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- Chompoobutrgool, Yuwa, et al.
(author)
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A fundamental study on damping control design using PMU signals from dominant inter-area oscillation paths
- 2012
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In: North American Power Symposium (NAPS), 2012. - : IEEE. - 9781467323086 ; , s. 1-6
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Conference paper (peer-reviewed)abstract
- This article presents a fundamental study on feedback control using different types of signals available from a dominant inter-area oscillation path; the passageway containing the highest content of the inter-area oscillations. Results from the previous studies verify the persistence and robustness of dominant path signals and suggest that using such signals, effective damping control may be achieved. To corroborate the implication, signals available from phasor measurement units (PMU) e.g. voltage phasors (magnitude and angle) from the dominant path are used as feedback inputs for a power system stabilizer (PSS) control design for damping enhancement. The corresponding performance are compared with those using generator speed, which is a commonly used signal though not available from PMUs, as inputs. Contrary to expectations found in common practice, that of speed being the one of the most effective signal for damping control, it is demonstrated here that their corresponding damping performance is inferior to those using voltage phasors as feedback inputs. A conceptualized two-area system is used to analyze damping performance throughout this study.
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| 2. |
- Chompoobutrgool, Yuwa, 1984-, et al.
(author)
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Analysis of Time Delay Effects for Wide-Area Damping Control Design using Dominant Path Signals
- 2014
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In: 2014 IEEE Power and Energy Society General Meeting. - : IEEE Computer Society. - 9781479964154 ; , s. 6938872-
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Conference paper (peer-reviewed)abstract
- The purpose of this article is to investigate the effects of time delays for wide-area damping control design when signals from dominant inter-area oscillation paths are used as feedback inputs for damping controllers. The analysis is carried out using a two-area study system. Frequency and time-domain responses of a generator's terminal voltage when the PSS uses PMU signals subject to time delays will be compared and assessed. The analysis reveals that while modal observability of the dominant path signals corresponds to the gain of the open-loop system at the inter-area frequency, these properties are inversely proportional to their corresponding delay margins.
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| 3. |
- Chompoobutrgool, Yuwa, 1984-
(author)
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Aspects of Wide-Area Damping Control Design using Dominant Path Synchrophasor Signals
- 2015
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Doctoral thesis (other academic/artistic)abstract
- The presence of inter-area oscillations has long affected stability constraints, and therefore, limited the power transfer capacity of interconnected power systems. Adequate damping of these inter-area oscillations is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. Power system stabilizers (PSS) are the most common devices used to enhance the damping of such oscillations. Many studies have demonstrated that PSSs using remote signals may perform better than using local signals.The advent of phasor measurement units (PMU) makes remote or wide-area signals become available, which enables various important applications. Of particular interest is wide-area damping control (WADC), which aims to utilize remote or wide-area measurements to damp the inter-area oscillations. However, two main challenges in WADC design are (1) feedback controller input signal selection (which PMU signal is best to use?), and (2) latency (which is inherent in the transmission of the measurements) considerations.In response to the first challenge, this thesis proposes a concept called dominant inter-area oscillation path, which serves to pinpoint a set of candidate signals that can be used as the feedback controller inputs by locating the interconnected corridors where the inter-area modal contents are the most observable. Derivation, identification, and use of the dominant inter-area oscillation paths are demonstrated throughout the thesis. Extensive analysis on the relationships between the proposed set of signals and system properties regarding stability and robustness is presented. To tackle the second challenge, the impacts of time delays on the system performance when using the dominant path signals are investigated.To date, several studies have proposed different control design methods using various oscillation dampers to design WADC. Nevertheless, neither a systematic method nor a concept that encompasses fundamental knowledge on power system dynamics has yet been offered. The objective of this thesis is, thus, to propose an analytical framework based on the dominant path concept which is built upon fundamental principles for feedback controller input signal selection in WADC. With this framework, a proper and systematic approach is developed. The proposed method allows to select appropriate signals and use them to effectively mitigate the inter-area oscillations that constrain power transfer capacity and affect system stability.
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| 4. |
- Chompoobutrgool, Yuwa, 1984-
(author)
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Concepts for Power System Small Signal Stability Analysis and Feedback Control Design Considering Synchrophasor Measurements
- 2012
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Licentiate thesis (other academic/artistic)abstract
- In the Nordic power network, the existence of poorly damped low-frequency inter-area oscillations (LFIOs) has long affected stability constraints, and thereby, limited power transfer capacity. Adequate damping of inter-area modes is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. Power system stabilizers (PSS) is a prevalent means to enhance the damping of such modes. With the advent of phasor measurement units (PMUs), it is expected that wide-area damping control (WADC), that is, PSS control using wide-area measurements obtained from PMUs, would effectively improve damping performance in the Nordic grid, as well as other synchronous interconnected systems. Numerous research has investigated one ``branch'' of the problem, that is, PSS design using various control schemes. Before addressing the issue of controller design, it is important to focus on developing proper understanding of the ``root'' of the problem: system-wide oscillations, their nature, behavior and consequences. This understanding must provide new insight on the use of PMUs for feedback control of LFIOs. The aim of this thesis is, therefore, to lay important concepts necessary for the study of power system small signal stability analysis that considers the availability of synchrophasors as a solid foundation for further development and implementation of ideas and related applications. Particularly in this study, the focus is on the application addressed damping controller design and implementation. After a literature review on the important elements for wide-area damping control (WADC), the thesis continues with classical small signal stability analysis of an equivalent Nordic model; namely, the KTH-NORDIC32 which is used as a test system throughout the thesis. The system's inter-area oscillations are identified and a sensitivity analysis of the network variables directly measured by synchrophasors is evaluated. The concept of network modeshapes, which is used to relate the dynamical behavior of power systems to the features of inter-area modes, is elaborated. Furthermore, this network modeshape concept is used to determine dominant inter-area oscillation paths, the passageways containing the highest content of the inter-area oscillations. The dominant inter-area paths are illustrated with the test system. The degree of persistence of dominant paths in the study system is determined through contingency studies. The properties of the dominant paths are used to construct feedback signals as input to the PSS. Finally, to exemplify the use of the dominant inter-area path concept for damping control, the constructed feedback signals are implemented in a PSS modulating the AVR error signal of a generator on an equivalent two-area model, and compared with that of conventional speed signals.
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| 5. |
- Chompoobutrgool, Yuwa, et al.
(author)
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Development and Implementation of the Nordic Grid Model for Power System Small-Signal and Transient Stability Studies in a Free and Open Source Software
- 2012
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In: Power and Energy Society General Meeting, 2012 IEEE. - : IEEE. - 9781467327299 ; , s. 6344571-
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Conference paper (peer-reviewed)abstract
- This article presents an implementation of a Nordic grid model in Power System Analysis Toolbox (PSAT) -a free and open-source software. A newly developed hydro turbine and hydro governor (HTG) model is implemented with this grid model and compared with the currently available PSAT turbine and governor models. Small-signal and transient stability analyses of the system using the two models are carried out and compared to demonstrate the difference and necessity of accurate hydro turbine and governor model utilization. The paper ends with a validation of the linearized Nordic grid model generated by PSAT including the newly implemented HTG models. This validation is done through nonlinear time-domain simulation by applying both large and small disturbances.
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| 6. |
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| 7. |
- Chompoobutrgool, Yuwa, et al.
(author)
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Identification of power system dominant inter-area oscillation paths
- 2013
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In: IEEE Transactions on Power Systems. - 0885-8950 .- 1558-0679. ; 28:3, s. 2798-2807
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Journal article (peer-reviewed)abstract
- This paper presents three algorithms for identification of dominant inter-area oscillation paths: a series of interconnected corridors in which the highest content of the inter-area modes propagates through. The algorithms are developed to treat different sets of data: 1) known system model; 2) transient; and 3) ambient measurements from phasor measurement units (PMUs). These algorithms take feasibility into consideration by associating the network variables made available by PMUs, i.e., voltage and current phasors. All algorithms are demonstrated and implemented on a conceptualized Nordic Grid model. The results and comparison among three algorithms are provided. The applications of the algorithms not only facilitate in revealing critical corridors which are mostly stressed but also help in indicating relevant feedback input signals and inputs to mode meters which can be determined from the properties of dominant paths.
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| 8. |
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| 9. |
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| 10. |
- Chompoobutrgool, Yuwa, et al.
(author)
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On the persistence of dominant inter-area oscillation paths in large-scale power networks
- 2012
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In: IFAC Proceedings Volumes (IFAC-PapersOnline) Volume 8, Issue PART 1, 2012. - : Elsevier BV. - 9783902823243 ; , s. 150-155
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Conference paper (peer-reviewed)abstract
- This article discusses the degree of persistence of dominant inter-area oscillation paths: the passageways containing the highest content of inter-area oscillations in large-scale power networks. To this aim, a number of contingency studies are carried out: faults being imposed on the lines connecting to the dominant inter-area path. The path persistence is then examined using the relationship between sensitivities of network variables (i.e. voltages and current, magnitude and angle), and mode shapes describing the contribution of the oscillations among the generators variables (e.g. speed and angle). This relationship is termed network modeshape. The larger in magnitude and the lesser the variation the network modeshape is, the more observable and the more robust the signals measured from the dominant path becomes. The outcome is a proposed signal combination to be used as inputs to the damping controller for mitigation of inter-area oscillations in large-scale power systems.
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