Solar Spotlight: Sungrow increases the power of possibilities for string inverters

By Billy Ludt | August 30, 2023

The inverter is a crucial component on a solar project because it converts the power generated by PV modules into usable electricity. Daniel Friberg, director of product and engineering at inverter manufacturer Sungrow, shares some details on the operations, hardware compatibility and environmental readiness of Sungrow’s SG350 line of string inverters.

Below is an excerpt of Sungrow’s Solar Spotlight podcast with Solar Power World, but be sure to listen to the full episode on your favorite podcast app.

Since the inverter market is so saturated, what makes this inverter stand out in comparison to other strings on the market?

Daniel Friberg, director of product and engineering at Sungrow.

It’s one of the largest ones available. It’s up to 350 kW, which is a large string inverter. I’m not aware of there are actually any larger string inverters on the market. Second, is that Sungrow can provide a fairly complete package where we basically provide not just the string inverter, but we also provide the switchgear and the transformation of the power from the inverter through the switchgear up to medium voltage level. Basically, we provide what we call the medium voltage switchgear skid, which includes a pad-mount transformer and power distribution for up to 14 of the SG350 inverters, so it’s a good complement.

As inverter-to-panel sizing is important to obtain maximum efficiency, can you explain some of the benefits of this inverter’s compatibility with wider PV modules?

When we designed this inverter, we looked at where we are and where we’re going, and the most typical PV panel has been these 180 cm (70 in.) type panels that typically string inverters typically have a maximum input of 15 amps or below. And that’s what most traditional string inverters can handle. But we have made two versions of our inverter, so we can certainly do that. We have a version like that with up to 32 string inputs. But we also looked at the future and what’s coming more and more are the larger 210 cm (82 in.), which we’re reaching power ranges well about 600 W, and with those panels, we’re going to require higher current levels at the inputs, so “Version A” is a 15-amp input and “Version B,” which we also sell, is a 20-amp input.

Now that climate change is rapidly affecting different environmental conditions, products need to be even more protected. How does this product perform in different environmental conditions?

We have looked at a severe type of environment and these also sit out in deserts and storms and things like that. So, we are providing a total NEMA 4X enclosed product. There is no exchange of any air from internal components to external components. It’s completely passive cooling from a heatsink type solution external to all the sensitive components.

What features does this inverter have which may further improve grid stability?

One of the important features that we see, especially as these are being deployed further and further out in remote areas, is the ability to keep the grid stable even if you have a very low short circuit ratio on the grid. So short circuit ratio (SCR) basically means that you can push and push and pull the grid very easily if you apply power to it, such as a generator, which in this case the PV inverter would be.

PID is a threat to many projects, but how does your anti-PID function differ from other string inverters?

PID, or potential induced degradation, that is something we see in systems with floating PV panels, where you may have an offset between the positive to ground and negative to ground polarity. In particular, thin-film solar panels are sensitive to this. So, it’s important to be able to offer this kind of feature.

This podcast is sponsored by Sungrow