use of synchronized sampling in fault location ecen 679 - computer relays project #1 presented by:...

Use of Synchronized Sampling in Fault Location

ECEN 679 - Computer Relays

Project #1

Presented by: Fahad Saleh Alismail

UIN:822008822

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

The voltage at the fault location can be expressed in terms of &:

Where, are the linear operators which depend on

the transmission line parameters.

Hence, we get the following equation:

Since, the hypothetical line is homogeneous:

(the Generic Fault Equation )

and are the measured values and and are the calculated values from the measured quantities and .

Fig. 3. Faulted Three Phase Transmission Line.

SSFL Implementation in the Short Line Model

Short Line Application161 kV power system and 13.35

miles long

Z1 Z3

Z2

Z23Z12

Z13

2

31

#1

#2

#3

m=a, b, c

the Error (%) of the Short-Line Fault Location Algorithm for Different Fault Types

FaultType

Error (%) of the short-line fault location algorithm

Phase a to ground fault

Location of Fault 0.1 0.5 0.8Incidence Angle (deg) 0 90 0 90 0 90

Rf=3Ω 0.4344 0.4346 0.2901 0.2093 0.0388 0.0390

Rf=50Ω 0.4576 0.4549 0.2237 0.2229 0.0464 0.0472

FaultType


Three-phaseto ground fault


Rf=3Ω 0.7084 0.7084 0.3658 0.3658 0.1066 0.1066

Rf=50Ω 0.7084 0.6991 0.3658 0.3612 0.1066 0.1052

FaultType


Phase b tophase c fault


Rf=3Ω 0.7075 0.7166 0.3658 0.3707 0.1075 0.1091

Rf=50Ω 0.7428 0.7283 0.3915 0.3855 0.1241 0.1262

FaultType


Phase b tophase c to ground fault


Rf=3Ω 0.5938 0.5912 0.3159 0.3143 0.0900 0.0885

Rf=50Ω 0.7036 0.7067 0.3635 0.3654 0.1060 0.1066

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. 161-169, 5// 1994.

[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. 1169-1174, 2000.

[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, 1999.

[4] M. Kezunovic and B. Perunicic, "Synchronized sampling improves fault location," Computer Applications in

Power, IEEE, vol. 8, pp. 30-33, 1995.

[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. 441-447, 1996.

[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. 1-7.

[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.

376-383, 2011.

[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. 442-452, 1994.

[10] Z. Ce and M. Kezunovic, "Synchronized sampling uses for real-time monitoring and control," in

North American Power Symposium (NAPS), 2009, 2009, pp. 1-6.

[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. 1207-1215, 2013.

[12] M. Kezunovic, "Smart Fault Location for Smart Grids," Smart Grid, IEEE Transactions on, vol. 2,

pp. 11-22, 2011.

[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. 137-142.

Subtitle

use of synchronized sampling in fault location ecen 679 - computer relays project #1 presented by:...

Documents