Wide-area Ethernet network configuration for system protection messaging

Faced with demands on its transmission grid from new generation providers, SCE is now deploying its Centralized Remedial Action Scheme (C-RAS) - among the largest wide-area control systems applied to an electric transmission grid anywhere. The C-RAS architecture is the prototype for future wide area monitoring, protection, automation, and control (WAMPAC) systems that collect data from across the grid to carry out the full range of utility transmission control functions, including those with high speed and mission-critical reliability. C-RAS uses Ethernet networking and IEC 61850 GOOSE messaging for flexibility, scalability, speed of operation, and inherent performance monitoring. Wide area application is beyond the original intended application of GOOSE, and requires special attention to the arrangement of the Ethernet network paths to assure fast, reliable, secure transmission. The paper has described how the communications infrastructure has been designed and configured to meet C-RAS requirements. Experience from C-RAS development may be helpful for other industry applications of IEC 61850 GOOSE messaging between sites connected by a WAN link. The first phase of C-RAS will be fully deployed in 2014. Over the years of C-RAS growth, ongoing relay development will bring implementations of new services using the protocol of IEC 61850-90-5, which is specifically designed for applications like C-RAS and can be incrementally phased into individual substations and communications links.