TY - RPRT
T1 - Detection of Forced Oscillations in Power Systems with Multichannel Methods
Y1 - 2015/09//
A1 - Jim Follum
KW - AA09-002
KW - AARD
AB - The increasing availability of high fidelity, geographically dispersed measurements in power systems improves the ability of researchers and engineers to study dynamic behaviors in the grid. One such behavior that is garnering increased attention is the presence of forced oscillations. Power system engineers are interested in forced oscillations because they are often symptomatic of the malfunction or misoperation of equipment. Though the resulting oscillation is not always large in amplitude, the root cause may be serious. In this report, multi-channel forced oscillation detection methods are developed. These methods leverage previously developed detection approaches based on the periodogram and spectral-coherence. Making use of geographically distributed channels of data is shown to improved detection performance and shorten the delay before an oscillation can be detected in the online environment. Results from simulated and measured power system data are presented.
PB - Pacific Northwest National Laboratory
ER -
TY - JOUR
T1 - Detection of Periodic Forced Oscillations in Power Systems
JF - IEEE Transactions on Power Systems
Y1 - 2015/08//
SP - 1
EP - 11
A1 - Jim Follum
A1 - John W. Pierre
KW - AA09-002
AB - An algorithm for the detection and frequency estimation of periodic forced oscillations in power systems is proposed. The method operates by comparing the periodogram of synchrophasor measurements to a detection threshold. This threshold is established by deriving a general expression for the distribution of the periodogram and is related to the algorithm's probabilities of false alarm and detection. Unlike classic detection algorithms designed for use with white Gaussian noise, the proposed algorithm uses a detection threshold that varies with frequency to account for the colored nature of synchrophasor measurements. Further, a detection method based on multiple segments of data is also proposed to improve the algorithm's performance as a monitoring tool in the online environment. A design approach that helps to ensure that the best available probability of detection from any one detection segment is constantly increasing with the duration of the forced oscillation is also developed. Results from application of the detection algorithm to simulated and measured power system data suggest that the algorithm provides the expected detection performance and can be used to detect forced oscillations in practical monitoring of power systems.
JO - IEEE Trans. Power Syst.
DO - 10.1109/TPWRS.2015.2456919
ER -
TY - CONF
T1 - Time-localization of forced oscillations in power systems
T2 - 2015 IEEE Power & Energy Society General Meeting2015 IEEE Power & Energy Society General Meeting
Y1 - 2015/07//
SP - 1
EP - 5
A1 - Jim Follum
A1 - John W. Pierre
KW - AA09-002
AB - In power systems forced oscillations occur, and identification of these oscillations is important for the proper operation of the system. Two of the parameters of interest in analyzing and addressing forced oscillations are the starting and ending points. To obtain estimates of these parameters, this paper proposes a time-localization algorithm based on the geometric analysis of the sample cross-correlation between the measured data and a complex sinusoid at the frequency of the forced oscillation. Results from simulated and measured synchrophasor data demonstrate the algorithm's ability to accurately estimate the starting and ending points of forced oscillations.
JF - 2015 IEEE Power & Energy Society General Meeting2015 IEEE Power & Energy Society General Meeting
PB - IEEE
CY - Denver, CO, USA
DO - 10.1109/PESGM.2015.7286129
ER -
TY - JOUR
T1 - A Generalized Subspace Least Mean Square Method for High-resolution Accurate Estimation of Power System Oscillation Modes
JF - Electric Power Components and Systems
Y1 - 2013/09//
SP - 1205
EP - 1212
A1 - Peng Zhang
A1 - Ning Zhou
A1 - Ali Abdollahi
KW - AA09-002
KW - AARD
KW - Automatic Switchable Network (ASN)
KW - oscillations
AB - A generalized subspace least mean square method is presented for accurate and robust estimation of oscillation modes from exponentially damped power system signals. The method is based on the orthogonality of signal and noise eigenvectors of the signal autocorrelation matrix. Performance of the proposed method is evaluated using Monte Carlo simulation and compared with the Prony method. Test results show that the generalized subspace least mean square method is highly resilient to noise and significantly dominates the Prony method in tracking power system modes under noisy environments.
VL - 41
IS - 12
JO - Electric Power Components and Systems
DO - 10.1080/15325008.2013.807896
ER -
TY - CONF
T1 - Evaluation of mode estimation accuracy for small-signal stability analysis
T2 - 2011 North American Power Symposium (NAPS 2011)
Y1 - 2011/08//
SP - 1
EP - 7
A1 - Jim Follum
A1 - Ning Zhou
A1 - John W. Pierre
KW - AA09-002
KW - AARD
KW - Automatic Switchable Network (ASN)
KW - load modeling
KW - power system monitoring
AB - This paper proposes a method for determining electromechanical mode estimate accuracy by relating mode estimate error to residual values. Mode frequency and damping ratio were estimated using Prony analysis and residuals were calculated for a 17-machine model with varying levels of load noise. Mode estimate error and residuals were found to increase proportionally to each other as noise values were increased, revealing a distinctly linear relationship. The use of these results to develop appropriate confidence in models is discussed. With the relationship established, a method of predicting mode estimate error values based on residuals in the western North American power system (wNAPS) was developed. The potential of this method to evaluate the confidence level of mode estimates is examined.
JF - 2011 North American Power Symposium (NAPS 2011)
PB - IEEE
CY - Boston, MA, USA
SN - 978-1-4577-0417-8
DO - 10.1109/NAPS.2011.6024893
ER -
TY - CONF
T1 - A modified stepwise linear regression method for estimating modal sensitivity
T2 - IEEE Power and Energy Society (PES) General Meeting
Y1 - 2011/07//
SP - 1
EP - 7
A1 - Ning Zhou
A1 - Zhenyu Huang
A1 - Francis K. Tuffner
A1 - Dan Trudnowski
A1 - William A. Mittelstadt
KW - AA09-002
KW - AARD
KW - Automatic Switchable Network (ASN)
KW - phasor measurement units (PMUs)
KW - power system reliability
AB - Small signal stability problems are one of the major threats to grid stability and reliability. Low damping of inter area modes is usually considered to be a result of heavy power transfer over long distances. This paper proposes a modified stepwise regression method to estimate the modal sensitivity with respect to power flow on the transmission lines based on measurement. This sensitivity is used to identify dominant transmission lines, whose power flow has significant influence on the inter-area modal damping. It is shown through simulation study that the proposed method can effectively estimate the modal sensitivity with respect to line power flow. This, in turn, provides insight on how to improve damping through adjusting tie line flow.
JF - IEEE Power and Energy Society (PES) General Meeting
PB - IEEE
CY - Detroit, MI, USA
SN - 978-1-4577-1000-1
DO - 10.1109/PES.2011.6039795
ER -