SolarInvert: Testing solar inverters with overload

06/05/2018 | Print view

A staff member of SolarInvert repairs the control electronics of an inverter. - © HS — © HS

A staff member of SolarInvert repairs the control electronics of an inverter.

SolarInvert from Germany test each of their inverters at 20 to 30 percent overload. The company is small and their small inverters work at very low system voltages and high currents.

Most manufacturers offer their solar inverters as multi-string units working at 1,000 volts. SolarInvert can handle 24 to 96 volts, without requiring a boost converter. The units can be switched in parallel and are particularly suitable for solar façades. Because of the lower voltage, these units can be more easily accessed.

Hook up storage batteries directly

Also, storage batteries can be hooked up directly. “Because the currents are so high, more copper goes into our units,” Tobias Schwartz, CEO of SolarInvert, states. “And because of the low voltage, the electronics can be very simple, requiring fewer components. Operating at a low voltage also has benefits when it comes to repairs.” SolarInvert has been building and repairing solar inverters for the last 20 years. About 15,000 units have been sold so far.

Regular check-ups and maintenance

Last year, 200 inverters needed repairs. “The more complicated the circuit boards are, the more likely are they to fail,” Tobias Schwartz judges. “If the inverter has a cooling fan, then that also requires maintenance. A key factor is whether the unit can become dirty in the course of operation. And that in turn strongly depends on the location.” SolarInvert make do without a cooling fan, the units are only cooled by passive means.

Regular check-ups required

Fan or no fan: Inverters, like everything else, require regular check-ups and maintenance. One easy test: Under normal circumstances, they should only be slightly warm to the touch while running. Faulty inverters switch off and are therefore cold.

Units with a transformer are more sluggish in heating up: The transformer takes time to become warm. “Units without transformers get hot faster,” Schwartz says. “Similar to the CPU of a computer. And that is also why such inverters tend to be equipped with an cooling fan.” (HS)

Stay informed, get our newsletter twice a week.
Register here: http://www.pveurope.eu/Newsletter