Spikes in production

warrenb

I have a Solis inverter and I get near realtime stats on a website for it. I have noticed that there appear to be spikes in production and wondered if anyone else got these. These spikes can jump up to 6kw production but only for a few minutes.


3046.00 Aug.19 08:09,2015
6544.00 Aug.19 08:14,2015
2119.00 Aug.19 08:19,2015


Thanks

zeupater

Hi

It's almost certainly a timing issue between the inverter writing a generation record to it's internal files and submitting a record to the website.

Very occasionally the inverter 'history' routine will write a record so close to the web submission routine run that it creates a temporary file contention issue resulting in the latest record not being picked up (no reading in a timeslice) and other-times, for exactly the same reason, it'll effectively submit/record the total for two time-slices as one thus creating a 'phantom' peak .... it happens quite often with automated data acquisition systems in industry, however, the solution of writing a routine to intercept & correct the issue usually lengthens the record lock period thus increasing the likelihood of a file/record contention condition occurring ....

The usual way of forwarding the generation to another system would be to submit a minimum of a 'Timestamp' and a 'RunningTotal', that way you have a degree of error mitigation for missing or double submission records, so there shouldn't be an anomaly between systems over time, although there could be for individual timeslices, or even in rare circumstances (power outages, clock/date changes etc) particular days.

HTH
Z

warrenb

Thanks for that great explanation, and as a system analyst one I can fully understand.

Anyone out there with a Solis inverter note that CT clamp monitors are incompatible with these inverters as they produce a lot of reactive power (transformerless) when in standby or low production.

I am now buying an Eco Eye PV as this has a voltage sensor so can detect when power is reactive.