Use of Synchronized Sampling in Fault Location ECEN Computer Relays Project #1 Presented by: Fahad Saleh Alismail UIN: Monday 03/03/2014

The Agenda Introduction The Basic concept of the Synchronized Sampling Algorithm Synchronized Sampling Based Fault Location (SSFL) The mathematical Model of SSFL The implementation of SSFL in the short line Model Advantages and Disadvantages of SSFL Conclusion

Introduction  Whenever a transmission line fault has occurred, it is very important to accurately locate the fault to isolate the fault and direct the maintenance crew promptly to reach the fault location and restore the line.  The conventional fault location algorithms use voltages and currents informations that are sampled only from one end of the line. (This technique has a problem with the accuracy)  After the adopting of microprocessors to the area of power system, along with the new communication channels such as GPS, Synchronized Sampling has become affordable.

Introduction  The synchronized sampling technique is demonstrated for the fault location applications.  The transmission line time domain model is used to derive the generic fault location equation and formulate the algorithm.  Samples of voltages and currents are measured synchronously from both ends of the examined line.

Introduction  Synchronization is achieved through utilizing the satellite communication signals delivered by the Global Positioning System (GPS).  Different configurations of transmission line models will be experimented to evaluate the performance of the proposed algorithm.  Several types of fault in different locations will be applied to verify the efficiency of the presented technique.

Synchronized Sampling Algorithm, How does it work? Fig. 1. Functional Block Diagram of a Synchronized Measurement System. Both (S/H) and (A/D) work at a time instant that is defend by Sampling Clock, which control the rate of sampling > 4khz

Synchronized Sampling Based Fault Location (SSFL) Fig. 2. Fault Location System.

The mathematical Model Fig. 3. Faulted Three Phase Transmission Line.

SSFL Implementation in the Short Line Model Short Line Application 161 kV power system and miles long

the Error (%) of the Short-Line Fault Location Algorithm for Different Fault Types Fault Type Error (%) of the short-line fault location algorithm Phase a to ground fault Location of Fault Incidence Angle (deg) R f =3Ω R f =50Ω Fault Type Error (%) of the short-line fault location algorithm Three-phase to ground fault Location of Fault Incidence Angle (deg) R f =3Ω R f =50Ω Fault Type Error (%) of the short-line fault location algorithm Phase b to phase c fault Location of Fault Incidence Angle (deg) R f =3Ω R f =50Ω Fault Type Error (%) of the short-line fault location algorithm Phase b to phase c to ground fault Location of Fault Incidence Angle (deg) R f =3Ω R f =50Ω

Advantages and Disadvantages of SSFL  Advantages of using SSFL:  The algorithm shows an excellent accuracy in determining the fault location regardless of the system operating conditions and constraints. This is because of the wide consideration of the line parameters, including the mutual coupling between parallel lines, during the fault location equation derivation.  The algorithm requires only the line model and the synchronous data in the line ends for the computation, so there is no need to know the fault impedance, so it can deal with the a time varying fault impedance cases as well.  SSFL shows better performance under power swing and out of step conditions compared to the distance relays.  SSFL is considered as fast algorithm which can locate the fault even before that fault is isolated by CB, it can operate with sampling frequencies down to 4 kHz and computes the fault location within one cycle of data.

Advantages and Disadvantages of SSFL  Weaknesses of using SSFL:  It involves extra equipment to receive synchronizing signals either from a GPS satellite or fiber optics communication systems, so it is higher in cost than other fault location techniques.  SSFL requires high capability processors to carry out the computations involved specially for long transmission line application. Since the derivatives in the fault location equation can be precisely calculated with a higher sampling frequency.  Synchronization errors due to response of a non-properly sized CT or VT, noise, sampling frequency etc.

Conclusion In this project, a synchronized sampling technique is demonstrated for the fault location applications. It has been addressed that the fault location scheme becomes more powerful and reliable when voltages and currents signals are taken simultaneously from the two ends of the line. Moreover, the studded algorithm shows an excellent results with an error that never reaches 0.75%, which makes it useful for different power system control and monitoring applications.

References [1]M. Kezunović, J. Mrkić, and B. Peruničić, "An accurate fault location algorithm using synchronized sampling," Electric Power Systems Research, vol. 29, pp , 5// [2]A. Gopalakrishnan, M. Kezunovic, S. M. McKenna, and D. M. Hamai, "Fault location using the distributed parameter transmission line model," Power Delivery, IEEE Transactions on, vol. 15, pp , [3]M. K. A. Gopalakrishnan, S.M. McKenna, D.M. Hamai, "Extension to Fault Location Algorithm Based on Synchronized Sampling," presented at the CIGRE Colloquium, SC 34, Florence, Italy, [4]M. Kezunovic and B. Perunicic, "Synchronized sampling improves fault location," Computer Applications in Power, IEEE, vol. 8, pp , [5]M. Kezunovic and B. Perunicic, "Automated transmission line fault analysis using synchronized sampling at two ends," Power Systems, IEEE Transactions on, vol. 11, pp , [6]Z. Nan and M. Kezunovic, "A study of synchronized sampling based fault location algorithm performance under power swing and out-of-step conditions," in Power Tech, 2005 IEEE Russia, 2005, pp [7]M. Kezunovic and M. Knezev, "Selection of optimal fault location algorithm," in Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008 IEEE, 2008, pp. 1-5.

References [8]G. Preston, Radojevic, x, Z. M., C. H. Kim, and V. Terzija, "New settings-free fault location algorithm based on synchronised sampling," Generation, Transmission & Distribution, IET, vol. 5, pp , [9]A. G. Phadke, B. Pickett, M. Adamiak, M. Begovic, G. Benmouyal, R. O. Burnett, Jr., et al., "Synchronized sampling and phasor measurements for relaying and control," Power Delivery, IEEE Transactions on, vol. 9, pp , [10]Z. Ce and M. Kezunovic, "Synchronized sampling uses for real-time monitoring and control," in North American Power Symposium (NAPS), 2009, 2009, pp [11]C. Yu, L. Dong, and X. Bingyin, "Wide-Area Traveling Wave Fault Location System Based on IEC61850," Smart Grid, IEEE Transactions on, vol. 4, pp , [12]M. Kezunovic, "Smart Fault Location for Smart Grids," Smart Grid, IEEE Transactions on, vol. 2, pp , [13]N. Zhang and M. Kezunovic, "Complete Fault Analysis for Long Transmission Line Using Synchronized Sampling," in Power Plants and Power Systems Control 2006, D. Westwick, Ed., ed Oxford: Elsevier Science Ltd, 2007, pp

Subtitle