Ep03 DC solar monitor - it's working!
Ғылым және технология
If you have a hybrid inverter you will be familiar with the problem of not being able to see the kW readings for the DC battery and the DC panels on the Myenergi app.
Well, not anymore! In this video series I'll take you on the long journey I went through to solve the problem, or at least have a pretty good indication of what is going on behind the inverter. Be warned this has taken several months so the video is split into many parts as I went down lots of blind alleys!
In this video we will go into more detail about how it works including performance specs. But I think we can do better and there is more to come . . .
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Some notes:
If you have an AC coupled battery (Libbi) this can be read directly with an AC CT into the Harvi. Job done.
Back to a hybrid inverter - with a DC batt + DC panels you could also hook up the RS485 into Home Assistant software on a Raspberry Pi and get the readings that way.
But I wanted them on my Myenergi App on my phone . . . so here we are!
Пікірлер: 6
Your AC transformer will either be in-phase or 180° out depending on which way it is fitted to your board. So you need the cable markers.
@routercnc9517
9 ай бұрын
The power socket is installed the same way for both sockets and the circuits are the same so I think they wire them up arbitrarily inside the transformer. Not a problem to swap the pair going to the Harvi to reverse the direction on the App so all good. Although this all works up to a point I’m working on an improved approach so stay tuned for more updates . . !
I suppose you could calculate power from I^2.R if you assume the inverter load impedance presented to the solar panels remains constant, which for the most part it will be. Then adjust your calibration to get a known lower value if you have a comparison system to base it against.
@routercnc9517
9 ай бұрын
Interesting idea. That would avoid having to average out the string voltages on the PV array. Downside would be it be specific to a given inverter (unless they all use the same input components for the DC/DC converter), and as you say it would need be calibrated empirically by inspection of the readings Vs the known values on the inverter. But worth a look. I’m working on improving the other end of the system so I’ll put it on the list. Thanks for the idea.
@G6EJD
9 ай бұрын
@@routercnc9517 having designed inverters, you will find the input circuits present an impedance that is relatively constant so I think I.^2.R is worth a look. My iPhone misspelt / changed some words!
@routercnc9517
9 ай бұрын
OK thanks for the input. I’m working on a closed loop feedback for the current control rather than open loop. Getting there and showing some promise so when I’ve got that sorted out I’ll look at the input end. Thanks