SiC-Based Solid-State Fault Current Control System for Vulnerability Reduction of Power Distribution Networks

This STTR project seeks to develop high-voltage, high-performance Solid-State Fault Current Controller (SSFCC) technology utilizing Silicon Carbide (SiC) super gate-turn-off thyristors (SGTOs). Due to improved technical advantages, the proposed SSFCC technology will minimize fault-related power quality issues (i.e., voltage sags, oscillations, harmonics, etc.), improve network reliability (i.e., minimization of affected area), and allow for power re-routing in the event of a long-term or permanent fault. Presently, power interruption and quality issues cause economic losses to the nation, conservatively estimated to be over $100 Billion/year. It is estimated that this number will grow larger as the complexity of the power network increases. In order to support continuous economic growth through secure, affordable, and reliable energy, the United States Congress passed the Energy Policy Act of 2005 which mandates energy self-sufficiency by 2025. To achieve this, the delivery of electricity will need to expand, evolve, and become smarter, more flexible and more reliable while including new elements such as renewable energy (RE) sources and distributed energy (DG) sources. This suggest that the power network of the future will require more sophisticated and advanced protection devices such as the proposed SSFCC. As such, SSFCCs will become an integral part of smart distribution feeders under the so-call smart grid. Future distribution systems will have greater requirements for increased reliability and risk vulnerability reductions as electric loads become more sophisticated and less resistant to disturbances, even those of very short durations. The team has already proven the feasibility of the proposed concept by developing a low-power, low-voltage SiC-based SSFCC prototype. Research carried out during the Phase I portion of this STTR project demonstrated three key additional points that can be summarized as follows: a) system scalability (i.e., 4.16 kV to 13.8 kV SSFCC systems using 4.5 kV device technology), b) system functionality (i.e., fast and accurate fault current control) and c) system added value (i.e., improved power quality). For the Phase II portion of this STTR project, the team will focus on demonstrating the benefits of using SiC­based SSFCC device technology. The team will accomplish this by 1) extensively testing a single-phase 4160V-class SiC-based SSFCC hardware prototype available to this program, and 2) determining cost benefits associated with the unprecedented level of protection that this new SSFCC technology provides. In addition, during Phase II the team will also target several technical goals with the objective of developing a deep understanding of all benefits and capabilities associated with the mass deployment of SSFCC devices. This knowledge will be a key piece of information needed by utility companies and other users before SSFCC devices can be widely accepted. Commercial Applications and other Benefits as described by the awardee: Commercial applications include fault current and power flow controller for land and sea based distribution systems. Additional benefits include: minimization of affected areas, improved service quality, longer time between scheduled maintenance and longer service life of many distribution components such as transformers, cables, etc.