Transmission line fault location utilizing sparse measurements

Project Summary Objective: Prompt and accurate location of faults in a transmission system can accelerate system restoration, reduce outage time and improve the system reliability. Diverse transmission line fault location algorithms have been proposed in the past depending on measurements available. Existing algorithms usually require measurements captured from buses of a faulted line. This proposal intends to investigate possible fault location approaches for transmission lines utilizing sparse voltage and/or current measurements from buses and branches that may be distant from the faulted line. Both single-circuit and double-circuit lines will be considered. Since meters may be capable of obtaining voltage and current phasors or magnitudes only, we will explore possibilities for fault location employing phasors or magnitudes alone such as voltage sags at sparse buses. Both synchronized and unsynchronized measurements will be exploited. Especially data from Phasor Measurement Units (PMU) will be fully taken advantage of. Intellectual Merit: This research project intends to investigate the appropriate estimation theories for transmission line fault location, aiming at making fundamental contributions to the areas of power system monitoring, protection and fault analysis. The proposed research would result in approaches for reliably estimating the fault location utilizing very sparse measurements. Accurate estimate of the fault location will greatly reduce the outage time and significantly enhance the system reliability. Specifically, the efforts will focus on the following tasks: 1. Investigate appropriate methodology for locating transmission line faults utilizing sparse voltage and/or current measurements, which could be synchronized or unsynchronized 2. Develop fault location algorithms for both single-circuit and double-circuit lines 3. Develop fault location methods by exploiting voltage and/or current magnitude 4. Derive efficient approach for building the bus impedance matrix with addition of the fictitious bus at the fault point, which can significantly facilitate short circuit studies Broader Impacts: This work will have broader impacts in several areas. First, the developed fault location approach would be able to accurately pinpoint the fault location by making the most of available sparse measurements, thus greatly improving the reliability of the power system, reducing the costs associated with the outage, and enhancing the welfare of the society. Second, the proposed method has the potential to be utilized for online protection purposes, and this could considerably improve distance protection accuracy employing local data. Third, results of this project will be utilized in the classroom to enrich the curriculum. The research results will be assimilated into the power system protection course the PI is developing at the University of Kentucky. The underrepresented students, especially women, African Americans and those from Appalachia will be encouraged and recruited to work on the project to give them more opportunities and increase their confidence in pursuing a bachelor, master or doctoral degree. Fourth, the project results will be promptly and broadly disseminated through PI's webpage, technical publication and presentations.