ADAPTIVE PMU-BASED FAULT LOCATION METHOD FOR SERIES-COMPENSATED LINES

摘要

The adaptive phasor measurement unit (PMU)-based series-compensated line (SCL) fault location method uses three different sets of pre-fault voltage and current phasor measurements at both terminals of the SCL. The three sets of local PMU measurements at each terminal are used for online calculation of a respective Thevenin Equivalent (TE). This enables representation of the power system pre-fault network with a reduced two-terminal equivalent system. The PMU measurements are also utilized for online calculation of the SCL parameters. This non-iterative method does not need knowledge of a time elapsed for the wave propagation from a fault point to a sending end and a receiving end. Two subroutines SA and SB are used for locating faults. A selection procedure is applied for indicating the valid subroutine and, hence, the actual fault location.

主权项

1. An adaptive phasor measurement unit (PMU)-based fault location method for a series-compensated line (SCL), comprising the steps of:
acquiring three independent sets of pre-fault voltage and current (VA, IA) phasor measurements at a first terminal of a power system network; acquiring three independent sets of pre-fault voltage and current (VB, IB) phasor measurements at a second terminal of said power system network, the three independent sets of PMU pre-fault phasor measurements at the first terminal (VA, IA) and the three independent sets of PMU pre-fault phasor measurements at the second terminal (VB, IB) having a common time reference; determining the power system network's Thevenin Equivalent (TE) at the first terminal from the first terminal pre-fault phasor measurements; determining the power system network's Thevenin Equivalent (TE) at the second terminal from the second terminal pre-fault phasor measurements; determining line parameters and a voltage drop of a series compensator (SC) in the power system network using a least squares determination applied to each set of the pre-fault phasor measurements; performing a symmetrical transformation of phasor quantities to obtain the corresponding positive, negative and zero sequence quantities; determining fault distances of a first fault distance based on the symmetrical transformation using a fault loop on a first subroutine network (SA) comprised of a line that includes the first terminal and the SC and of a second fault distance based on the symmetrical transformation using a fault loop on a second subroutine network (SB) comprised of a line that includes the second terminal and the SC, for each subroutine network the total line length being the distance between the first terminal and the second terminal; selecting as a valid subroutine network one from the group consisting of the first subroutine network (SA) corresponding to the first determined fault distance and a second subroutine network (SB) corresponding to the second determined fault distance; and determining an actual fault location fault distance by a fault loop on the selected one of the first subroutine network (SA) or the second subroutine network (SB) as the valid subroutine network.