Improving transmission system resilience using an automation controller and Distributed Resources

As the transmission network has evolved over time, it has been operated closer to its limits and as a result lacks the ability to handle severe contingencies such as extreme weather, natural disasters, major generation failure, loss of transmission lines, or cyber-attacks. Depending on the timing of the event, these conditions could lead to cascading problems which can bring down an area larger than that directly affected by the event if they are not handled properly. Recent technological advancements in lower cost communication and control plus the increased use of distributed generation, gives an opportunity to break the transmission network into independent networks supplying local critical loads beyond the break points used by regional transmission operators. This paper demonstrates the concept with a relatively simple transmission system model and utilizes a commercial automation controller to partition the system. The local generators are able to supply the local critical loads. An algorithm is proposed to detect the abnormal situations and to isolate the system into independent networks. The isolated systems can supply the local critical loads under stable operating conditions following generator shedding or shedding of less critical loads. The entire system is modeled in a Real Time Digital Simulator (RTDS) along with an automation controller which communicates with model using the IEC 61850 standard protocol. The entire operation can be monitored and controlled with the help of a Human Machine Interface developed for the project.