Upgrade for solar generation

Paul Boughton

Three solar power stations in Australia’s Northern Territory are benefiting from the use of Semikron’s SKiiP intelligent power modules (IPMs).

Improvements in photovoltaic (PV) technology have resulted in increased power output from the stations’ arrays. This additional power has been easily handled by the systems’ inverters, by means of a straightforward upgrade of the SKiiP modules.

Until recently, the solar power stations used a total of 30 14m-wide parabolic mirrors to focus the sun’s energy onto panels of silicon PV cells. This allowed the three stations to generate a total of 720kW, allowing local communities to switch off their costly diesel generators. This had been calculated to save 420,000 litres of diesel oil and 1550 tonnes of greenhouse emissions in a year.

The stations’ generating capacity was recently increased from 24kW per generator to 35kW by simply replacing the PV cells with new technology – water-cooled, germanium-based multijunction PV cells that offer an industry-leading 30 percent efficiency. Output of the dishes is paired, delivering 260VDC into inverters using water-cooled 600V SKiiP power stages. By upgrading the SKiiP modules, it was a simple matter to upgrade the inverters to handle the increased power from the generators. A new 154MW station being planned for the state of Victoria has a target efficiency of 40 percent. This will require voltages to be increased to a more efficient 600-700VDC, using 1200V IGBT chips in the inverters.

SKiiP integrates perfectly-matched cooling, gate driver, current sensors and protective functions. High load and temperature cycling capability is ensured with the patented SKiiP pressure contact technology. With power handling into the MW range, this IGBT-based subsystem offers the highest power handling capability of any IPM on the market.



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