A Missing Data Tolerant Wide-Area Back-Up Protection Scheme for Transmission Network

The proposed scheme develops a missing data tolerant wide area back-up protection scheme for power transmission network with fewer PMUs. The scheme assumes division of power system into different coherent groups. The fault detection index (FDI) is used to detect a fault in the system network using active power transfer and angular difference between voltages of connected areas or summation of negative and zero sequence current components in each area. The faulted area is then identified by change in area-current (CAC) using current contribution towards each area and finally, the faulted line is identified for the respective faulted area using distance to fault (DF) index. The scheme is extensively tested on a New-England 39-bus system for several fault and stressed scenarios considering all PMU data available and PMU data loss at some of the buses. For this, the PMUs are deployed at less than half number of system buses. The maximum response time of the proposed scheme is approximately 260 ms which is well within the third zone operation time of distance relays for back-up protection. The test results including the comparative assessment with existing schemes indicate that the proposed scheme can be a potential candidate for enhancing the performance of the wide-area back-up protection in the transmission network.