1. Use of Phasors for Fault Location Presenter: Armando Maldonado Instructor: Dr. Mladen Kezunovic Ph.D. Course: ECEN 679 Computer Relays

2. Single Ended Protection Relay Protection, voltage and current inputs at one end of transmission line. Fault type must be determined prior to fault location algorithm Algorithm calculates inductance from relay location to fault Fault Impedance = errors Load flow = errors Zero Sequence mutual coupling = errors

3. Single Ended Protection

4. Voltage and current phasors determined by fault type to properly solve for “n” AG Faults LL Faults ZR1 = positive sequence impedance of the transmission line ZR0 = zero sequence impedance of the transmission line K0 = ratio of zero sequence impedance to positive sequence impedance of the line.

5. Two Ended Protection

6. Negative Sequence Voltage Magnitudes Voltage magnitudes indicate faulted line section

7. Two Ended Protection

8. Comparisons Single Ended Fault Location Pros Only needs access to 1 terminal’s voltage and current values No communication to other terminals Cons Nonhomogeneous systems Subject to errors from load flow mutual coupling Fault location approximation accuracy Two Ended Fault Location Pros Algorithm not affected by fault resistance, load or zero sequence mutual coupling. Accurate fault locations Nonhomogeneous systems Cons Communication to other terminals Needs accurate time stamps Data at both ends gathered at one location for analysis

9. References J.M. Kennedy, General Electric, “Evaluation of a Phasor-Based Fault Location Algorithm,”GE Protection and Controls, GER-3963. Yanfeng Gong, Mangapathirao Mynam, Armando Guzmin and Gabriel Benmouyal, Schweitzer Engineering Laboratories, “Automated Fault Location System for Nonhomogeneous Transmission Networks,” Boris Schulim, Orange and Rockland Utilities, 2012. Abdolhamid Rahideh, Mohsen Gitizadeh, Sirus Mohammadi, “A Fault Location Technique for Transmission Lines Using Phasor Measurements,” International Journal of Engineering and Advance Technology (IJEAT), ISSN: 2249-8958, Volume-2,Issue-1, October 2013 IEEE Guide for Determining Fault Location on AC Transmission and Distribution Lines, IEEE Standard C37.114, 2004. S.M. Brahma, “New Fault Location Method for a Single Multi-Terminal Transmission Line Using Synchronized Phasor Measurements,” IEEE Trans. Power Delivery, Vol. 21-3, pp. 1148-1153, July 2006.

10. Thank you Questions?