download - Only Hex Ver 8.1Ks |
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