3 research outputs found
Source Location of Forced Oscillations Using Synchrophasor and SCADA Data
Recent advances in synchrophasor based oscillation monitoring algorithms have allowed engineers to detect oscillation issues that may have previously gone undetected. Although such an oscillation can be flagged and its oscillation shape can indicate the general vicinity of its source, low number of synchrophasors means that a specific generator or load that is the root cause of an oscillation cannot easily be pinpointed. Fortunately, SCADA serves as a much more readily available telemetered source of data if only at a relatively low sampling rate of 1 sample every 1 to 10 seconds. This paper shows that it is possible to combine synchrophasor and SCADA data for effective source location of forced oscillations. For multiple recent oscillation events, the proposed automatic methods were successful in correct identification of the oscillation source which was confirmed in each case by discussion with respective generation plant owners
Using Passivity Theory to Interpret the Dissipating Energy Flow Method
Despite wide-scale deployment of phasor measurement unit technology, locating
the sources of low frequency forced oscillations in power systems is still an
open research topic. The dissipating energy flow method is one source location
technique which has performed remarkably well in both simulation and real time
application at ISO New England. The method has several deficiencies, though,
which are still poorly understood. This paper borrows the concepts of passivity
and positive realness from the controls literature in order to interpret the
dissipating energy flow method, pinpoint the reasons for its deficiencies, and
set up a framework for improving the method. The theorems presented in this
paper are then tested via simulation on a simple infinite bus power system
model.Comment: Submitted to PESGM1
Using Effective Generator Impedance for Forced Oscillation Source Location
Locating the sources of forced low-frequency oscillations in power systems is
an important problem. A number of proposed methods demonstrate their practical
usefulness, but many of them rely on strong modeling assumptions and provide
poor performance in certain cases for reasons still not well understood. This
paper proposes a systematic method for locating the source of a forced
oscillation by considering a generator's response to fluctuations of its
terminal voltages and currents. It is shown that a generator can be represented
as an effective admittance matrix with respect to low-frequency oscillations,
and an explicit form for this matrix, for various generator models, is derived.
Furthermore, it is shown that a source generator, in addition to its effective
admittance, is characterized by the presence of an effective current source
thus giving a natural qualitative distinction between source and nonsource
generators. Detailed descriptions are given of a source detection procedure
based on this developed representation, and the method's effectiveness is
confirmed by simulations on the recommended testbeds (eg. WECC 179-bus system).
This method is free of strong modeling assumptions and is also shown to be
robust in the presence of measurement noise and generator parameter
uncertainty.Comment: 13 page