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

Novel Optimization-Based Algorithms for a Substation Voltage Controller Using Local PMU Measurements

This paper presents an improved version of a local voltage controller for a transmission substation. The controller uses available phasor measurement units (PMUs) at the substation, for optimal management of its local reactive (VAr) control resources, such as shunt reactive devices and transformer taps. Two optimization formulations with different objectives are introduced based on various operating criteria in electric utilities. The first approach aims to minimize the required reactive power injection such that it corrects the substation bus voltages to be within pre-specified limits so as to be close as possible to the optimal values. The second one minimizes the number of switching actions that are needed to correct the voltages to be within limits. Genetic algorithm (GA) is used for solving these discrete optimization problems. Performance of the proposed formulations is tested and analyzed through simulations for a typical substation in Southern California transmission network. Finally, the results from the two approaches are compared and discussed

Direct Computation of Generator Internal Dynamic States from Terminal Measurements

Abstract-- Estimating the dynamic state variables of a synchronous generator has been a long standing research problem in power system control designs. In this paper, we present a technique to compute approximately the state variables of a synchronous generator, purely from terminal measurements. The approximation follows from an analysis of the fundamental equations describing synchronous machine models. The method assumes the availablity of the measurements: real and reactive power, terminal voltage, and the field current. By exploiting the structure of the flux linkage equations, approximate formulas for the machine rotor angle (with respect to the phase of the terminal voltage) as well as for the internal flux linkages are derived, and they are shown to be excellent approximations in simulations of detailed machine models. Index Terms—Synchronous machine models, power system dynamics, power system models, power system controls. I

Abstract

dissertation of JINGDONG SU find it satisfactory and recommend that it be accepted. ii ACKNOWLEDGEMENT I would like to express my sincere appreciation to my advisor, Professor Vaithianathan Venkatasubramanian, for his valuable advice, skilled guidance and continuous support throughout my doctoral study. His profound knowledge and kindness will always be an inspiration to me. I am also grateful to Mr. Carson Taylor and Mr. Ramu Ramanathan for their counsel, insight and support. I have enjoyed the enlightening instruction and advisement of Professor Anjan Bose and Professor Kevin Tomsovic, and I am thankful for their participation in my advisory committee. Funding in part from Bonneville Power Administration (BPA) is gratefull