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I feel kinda sorry for people purely reliant upon commercial products because from what I have seen there are many many false claims especially with regard to phrases such as MPPT. The solar industry seems particularly riven with fakes IMOP Thank you for the compliment, I was lucky to spend my...

Hello I have a ~1Kw inverter with two ~1Kw PV strings in parallel pointing in slightly different directions. As expected MPPT handled the combination with no problem even though there was a voltage difference. However what I was not expecting is that when up against the inverter power limit in...

Yes I am sorry I was a bit guilty of over-generalizing there, I didnt mean to exclude analogue and indeed one of the attractions of this micro was it's analogue peripherals and indeed they were not good (or numerous) enough for all functions so there are even real op-amp chips on the controller...

Just a quick note on the IMO, I use it and it's brilliant BUT it is not suitable for use outdoors unless protected because, 1/ The cable glands are not waterproof 2/ There is no waterproof seal around the operating mechanism 3/ The seal between the case halves is very flimsy and liable to have a...

I can help you with the green slime, it is caused by sunlight. On my IBC's I used for garden irrigation I forced heavy black polythene sheet between the steel cage and the plastic container and covered the top so no sunlight could get in, result, no green slime.

The shade has various shapes, sometimes leans in from the right (East) sometimes from the left (West) & sometimes from the bottom (South), so yup I had thought of landscape but also I would run out of space that way around. Probably someones firmware! If your familiar with micro-chip PIC...

How sad, blew up the inverter while testing (the new anti-shading software) today uhuhuhu Unfortunately blew up half the primary side bridge requiring apparently unobtainium IRFB4227's (except chink fakes) but fortunately found a guy in France with some genuine ones. I have done this before in...

See post #7!

******************* HAPPY NEW YEAR EVERYBODY ***************** Well Warpspeed as I say I was lucky, still lots of office politics but there was always the engineering to fall back on :) Hedges sometimes commercial development costs lots more than it should do because office politics and fools...

Abstraction is ok if you don't need exact timing and total control of the hardware! When you have self-destructing hardware with high energies around it's a bit better to have cast iron control of what's going on or BANG :unsure: usually expensive!! Ohh I wouldn't countenance anything...

That video way back in post #1 is very misleading. It quotes a fire authority who have no electrical engineering expertise simply based on there observations. I have personally observed in many instances incorrect equipment being used for DC breakers, most typically components designed for use...

Yup you got it exactly! There are some plots on another thread of mine illustrating this here

It all depends on weather your array suffers shading (as mine do) and large variations in temperature (most do), both cause vmpp to shift around in voltage at times quite dramatically, I can for example be running on only one of four panels(others being shaded) so vmpp is only one quarter of...

Yup just like here in Lincolnshire, I wanted to absorb those peaks without chopping them off by interfering with MPPT straight away and in many cases the average is nowhere near any sensible limit hence the thermal limiting by averaging over a long period as what I am really trying to do is...

Yes I noticed that, they are about the same ballpark 3:1 ratio so my situation is not quite as dire as I had thought. We get lost in Doncaster, it seems you have to go past the Racecourse at least 3 times to get from one side to the other :oops:

At last the replacement mosfets arrived UK post strikes allowing, replaced and waiting inverter re-installation to test. No more software breakpoints, even put a label on inside door of enclosure! EDIT 20/12 : Gahhh should have bench tested it but the gear takes a while to setup, anyway on...

Longevity of the inverter and panels! Ohmic losses (heat) increase at the square of current so if the opportunity arises to run at 10A vs 15A I will take it. Peak to average ratio is also important in the PWM as it affects transformer and inductor dissipation and so running at different PV...

IMOP that's quite likely a dangerous assumption, after all, it want's 5500W+losses from the input and it will use whatever combination of volts and amps it fancies to obtain it!

Ahh very interesting, do you know what Voc is for your array (measure with breaker open) then set the target voltage maybe 20V below Voc and make sure it sticks there as it's only operating point. I think your comments with a commercial product and similar parallel strings very relevant to this...

Well by the sounds of it you really are going to rely on that fuse for fire protection so I hope you take into account the mounting and cooling of that cable in calculating it's hoped for ampacity!

So to summarize your commercial inverter doesn't really have the facilities needed to control multiple parallel strings, I am not surprised as the available controls seem very limited. In your specific case the new string would be connected by a cable having a loop resistance of an Ohm, quite...

Hi all I have my own inverter design and a while ago I added periodic (~ every 10mins) voltage sweep to it so the MPPT could be kicked off of subsidiary peaks caused by shading, this indeed has worked very well. Now I have added a secondary array of panels on a Pergola roof to get a little more...

It's my own design and it is rather customized in that it is directly connected to a water tank heater that always gets priority any surplus being sent to the grid with export strictly controlled (as I don't get paid for it). The software is entirely assembly language for speed running on a...

Ahh yes but that would be more equipment at more cost. The purpose of the post is to show what can be done at minimal cost to improve performance, in this case by having arrays with different sky views. Depending upon the inverter it may be possible to add dissimilar strings without investing...

What you need to take into account is the distance through the earths atmosphere the sunlight has to travel before hitting your panels, atmosphere seriously attenuates sunlight due to suspended dust, water vapor et etc. So the lower the sun is in the sky the lower the panel power even if they...

I see what you mean, some call that progress, others not. I use the tools of the time at my disposal and were it not for the level of integration the project would have been impracticable given my limited resources.

Hi all, I have a completely DIY setup (excluding the bought panels) that has been running since 2015. We moved house this year and the new location is definitely sub-optimal, ground mount with bad shading from buildings and trees especially now in winter. I have looked at many options like...

Battery ??? Don't have one of those, my primary load is a 3Kw/240V water heater, so I store my energy as hot water. If I needed to I could go 6Kw in a single string within the easily available tech (MOSFETS). More than that and I would have to dust off the thinking cap :LOL: Absolutely spot...

Hello, I can add some information here as I actually designed some additional software for my inverter to do this sweep periodically, thread here The primary purpose is of course to jog the mppt off of false maximum power points when the shading diodes are in action, for my array typically at...

Have you tried east and west or sse & ssw ?