Easy 3-phase power ?

[gerry maddenParticipant @gerrymadden53711]

It would seem that some solar power inverters now have the facility to produce 3-phase power (in addition to single phase) for fast charging of electric cars. The energy cam come either from battery storage or direct from the panels. This could become increasingly popular for obvious reasons.

May be this could be a 3ph source for our workshops too ?

Does anyone have any direct experience of this technology as it may be of interest to me ?

Gerry

 

[Clive FosterParticipant @clivefoster55965]

Google is your friend here. Searching 3 phase solar panels brings up a fair bit of useful information.

It seems that you need a three phase supply from the electricity company to make it practical. Systems with battery back ump seem to start at around £10,000 for 7.5 kW of panels and a 5 kWh battery. It doesn’t look as if the battery could be charged via a single phase when the stored solar power runs out.

there are mentions of something called vector Phase Monitoring which initially looks as if you could have a single phase incomer from the utility supply. But in practice it an appears to be more about balancing things out when you may be exporting power on one or two phases and consuming power on one or two. Presumably when you have something like three phase workshop with officers running off one of the passes so unbalancing things.

There are inverter/charger clusters offered for turning 48 V DC into three phase using one inverter per phase. It’s not clear whether you need to use all three to charge the battery system or whether one could do it on its own operating as a single phase system. My impression is that the kit is out there to run a three phase shop from a battery back up but it doesn’t appear that you can get a package to charge the battery via single phase so you have a three phase supply for the workshop. I suspect that by the time you have got all the bits its not going to be cost effective compared to a rotary converter, one of Drives Direct “Plug and Play Whole Workshop” set ups or simply using one of the import “380 V nominal” single to three phase inverters for each machine.

Clive

 

[Robert Atkinson 2Participant @robertatkinson2]

They do indeed make such units. I have had experience using them including to drive 3 phase motors.
The inverters were quality Victron units. They have quite a a good overload rating, but even when de-rated they had trouble starting large 3 phase motors. To make them work we had to add a VFD with a slow ramp-up between the inverter and motor.
Other units may be different but generally these inverters are more expensive than VFDs so unless you were already considering solar power with storage I don’t think they are a viable solution.

Robert.

[not done it yetParticipant @notdoneityet]

I find adding about 175 miles of range overnight, on a suitable EV tariff, (5h with a 7kW charger, is generally more than adequate for my needs.

I’ll retain VFDs for running my workshop machines.  They seem simple enough.

[gerry maddenParticipant @gerrymadden53711]

Thanks Robert for your insight. I already have a 7.5Kw of solar panels and two inverters, but no battery.

My system is 11 years old and my thinking was that if the inverters begin to degrade, perhaps I could replace them with a single plus 3ph output type. Of course I would have to include a battery or the 3ph would only be available when the sun shines.  Unfortunately my inverters are showing no signs of deterioration so far, so I’m not in a hurry. And time should help bring the prices down too.

Gerry

 

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