Solar Panels and DC Bus of Drives

AustralIan · Nov 1, 2016

Has anyone looked at/done any work with Solar Panels and batteries feeding the DC Bus directly? Wondering where to start.

I have equipment with a few VSDs (Total 50kW) that I would like to supply with solar panels. I have a big roof.

JesperMP · Nov 1, 2016

Some VFD manufacturers allows a socalled "common DC-bus".
I have no experience with it, but I would guess that the VFD has to "know" that it is having a common DC bus, otherwise it may trigger faults because the DC bus behaves "strangely".

Then you would be able to connect a DC voltage to the DC-Bus terminals of the VFD.
This will be a quite high voltage (for 400V AC, the DC voltage would have to be the peak 580V). So you need some kind of DC-DC booster.
I would guess that there are solutions that are available for this purpose. I am worried about the DC-DC boosting to such high voltages. Very dangerous ! I doubt that it is legal to DIY.

AustralIan · Nov 1, 2016

Definitely not a DIY project.

I was thinking maybe a PowerPack (https://www.tesla.com/en_GB/powerpack) or two, but didn't know if someone had already implemented something.

BryanG · Nov 1, 2016

I was buying an ABB Inverter and saw a reference to a Solar Pump version, a quick web search found this:

https://library.e.abb.com/public/de33478b2ec91d9048257ccf003986a7/EN_ACS355_N827_SUPPL_B_A4.pdf

GaryS · Nov 1, 2016

I know Yaskawa can do what you want to do. they can do a DC Buss to a VFD.
But a bigger problem is the voltage necessary to run the motors 250VDC in a lot for a solar panel.

Jeev · Nov 1, 2016

Most of the drives we deal with have DC Bus voltages in the order of 600-800V. Either way you do it; you'll be needing a solar charge and/or load controller that can handle that sort of voltage and whatever current load is required for your drive setup.

Off the top of my head both SEW and AB drives will do DC Bus supply.

DwSoFt · Nov 1, 2016

I have seen AB with a common DC bus between 8 vfd's. it was not solar supplied though, it just had a huge rectifier feeding the 8 "half" VFDs. the purpose was that they were high inertia loads (pumpjack), so when one was generating, it could be gobbled up by one that was consuming, and then excess would be sent to a DC Braking resistor.
Im kind of interested in wether a solar system could do this. it should be able to in theory if sized properly. id deff. want to talk to the manufacturer directly to consult on such an undertaking.

bitmonkey · Nov 2, 2016

I hope you have a big bank account as well! Have you priced solar panels and batteries?

AustralIan · Nov 2, 2016

It is an energy investment! Plus you help the environment and what not.

AustralIan · Nov 2, 2016

It seems most VSDs with a DC Bus are suitable for this application, it is just a matter of finding a solar installer that knows what to do with the charge controller side of things. I am tempted to go with Tesla just for the prestige, but any other ideas of who to look at?

Gene Bond · Nov 2, 2016

http://www.mesindy.com/Blinkless.html

This is the ultimate power control if you want to tie multiple sources together...

Solar Panels and DC Bus of Drives

AustralIan

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JesperMP

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AustralIan

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BryanG

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GaryS

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Jeev

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DwSoFt

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bitmonkey

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AustralIan

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AustralIan

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Gene Bond

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