Browsing by Author "Jones, Kevin David"
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- Power System Parameter Estimation for Enhanced Grid Stability Assessment in Systems with Renewable Energy SourcesSchmitt, Andreas Joachim (Virginia Tech, 2018-06-05)The modern day power grid is a highly complex system; as such, maintaining stable operations of the grid relies on many factors. Additionally, the increased usage of renewable energy sources significantly complicates matters. Attempts to assess the current stability of the grid make use of several key parameters, however obtaining these parameters to make an assessment has its own challenges. Due to the limited number of measurements and the unavailability of information, it is often difficult to accurately know the current value of these parameters needed for stability assessment. This work attempts to estimate three of these parameters: the Inertia, Topology, and Voltage Phasors. Without these parameters, it is no longer possible to determine the current stability of the grid. Through the use of machine learning, empirical studies, and mathematical optimization it is possible to estimate these three parameters when previously this was not the case. These three methodologies perform estimations through measurement-based approaches. This allows for the obtaining of these parameters without required system knowledge, while improving results when systems information is known.
- Synchrophasor-Only Dynamic State Estimation & Data ConditioningJones, Kevin David (Virginia Tech, 2013-08-30)A phasor-only estimator carries with it intrinsic improvements over its SCADA analogue with respect to performance and reliability. However, insuring the quality of the data stream which leaves the linear estimator is crucial to establishing it as the front end of an EMS system and network applications which employ synchrophasor data. This can be accomplished using a two-fold solution: the pre-processing of phasor data before it arrives at the linear estimator and the by developing a synchrophasor-only dynamic state estimator as a mechanism for bad data detection and identification. In order to realize these algorithms, this dissertation develops a computationally simple model of the dynamics of the power system which fits neatly into the existing linear state estimation formulation. The algorithms are then tested on field data from PMUs installed on the Dominion Virginia Power EHV network.
- Three-Phase Linear State Estimation with Phasor MeasurementsJones, Kevin David (Virginia Tech, 2011-05-02)Given the ability of the Phasor Measurement Unit (PMU) to directly measure the system state and the increasing implementation of PMUs across the electric power industry, a natural expansion of state estimation techniques would be one that employed the exclusive use of PMU data. Dominion Virginia Power and the Department of Energy (DOE) are sponsoring a research project which aims to implement a three phase linear tracking state estimator on Dominion's 500kV network that would use only PMU measurements to compute the system state. This thesis represents a portion of the work completed during the initial phase of the research project. This includes the initial development and testing of two applications: the three phase linear state estimator and the topology processor. Also presented is a brief history of state estimation and PMUs, traditional state estimation techniques and techniques with mixed phasor data, a development of the linear state estimation algorithms and a discussion of the future work associate with this research project.
- Transmission Lines Positive Sequence Parameters Estimation and Instrument Transformers Calibration Based on PMU Measurement Error ModelWang, Chen; Centeno, Virgilio A.; Jones, Kevin David; Yang, Duotong (IEEE, 2019-10-17)Phasor Measurement Unit measurement data have been widely used in nowadays power system applications both in steady state and dynamic analysis. The performance of these applications running in utilities' energy management system depends heavily on an accurate positive sequence power system model. However, it is impractical to nd this accurate model with transmission line parameters calculated directly with the PMU measurements due to ratio errors brought by instrument transformers and communication errors brought by PMUs. Therefore, a methodology is proposed in this paper to estimate the actual transmission lines parameters throughout the whole system and, at the same time, calibrate the corresponding instrument transformers. A PMU positive sequence measurement error model is proposed targeting at the aforementioned errors, which is applicable to both transposed and un-transposed transmission lines. A single line parameters estimation method is designed based on Least Squares Estimation and this error model. This method requires only one set of reference measurements and the accuracy can be propagated throughout the whole network along with the topology acquired by the introduced Edge-based Breadth-rst Search algorithm. The IEEE 118-bus system and the Texas 2000-bus system are used to demonstrate the effectiveness and efciency of the proposed method. The potential for deployment in reality is also discussed.