The installed photovoltaic capacity is growing rapidly worldwide. Photovoltaic systems with a total output of around 600GW now supply clean and cost-effective electricity – replacing around 600 medium-sized coal-fired power plants. SMA Solar Technology AG and Infineon Technologies AG support this growth trend with the latest generation of innovative silicon carbide (SiC)-based solar inverters. The new semiconductor material reduces the system costs for inverters and increases their efficiency. The production costs for solar power are thus further reduced.
With the Sunny Highpower PEAK3 from SMA, available since 2019, decentralized photovoltaic power plants can be planned flexibly and efficiently up to the megawatt range. The basis for this is the compact design for 1500Vdc, which delivers an output of 150kW per unit.
This is made possible by SiC technology from Infineon: Six power modules of the type CoolSiC™ EasyPACK™ 2B and 36 gate drivers of the EiceDRIVER™ family 1ED20 convert the direct current generated by the solar cells into grid-compatible alternating current – with an efficiency of over 99 percent.
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Silicon carbide offers advantages for the overall system
“Silicon carbide enables us to build the inverters compact, powerful and reliable,” said Sven Bremicker, Head of Technology Development Center at SMA. “In the Sunny Highpower PEAK3, the CoolSiC modules almost double the specific output from 0.97 to 1.76 kW/kg. Due to the compact design, the inverters are much easier to transport and much faster to install.”
The advantages of a decentralized plant layout can thus be combined with those for central inverters. Expansions are easily possible even after the photovoltaic power plant has been commissioned.
Rapid development of customized modules
Infineon has developed a customer-specific solution for SMA that includes both a classic TRENCHSTOP™IGBT and a CoolSiC™ MOSFET with body diode. The ANPC (Active Neutral-Point Clamped) topology allows system voltages up to 1500 V maximum to be switched with switches designed for 1200 V. The topology thus uses the advantages of SiC, although only some of the switches in the EasyPACK module are based on it. Overall, the use of SiC reduces the complexity in the inverter. This not only increases efficiency, but also makes the system easier to maintain and extends its service life.
“SiC-based power semiconductors are more expensive than silicon solutions,” said Dr. Peter Wawer, President of the Industrial Power Control Division of Infineon. “But thanks to the electrical properties of the material, this is more than offset at system level. Higher switching speeds and efficiency allow transformers, capacitors, heat sinks and ultimately packages to be smaller – and thus save system costs. We are very proud to have convinced with SMA the European market leader in photovoltaic inverters of the advantages and to support volume production with our innovative SiC products.”
“Not only photovoltaic systems profit from these advantages. Demand for SiC-based solutions from Infineon is also growing in other industrial sectors and for applications such as uninterruptible power supply and charging infrastructure for electric vehicles,” concluded Dr. Wawer.