In this special edition of Contractors Corner, solar inverter manufacturer SMA America talks about the challenges of traditional PV system optimization, and the new solutions available from the company. Listen to the full episode here or on your favorite podcast app.
Solarman says
I find it interesting the mention of NEC 2017 and RSD modules attached to panels on the roof. How does one add Communications and RSD to a TESLA roof tile solar PV solution? Talk of the SMA “advantage” of going from “60,000” devices to “30,000” devices and yet adding communications into a hostile operating environment may be “necessary” by code, but can also fault out and create system failures on a random and difficult to troubleshoot event. I find the concept of troubleshooting and “decision” trees as part of the monitoring of the system of great value. Just 15 years ago, one was often “scheduled” for a site callout on an “intermittent” fault problem, sometimes with NO resolution with several service calls. My experience was a quick visual inspection of system wiring from roof to inverter to C.B. panel. IF the inverter had a fault code(s) call the manufacturer and give them the code(s), be sure to tell them you’ve (reset) the system probably more than once already. Usually the service tech. opens an RMA ticket, a new or refurbished inverter is sent out and one can then, find a local solar PV company or electrician to swap out the inverter or do it yourself, not recommended by many. I have found over the years, that most grid tied inverters fail when the internal cooling fan(s), many who claim they are sealed, gum up and the inverter fails under temperature shutdown faults. Sometimes taking a logic power supply regulator with it.
Higher power handling inverter final drive components, using maybe SiC switching transistors, designing heat sinking into a system that the cooling fan not only has a “monitoring” circuit but the fan is designed for a quick disconnect and replacement that can be done in minutes instead of hours. Modularity in command and control modules makes on site field service more effective and reliable in the long run. If one was to take ‘any inverter’ from any manufacturer that failed. You would find heat soak and component fail from electrolytic capacitors, cooling fan(s), and operating power supply voltages out or out of specifications. All heat related, so, money should be spent by the manufacturer to make the 20 year heat removal system for the inverter first of all. Component (specifications) are next, some components have a “part number” or circuit manufacturing type, then a “temperature” code often defined as an ‘A’, ‘B’, or ‘C’ after the part number. On IC product lines today, thousands of circuits roll off the line at pennies per IC package. Components like electrolytic capacitors come in different temperature operating ranges. I’d say for something as a D.C. to A.C. power inverter, all electrolytic capacitors should be at least 105 degrees C rated. Cheaping out on any of these components makes for a failure waiting to happen. Technology is at the point, that $10 more in higher temperature and tolerance components makes for a more robust and reliable product. Careful design and component layout and another $10 can make the 20 year inverter every body wants.