Hi, we have one of the 3 phase stackable battery systems and noticed a big dip in grid voltage yesterday. This is within the allowable range for 3 phase but I was interested to try and understand why this large drop could have happened. Any ideas?
Grid voltage variation would be a question for your DNO, and they’d answer ‘it’s within allowable tolerance’
The supply voltage goes up and down all the time with ever changing supply and demand. It could be that a large industrial plant “nearby” has turned on its equipment or a wind farm has shutdown a turbine for maintenance, or lots of other reasons.
I don’t have 3 phase but I’d imagine that since you are getting all 3 phases blended together, any grid voltage variation that you get on a normal single phase is amplified by 3 so you see bigger variations
My own grid supply dropped 20V last night in the space of about 9 minutes
If you search your local DNO's website you'll probably find a power cut somewhere around that time which, depending on where it was, may have disconnected local generation and/or routes, which in turn puts more strain on remaining assets to fill (which would pull voltage down)
It being for 2 or so hours before going back up to the "normal" level for the day is about right for the DNO to get out to whatever it is & either fix or reconfigure local supplies to get voltages back to normal.
Thanks chaps, that makes sense, I guess until I got the system I never realised the grid voltage fluctuated like that.