Development of Resistive Fault Current Limiters Based on YBCO Coated Conductors

All over the world there is a growing need for current limiting devices in electrical networks with steadily increasing power demands and fault currents. Production of YBCO coated conductors (CCs) paves the way for the economic viability of superconducting fault current limiters (FCLs) both in power distribution and transmission networks. In a cooperation between AMSC and Siemens the limiting capability of YBCO CCs has been investigated and was demonstrated in a successful laboratory test of a 2.2 MVA medium voltage FCL. This device is based on bifilar coils as switching elements and corresponds to one phase of a 3-phase FCL designed for the 13 kV-class distribution voltage level. In more than 40 switching tests at voltages up to 7.7 kV the device showed excellent limiting performance. Presently this cooperation has entered a new DOE funded joint project that encompasses the design, construction and test of a 115 kV FCL for power transmission within a time frame of 4-5 years and additional partners. AMSC as the project leader is responsible for wire manufacturing, system integration and cryogenics. Siemens´ main task is switching modules development, Nexans contributes the high voltage terminations and Los Alamos National Lab investigates AC losses. Installation and testing are planned for a Southern California Edison substation. A project overview and progress under the first phase will be reported.