Silicon carbide inverters can open medium-voltage grids for solar installs

Jan 26, 2021 07:33 PM ET
  • A research project has created a silicon carbide inverter with the ability of allowing large-scale solar systems to connect straight to medium-voltage grids without the need of a transformer.
Silicon carbide inverters can open medium-voltage grids for solar installs
Image: Fraunhofer ISE

The project, led by scientists at the Fraunhofer Institute for Solar Energy Systems ISE, has shown making use of silicon carbide (SiC) transistors in a small inverter, positioning countless benefits to both solar arrays and also grids in general.

Solar systems are predominantly connected to low-voltage grids, yet need coupling with 50Hz transformers to link to medium-voltage grids. Enabling their link to medium-voltage grids straight would open up a multitude of new possibilities as well as benefits for solar, Fraunhofer ISE stated.

The 'SiC-MSBat-- medium-voltage inverters with high-voltage SiC power modules for large-scale storage and also system-serving distribution grids' project saw scientists at Fraunhofer ISE work together with other partners to produce a highly portable inverter with the ability of directly feeding electrical power into the medium-voltage grid, as well as various other tasks in assistance grids.

Fraunhofer ISE stated making use of brand-new types of SiC transistors supplied extremely high blocking voltages, making it feasible to attach inverters using them directly to the medium-voltage grid, while additionally achieving significantly higher power densities than standard inverter designs.

The project saw the advancement of a 250kW inverter pile for feeding right into 3kV AC grids. Novel 3.3 kV SiC transistors were utilized in the design of the inverter stack, assuring lower power losses which, subsequently, enabled the inverter pile to operate with a switching frequency of 16kHz, around 10-times greater than changing regularities feasible utilizing other silicon transistors.

The inverter stack was then evaluated in Fraunhofer ISE's labs in Germany and demonstrated an effectiveness rate of 98.4% at its ranked power.

Fraunhofer ISE claimed the style of the device would enable modular interconnection of many inverter heaps to attain an end output approximately a number of megawatts, making them optimal for usage in utility-scale planetary systems.

Additionally, its portable design-- taking about 40% of the size of business inverter systems of the very same voltage class-- would certainly likewise permit systems to be deployed in extra inner-city areas where there is less available space, the study institute stated.

"With the 1500V PV innovation that has been offered for a couple of years, the low-voltage directive is already being completely exploited. The following step right here will be the transition to feed-in at medium-voltage level, which will bring additional potential for cost savings as well as renovations in the system principle of PV nuclear power plant," Andreas Hensel, that head's up Fraunhofer ISE's tool voltage power electronics team, claimed.

The project was moneyed by the German Federal Ministry for Economic Affairs as well as Energy, and also Fraunhofer ISE's companions in the project included Semikron Elektronik and STS Spezial-Transformatoren Stokach.