Technical Note #2 – Effect of AC Loads on Solar Generators

How can we prevent high failure rates of solar generators caused by AC loads?

Issue 02 of our Technical Note is out! Our paper on the Effect of AC Loads on Solar Generators offers essential testing and recommendations for solar developers.

Key failures of solar systems often result from load-related issues, which we examined through high-resolution measurements of 20 common AC loads in Nigeria and their replication in our Berlin office. Our research shows that load behavior can vary significantly from power ratings, that 4 out of 5 inverters fail under certain stresses, and that some load scenarios pose long-term risks for inverter power electronics.

Key findings include:

Simple adoption in the gate drive circuitry can prevent fatal shootthroughs.
An adapted inrush current limiter can lower failure rates for 75% of the tested inverters while at the same time allowing for 20% more loads being successfully powered.

Our Recommendations to manufacturers:

During your next design iteration, put extra attention on

your overload protection – so it properly reacts to current transients;
your output voltage control speed – shouldn’t be slower than 200us;
adding an internal current limitation, if not already present;
your current gate drive circuit – a 2 cent component can save your product;
your DC link protection circuit.

Our Recommendations for distributors:

Consider adding inrush current limiters to your portfolio – it can boost customer satisfaction and lower your failure rate!
Do proper load assessments and be careful with nominal load ratings!

➡️ Please download the Technical Note Issue 02 here.

➡️ Want to learn more about preventing failure rates in solar generator design? Watch our Webinar here.

➡️ Missed Issue 01 of our Technical Note? Review it here.

Please feel free to contact us for more info!