In this paper, we propose a measurement-based approach to the real-time economic dispatch (ED). The realtime ED is a widely used market scheduling problem seeking to economically balance electricity system supply and demand and provide locational marginal prices (LMPs) while respecting system reliability requirements. The ED is a convex optimization problem with a linear or quadratic objective, typically the minimization of generator costs or the maximization of social surplus. The constraints capture power balance and network flow capacity limits and are formulated using a linearized power flow model. Our approach utilizes power system sensitivities estimated from phasor measurement unit (PMU) measurements to reformulate the model-based power flow and network flow constraints. The resulting measurement-based real-time ED overcomes the vulnerabilities of the model-based real-time ED. The dispatch instructions and LMPs calculated with our measurement-based real-time ED accurately, and adaptively, reflect real-time system conditions. We illustrate the strengths of the proposed approach via several case studies.

10aAA05-0051 aVan Horn, Kai, E.1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/measurement-based-real-time-economic01739nas a2200181 4500008003900000022001400039245007100053210006800124260001200192300001100204490000700215520116700222653001301389100002201402700003601424700002101460856007601481 2015 d a0885-895000aMeasurement-Based Real-Time Security-Constrained Economic Dispatch0 aMeasurementBased RealTime SecurityConstrained Economic Dispatch c12/2015 a1 - 130 vPP3 aIn this paper, we propose a measurement-based approach to the real-time security-constrained economic dispatch (SCED). The real-time SCED is a widely used market scheduling tool that seeks to economically balance electricity supply and demand and provide locational marginal prices (LMPs), while ensuring system reliability standards are met. To capture network flows and security considerations, the conventional SCED formulation relies on sensitivities that are typically computed from a linearized power flow model, which is vulnerable to phenomena such as undetected topology changes, changes in the system operating point, and the existence of incorrect model data. Our approach to the formulation of the SCED problem utilizes power system sensitivities estimated from phasor measurement unit (PMU) measurements. The resulting measurement-based real-time SCED is robust against the aforementioned phenomena. Moreover, the dispatch instructions and LMPs calculated with the proposed measurement-based SCED accurately reflect real-time system conditions and security needs. We illustrate the strengths of the proposed approach via several case studies.

10aAA05-0051 aVan Horn, Kai, E.1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/measurement-based-real-time-security01622nas a2200157 4500008003900000245004800039210004700087260003800134300001000172520111500182653001301297100002201310700003601332700002101368856007501389 2015 d00aSensitivity-based line outage angle factors0 aSensitivitybased line outage angle factors aCharlotte, NC, USAbIEEEc10/2015 a1 - 53 aIn this paper, we propose a model-based approach to the computation of line outage angle factors (LOAFs), which relies on the use of angle factors (AFs) and power transfer distribution factors (PTDFs). A LOAF provides the sensitivity of the voltage angle difference between the terminal buses of a transmission line in the event the line is outaged to the pre-outage active power flow on the line. Large angle differences between the terminal buses of an outaged line can prevent the successful reclosure of the line-such an event was a significant contributing factor to the 2011 San Diego blackout. The proposed model-based LOAFs, along with the AFs and injection shift factors (ISFs), enable the fast computation of the impact on the angle across lines of line outages and active power injections, and provide system operators a systematic mean by which to assess line outage angles and undertake the appropriate dispatch actions necessary to alleviate large phase angle differences. We demonstrate the effectiveness of the proposed LOAFs with a case study carried out on the IEEE 14-bus test system.

10aAA05-0051 aVan Horn, Kai, E.1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/sensitivity-based-line-outage-angle01444nas a2200169 4500008003900000245009500039210006900134260003600203300001000239520085000249653000901099653001001108100002401118700003601142700002101178856007501199 2014 d00aGeneralized injection shift factors and application to estimation of power flow transients0 aGeneralized injection shift factors and application to estimatio aPullman, WA, USAbIEEEc09/2014 a1 - 53 aThis paper proposes a method to estimate transmission line flows in a power system during the transient period following a loss of generation or increase in load contingency by using linear sensitivity injection shift factors (ISFs). Traditionally, ISFs are computed from an offline power flow model of the system with the slack bus defined. The proposed method, however, relies on generalized ISFs estimated via the solution of a system of linear equations that arise from high-frequency synchronized measurements obtained from phasor measurement units. Even though the generalized ISFs are obtained at the pre-disturbance steady-state operating point, by leveraging inertial and governor power flows during appropriate time-scales, they can be manipulated to predict active transmission line flows during the post-contingency transient period.10aAARD10aCERTS1 aChen, Yu, Christine1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/generalized-injection-shift-factors01636nas a2200241 4500008003900000022001400039245009300053210006900146260001100215300001600226490000700242520084900249653000901098653003901107653001001146653001801156653003601174653002801210100002401238700003601262700002101298856007501319 2014 d a0885-895000aMeasurement-Based Estimation of Linear Sensitivity Distribution Factors and Applications0 aMeasurementBased Estimation of Linear Sensitivity Distribution F c5/2014 a1372 - 13820 v293 aIn this paper, we propose a method to compute linear sensitivity distribution factors (DFs) in near real-time. The method does not rely on the system power flow model. Instead, it uses only high-frequency synchronized data collected from phasor measurement units to estimate the injection shift factors through linear least-squares estimation, after which other DFs can be easily computed. Such a measurement-based approach is desirable since it is adaptive to changes in system operating point and topology. We further improve the adaptability of the proposed approach to such changes by using weighted and recursive least-squares estimation. Through numerical examples, we illustrate the advantages of our proposed DF estimation approach over the conventional model-based one in the context of contingency analysis and generation re-dispatch.10aAARD10aAutomatic Switchable Network (ASN)10aCERTS10aload modeling10aphasor measurement units (PMUs)10apower system monitoring1 aChen, Yu, Christine1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/measurement-based-estimation-linear01689nas a2200169 4500008003900000022001400039245009500053210006900148260001200217300001100229520111200240653000901352100002401361700003601385700002101421856007701442 2014 d a0885-895000aA Sparse Representation Approach to Online Estimation of Power System Distribution Factors0 aSparse Representation Approach to Online Estimation of Power Sys c10/2014 a1 - 123 aIn this paper, we propose a method to compute linear sensitivity distribution factors (DFs) in near real time without relying on a power flow model of the system. Specifically, we compute the injection shift factors (ISFs) of a particular line of interest with respect to active power injections at all buses (all other DFs can be determined from ISFs). The proposed ISF estimation method relies on the solution of an underdetermined system of linear equations that arise from high-frequency synchronized measurements obtained from phasor measurement units. We exploit a sparse representation (i.e., one in which many elements are zero) of the vector of desired ISFs via rearrangement by electrical distance and an appropriately chosen linear transformation, and cast the estimation problem into a sparse vector recovery problem. As we illustrate through case studies, the proposed approach provides accurate DF estimates with fewer sets of synchronized measurements than earlier approaches that rely on the solution of an overdetermined system of equations via the least-squares errors estimation method. 10aAARD1 aChen, Yu, Christine1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/sparse-representation-approach-online01617nas a2200217 4500008003900000245009600039210006900135260003800204300001000242520084800252653000901100653003901109653001001148653002501158653003601183653002901219100002401248700003601272700002101308856007001329 2013 d00aOnline estimation of power system distribution factors — A sparse representation approach0 aOnline estimation of power system distribution factors A sparse aManhattan, KS, USAbIEEEc09/2013 a1 - 53 aThis paper proposes a method to compute linear sensitivity distribution factors (DFs) in near real-time without relying on a power flow model of the system. Instead, the proposed method relies on the solution of an underdetermined system of linear equations that arise from high-frequency synchronized measurements obtained from phasor measurement units. In particular, we exploit a sparse representation (i.e., one in which many elements are zero) of the desired DFs obtained via a linear transformation, and cast the estimation problem as an IO-norm minimization. As we illustrate through examples, the proposed approach is able to provide accurate DF estimates with fewer sets of synchronized measurements than earlier approaches that rely on the solution of an overdetermined system of equations via the least-squares errors method.

10aAARD10aAutomatic Switchable Network (ASN)10aCERTS10adistribution factors10aphasor measurement units (PMUs)10apower system reliability1 aChen, Yu, Christine1 aDominguez-Garcia, Alejandro, D.1 aSauer, Peter, W. uhttps://certs.lbl.gov/publications/online-estimation-power-system00652nas a2200157 4500008003900000245013500039210006900174260001200243653001300255653003900268653003300307100002500340700002100365700003200386856007600418 2012 d00aReliability Performance Monitoring (RPM) Prototype Preliminary Validation Results, User Interface, Deployment Plan, and Field Test0 aReliability Performance Monitoring RPM Prototype Preliminary Val c03/201210aMISO-GPM10areliability metrics and monitoring10areliability monitoring tools1 aMartinez, Carlos, A.1 aSauer, Peter, W.1 aDominguez-Garcia, Alejandro uhttps://certs.lbl.gov/publications/reliability-performance-monitoring-001173nas a2200205 4500008003900000245004600039210004600085260001200131300000700143520057100150653001000721653002600731100002100757700002000778700002300798700002600821700002100847700002500868856007400893 2004 d00aIntegrated Security Analysis Final Report0 aIntegrated Security Analysis Final Report c07/2004 a723 aThis report presents results on the identification of the current state of power system security analysis for operations and the potential integration of the various existing power system security analysis tools. Current security analysis consists of numerous software tools (some off-line and some on-line) that predict operator guidelines for transaction scheduling. A survey of selected operators in representative locations in both the East and Western US was conducted to determine the effectiveness of current tools and the need for future improvements.

10aRTGRM10aSystem Security Tools1 aSauer, Peter, W.1 aTomsovic, Kevin1 aDagle, Jeffery, E.1 aWidergren, Steven, E.1 aNguyen, Tony, B.1 aSchienbein, Lawrence uhttps://certs.lbl.gov/publications/integrated-security-analysis-final