Transcript ECEN 679 Project 1 Topic 22: Fault Location

ECEN 679 Project 1
Topic 22: Fault Location Using
Synchronized Phasors
Po-Chen Chen
Instructor: Dr. M. Kezunovic
Mar. 3, 2014
Reference
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C.-S. Yu, C.-W. Liu, and J.-A Jiang, “A new fault location algorithm for series
compensated lines using synchronized phasor measurements”, IEEE/PES Summer Meeting,
vol. 3, pp. 1350 – 1354, Jul. 2000.
S. M. Brahma, “New Fault Location Method for a Single Multiterminal Transmission Line
Using Synchronized Phasor Measurements,” IEEE Trans. Power Del., vol. 21, no. 3, pp.
1148-1153, Jul. 2006.
S. M. Brahma, “Iterative Fault Location Scheme for a Transmission Line Using
Synchronized Phasor Measurements,” Int. J. of Emerging Electric Power Syst., vol. 8, no. 6,
Nov. 2007.
A. T. Johns and S. Jamali, “Accurate fault location technique for power transmission lines,”
Proc. Inst. Elect. Eng. C, vol. 137, no. 6, pp. 395-402, Nov. 1990.
J.-A. Jiang, et al., “An adaptive PMU based fault detection/location technique for
transmission lines-I. Theory and algorithms,” IEEE Trans. Power Del., vol. 15, no. 2, pp.
486-493, Apr. 2000.
Implementation Requirements [1]-[5]
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Synchronized voltage and current phasors (post-fault) from all the
terminals of the transmission line are needed.
DFT to extract phasors from voltage and current samples using PMU.
GPS Common Time Reference using GPS receiver for all terminals.
Communication network.
Possible Errors
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Synchronization Error (GPS time clock).
Phasor Calculation Error.
Modeling and Parameter Error (line asymmetry, distributed parameters,
length of line, the setting errors of data-processing units , etc).
Nonlinear characteristics of CT and CCVT itself
One Phase Example: Fundamental
Frequency Model [5]
where
and
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Extended for Three-Phase Line
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The vector of the three phase voltages and currents, can be written as
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If the line is perfectly transposed, the three phase system can be re-written
into positive, negative, and zero sequences. The equations of positive
sequence is just like (1) and (2). The equations of negative and zero
sequence voltages and currents can also be applied and the number of
equations will more than the number of unknowns.
Extended for Three-Phase Line
(Cont.)
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If the line is NOT perfectly transposed, the the theory of natural modes and
matrix function will be applied.
For two terminal TLs, non-iterative algorithm can be applied [4]. For multiterminal TLs, iterative algorithm can be applied [1], [2].
Advantages vs. Disadvantages
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The method is NOT sensitive to fault type, source impedance variation, or
fault resistance. Therefore, the method will not suffer from the estimation
errors from these quantities.
Comparing to algorithms using only one-ended phasor measurements, the
computational burden is less. Enough data will create the redundancy (i.e.
more equations than unknowns). However, the cost of implementation will
be increased.
Requirements of communication path and synchronization of the phasors
will increase the cost of implementation (compared to algorithms using
unsynchronized phasors). If the synchronization has error involved, then the
fault may not be located properly.