SiC for Energy Applications at Darnell’s Energy Summit

Delegates to the 2014 edition of Darnell's Energy Summit received an update on the progress of developing "Silicon Carbide Power Electronics for Energy Applications: Perspectives, Targets, and the path to Applications through European Union SPEED Project," during a plenary presentation by Dr. Daniel Fernández, CTO of INAEL Electrical Systems and Coordinator of Project SPEED. The goal of Project SPEED is the development of SiC technology up to a level in which reliable high-voltage SiC devices can be built as basis for inverters, high-voltage switches, solid state transformers, and so on.

“SPEED aims at a breakthrough in SiC technology along the whole supply chain including: Growth of high-quality SiC substrates and epitaxial-layers; Fabrication of power devices in the 1.7kV / 10kV range; Packaging and reliability; and SiC-based highly efficient power conversion cells, Dr. Fernández stated. “Targets applications are in the energy industry including generation and transmission and distribution. No automotive, lightning, or traction are targeted by Project SPEED. The Project targets real-life applications and field-tests in close cooperation with manufacturers of HV devices and a major electrical utility,” he continued.

“Specific activities being pursued by Project SPEED include development of suitable SiC substrates, epitaxial-layers, and HV devices developed and implemented in two demonstrators: A cost-efficient solid-state transformer to support advanced grid smartness and power quality, and a wind-turbine specific power converter with improved capabilities for generating ac and dc power,” Dr. Fernández informed the DES ’14 delegates.

While the precise design of the solid-state transformer is still to be defined, Dr. Fernández was able to share some of the block-diagram concepts under consideration, including: the solid-state transformer (SST) will be a bi-directional switching power converter operating at 50kHz and handling both 13.8kV three-phase 60Hz power on one side and 480V three-phase 60Hz power on the other side.

The 13.8kV side of the power converter (SST) is expected to combine a 3kHz rectifier section using 15kV hard-switched SiC IGBTs feeding onto a 20kV bus followed by a 50kHz switching section using soft-switched 15kV SiC IGBTs. The 480V side of the SST is expected to consist of a 17kHz inverter using hard-switched 1.2kV SiC DMOS FETs feeding onto a 800V bus followed by a 50kHz switching section using soft-switched 1.2kV SiC DMOS FETs.

“The resulting solid-state transformer is expected to be the core of the future Intelligent Distribution Substation, that will integrate demand-side control distributed renewable generation, and storage,” Dr. Fernández concluded.